Commodore 64

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Commodore 64
Commodore 64

Logo of the Commodore 64
Manufacturer Commodore International
Type Home computers
publication 1982
End of production 1994
Factory price 1495 DM (when sales started in Germany in 1983)
processor MOS 6510 / 8500
@ 1.023 MHz (NTSC version)
@ 0,985 MHz (PAL version)
random access memory 64 KB RAM + 20 KB ROM
graphic VIC II (320 × 200, 16 colors, sprites )
Sound SID 6581 (3 × Osc, 4 × Wave, Filter, ADSR, Ring)
Disk optional: 170 KB floppy disks, audio cassettes ( Datasette ), plug-in modules
operating system Commodore Basic V2 , GEOS 64
predecessor Commodore VC 20
successor Commodore 128 ;
Commodore 65 (not ready for series production)

The Commodore 64 (briefly C64 , commonly known as '64 or "bread box" ) is an 8-bit - home computer with 64  KB of RAM .

Since its presentation in January 1982 at the Winter Consumer Electronics Show , the C64 built by Commodore has been extremely popular in the mid to late 1980s both as a game computer and for software development . It is considered to be the best-selling home computer worldwide - sales estimates range between 12.5 and 30 million copies. The C64 offered a lot of technology and good expandability at an affordable price (after the introductory phase).

In contrast to modern PCs , the C64, as was common with home computers at that time, had no internal mass storage devices . All programs had to external drives, such as the cassette drive Datasette or 5¼ "- floppy drive VC1541 , or a plug-in module (cartridge) are loaded. Only basic functions such as the Kernal , the BASIC interpreter and two screen fonts were stored in three ROM chips with storage capacities of two times eight and one time four KB.



C64C system with VC1541 -II floppy disk drive and RGB monitor 1084S (1986), the status is displayed immediately after switching on (start screen)

In January 1981 the former MOS Technology , now a subsidiary of Commodore International as Commodore Semiconductor Group, began developing a new chipset for graphics and audio for a next-generation game console. Work on the two chips VIC II (graphics) and SID (audio) was successfully completed in November 1981. The Japanese engineer Yashi Terakura from Commodore Japan then developed the Commodore Max computer (announced in Germany as VC 10) based on the two new chips . However, production was stopped shortly after the first Commodore MAX were delivered in Japan.

In mid-1981, Robert Russell (system programmer and developer of the VC 20) and Robert "Bob" Yannes (developer of the SID) made CEO with the support of Al Charpentier (developer of the VIC-II) and Charles Winterble (manager of MOS Technology) Commodore International, Jack Tramiel , proposed to build a real low-cost computer from the developed chips, which was to become the successor to the VC 20. Tramiel agreed and explained that the computer should have an increased memory of 64 KB RAM, using the full address space of 16 bits. Even if 64 KB of RAM cost more than 100 US dollars at that time, he assumed that RAM prices would drop to an acceptable price by the time the C64 was fully launched. Tramiel also set the deadline for the presentation of the computer at the beginning of the Consumer Electronics Show (CES) in January 1982 in Las Vegas . The meeting took place in November 1981, so that the developers only had two months to build prototypes of the computer.

The project initially had the code name VC-40, which was chosen based on the predecessor model VC-20. The team that developed the device consisted of Robert Russell, Robert "Bob" Yannes and David A. Ziembicki. The design of the C64, prototypes and some example software were finished just in time for the CES in Las Vegas after the team had worked through the entire Christmas period (including the weekends). The 40 in the name should indicate the text resolution of 40 characters per line. Commodore set this resolution, among other things, in order to remain below the performance of its own computers of the CBM-8000 series intended for professional use , which at the time had the same processor speed, smaller or the same memory configuration, only monochrome or significantly limited color options and a little more powerful BASIC 4.0 were offered. A characteristic factor for the professional applicability at that time was the possibility to display text lines for the print output in full width, for which 80 characters were necessary.

Motherboard of a C64 (1982)
Motherboard of a C64C (1992)

During the production period of the C64, optical and technical details were changed again and again in order to take advantage of modern manufacturing possibilities and to reduce production costs. Although the inner workings of the first C64 differ significantly from that of the last version, the developers managed to keep all versions of the software almost 100% compatible with each other - which meant that the performance of the computer was not increased during the production cycle. For example, the motherboard layout was changed several times and the CPU , graphics chip , sound chip and other components were revised. The logic chips required for interconnection within the computer were also combined and integrated into a custom chip .

In contrast to other home computers at the time, there were no replicas of the C64 from Eastern Bloc countries, Latin America or the Far East. This is mainly due to the highly integrated construction with custom chips and the vertical integration of the Commodore company - from chip production to chip design and system design to housing design, everything was in one hand, which means that these chips were not available for replicas.


Before the C64, Commodore Business Machines (CBM) had already successfully introduced the office computer PET 2001 and its successors, but also the home computer VC 20 . Company founder Jack Tramiel coined the formula “We need to build computers for the masses, not the classes!”, Which he ultimately succeeded in with the C64.

In order to be able to integrate the new development into the existing product range, the marketing department decided on the name "C64", which should stand for "consumer" and the size of the memory used in KB. Models named after the same scheme, the Business 256 and the P (personal computer) 128, were already planned for the American market. The latter belonged to the series published in Europe as the Commodore CBM 500 and is not identical to the later C128 .

In September 1982 the C64 came to the American market for 595 US $ and at the beginning of 1983 at a starting price of 1,495 DM (in today's purchasing power 1,470 €) and was in Germany , as in all important markets of the world (with the exception of Japan ) , very successful. As early as 1983, the price fell to mostly 698 DM.

Main competitor was the United States strongly represented Atari 800 XL . Many games were available on a 5¼-inch diskette for both systems at the same time , such as the computer role-playing game Alternate Reality (front side C64, rear side Atari), which can be seen as an indication of the dominance of the two brands. Despite the competition from Atari and many other home computers at this time ( TI-99 / 4A , Apple II , Sinclair ZX81 , ZX Spectrum , Dragon 32 ), many consumers rated the price-performance ratio of the C64 as favorable at the beginning of its delivery. In combination with the rapidly increasing number of software titles for the C64, the computer developed into a success. The fact that the computer was not only for sale in specialty stores, but also in department store chains, mail order companies (e.g. Quelle ), supermarket chains (e.g. allkauf ) and computer mail order companies (e.g. Vobis ) also contributed to contributed to the fact that the device was a complete success in a short time. With the rise of the C64 as a home computer came the final fall of the most widespread console to date, the Atari VCS 2600 .

Commodore produced the C64 for about eleven years; over 22 million units were sold (other sources give 17 million). This makes the C64 the best-selling computer in the world.

Technical details

Block diagram of the C64


MOS-6510 processor

The processor is a 6510 (8500 for the C64C / II), a variant of the 6502 from MOS Technology. Commodore bought this company in the mid-1970s in order to have its own semiconductor factory . In contrast to the 6502, the 6510 has a 6-bit wide bidirectional I / O port, which can be addressed via the memory addresses 0 and 1 and, among other things, is used on the C64 to switch between RAM, ROM and I / O -Switch range through bank switching .

The processor works with a clock frequency of 0.985249  MHz in the PAL version and 1.022727 MHz in the NTSC version. The difference arises from the fact that in the C64 all the required frequencies are simply derived from the oscillation frequency of only one quartz oscillator and that the color carrier frequencies of the two color transmission systems have different values ​​that must be adhered to. In the NTSC version, more clock cycles per raster line are available in the graphics output, and the CPU is also somewhat faster overall. In return, NTSC has fewer lines per (half) picture, only 262 compared to 312 with PAL. Therefore programs that use the raster line interrupt (see below) for image-synchronous sequence control must have interchangeable code parts for both C64 versions or be available in two different versions.


Memory structure of the C64

The C64 has 64 KB of RAM . 38,911 bytes of this can be used for BASIC programs. The size of the memory was generous for the time (the two years older predecessor VC 20 has only 5 KB of working memory, of which 3584 bytes can be used for the BASIC programming language). Two bytes (0 and 1) cannot be used for the RAM; this is where the processor port of the 6510 is located.


The two PETSCII character sets of the C64:
a) small and large letters, b) large letters and block graphics

The C64 has 20 KB of ROM . About 9 KB of it contain the BASIC V2 interpreter of the older Commodore VC 20 (published 1980), which originally comes from Microsoft , in an almost unchanged form . In just under 7 KB there is an operating system , the so-called Kernal , which contains the keyboard, the screen, the cassette interface , the RS-232 interface and a serial IEC interface (the CBM bus ) for controlling printers, floppy drives, etc. managed. This also originally comes from older Commodore machines and was adapted to the changed hardware of the C64. The remaining 4 KB contain two character sets of 256 characters each in an 8 × 8 matrix display for the screen. The character sets correspond to Commodore's own PETSCII standard and therefore do not contain any German umlauts .

In order to remain compatible across different versions at the machine language level, $FFFFa jump table was created at the very end of the ROM area (i.e. shortly before ) , via which the most important operating system routines could be called. Commodore kept this jump table from the PET 2001 to beyond the C64. The compatibility of application software has not increased that much, because many programmers simply ignored this compatible method of calling and it was only useful for purely text-based programs anyway. - Example: The call JSR $FFD2 outputs the contents of the accumulator as characters on the screen on every Commodore 8-bit computer.


The VIC II 8565R2 for the C64 II
A C64
HiRes graphic with chips drawn with GeoPaint

The graphics chip of the C64 is a MOS 6569/8565 (PAL) or MOS 6567 (NTSC) and is called VIC ( V ideo I nterface C ontroller). He offers:

  • 16 colors: By taking advantage of a special feature of the PAL television standard (color information, chroma, is mixed between adjacent lines), new color mixtures can be created by arranging different colors vertically.
  • 40 × 25 character text mode (standard): 8 × 8 pixels per character, user-defined character sets possible. Screen-wide uniform background color, selectable foreground color for each character; up to 256 different characters can be used at the same time.
  • 40 × 25-character text mode (multicolor): 4 × 8 double-wide pixels per character, user-defined character sets possible. Up to four colors per character: three screen-wide uniform, one per character selectable; up to 256 different characters can be used at the same time.
  • 40 × 25-character text mode (extended background colors): Like standard text mode, but only 64 different characters, for each character one of up to four screen-wide background colors can be selected.
  • 160 × 200 double-wide pixels: in low-resolution bitmap mode (multicolor). All 16 colors can be used with restrictions (three individual colors per 4 × 8 pixel block plus one screen-wide color).
  • 320 × 200 pixels: in high-resolution bitmap mode ( HiRes ). All 16 colors can be used with severe restrictions (two individual colors each 8 × 8 pixel block).
  • Hardware scrolling : shifting the overall image vertically and / or horizontally by 0 to 7 pixels, together with further shifting by software, enables smooth, pixel-precise scrolling.
  • Eight sprites : each with a size of 24 × 21 pixels for single-color sprites (12 × 21 double-width pixels for multicolor sprites; both sprite types can be used simultaneously and in all screen modes). So-called sprite multiplexing made it possible to multiply the number of representable sprites. If sprites collide with each other or with the background graphic, an interrupt can be triggered.
  • Raster line interrupts: Interrupt request to the main processor when reaching an image line previously defined by the software.

Since the VIC only has 14 address lines, it can only address 16 KB of the available memory at a time. The two missing address bits are provided by the second CIA6526 chip built into the C64. These four 16 KB memory pages do not behave in the same way - the VIC always reads the character generator ROM in the memory area $1000to $1fff(or $9000to $9fff) . Screen memory (text or bitmap) and sprite data cannot be stored in these areas. Conversely, a character generator must be stored in the RAM on the other two memory pages in text mode.

The color RAM, which from the point of view of the main processor can be faded in at addresses $d800to $dbff, is a single 1024 × 4-bit SRAM chip (µPD2114) that has four separate data inputs in the VIC for timing reasons. The color RAM therefore does not have to be displayed in the "normal" VIC address space. In fact, the C64 has 66048 bytes of RAM. Since the last 24 addresses are not needed for the color display, the memory cells behind them can be used for special purposes.

The VIC also takes care of the necessary refresh of the DRAM chips of the C64 by regularly reading out all memory pages, as was common back then for graphics hardware .

Thanks to the raster line interrupts and the graphic chip design, the C64 is quite flexible in its image structure. Many of the hardware limitations can be circumvented through creative programming and the use of side effects not explicitly implemented by the manufacturer. For example, different display modes can be mixed (e.g. upper half of the screen with text display with scrolling, lower half of the screen with graphics) and the eight sprites can be used multiple times in different image areas, so that many games can display far more than eight sprites. By taking advantage of undocumented video chip properties, it is also possible to use additional video modes that partially remove the restrictions in color selection and resolution. The screen frame can also be used to display graphics with a few tricks.

The basic interpreter does not provide any commands for programming the high-resolution graphics, so that normal users cannot use them. This is remedied by commercial basic extensions such as Simons' Basic , s. u.


Sounds are generated by the three-part polyphonic sound chip MOS Technology SID 6581 (bus-compatible with the processor family 65xx), which gave the C64 revolutionary sound generation capabilities that went far beyond other home computers. Later C64 variants included the 8580.

The SID has three universal monophonic voices with a base frequency of 0 to 4000 Hz and 48 dB modulation that can be set in 65536 steps, which can simultaneously generate four waveforms (triangle, sawtooth, rectangle in 4096 steps, adjustable pulse width, as well as noise) in subtractive synthesis . The volume of each voice can be set individually using three programmable ADSR envelope generators with exponential curves. It is also possible to synchronize two or all three oscillators. A ring modulator gives further effects. One of the voices can also optionally be used to modulate the other voices only.

Furthermore, the SID has a subtractive multimode filter ( low pass , high pass , band pass or notch filter ) through which the internal voices and an external source that can be added via the monitor socket of the C64 can be fed.

Since the volume of the sound playback could be set in 16 steps, some programs soon used the volume control as a D / A converter to play back samples, for example speech or drums. Well-known examples of this are the game for the film "Ghostbusters" and the music game "To Be on Top". The sound quality was not particularly good, however, and there was also an incompatibility between the original and the later C64 versions: The later installed SID II (MOS 8580) only switched its output through when a sound was played on at least one voice. This reduced the background noise when there was no sound reproduction, pure samples without background music were only played very quietly. Newer programs take this fact into account, there were usually no adjustments for older software.

By cleverly mixing different samples, it was also possible to play back several samples at the software level; However, this inevitably resulted in a limitation of the playback accuracy (resolution) or the playback rate (sample / playback rate), that is, the tones generated in this way were less well resolved and “less precise”. A number of well-known game music programmers have made use of this technique.

In addition to audio playback, the SID also had two analog inputs with a low sampling rate, which were used in the C64 to connect paddles or a special mouse with an analog output.

At the end of the C64 era, methods were developed in hobbyist circles to make the C64 stereo-capable. For this purpose, a second SID was installed and the fact that the address area of ​​the SID is mirrored several times was used for control. With a suitable address selection, both SIDs could be controlled independently of one another. This solution was described as building instructions in the 64'er , but never came onto the market commercially.


Interfaces of the C64 (from left to right: joystick 1, joystick 2, power connection; expansion port, HF antenna output, video port, serial port, cassette port, user port)

The C64 offers several interfaces and was therefore popular with hardware hobbyists (from left to right, viewed from the rear):

  • Two joystick , paddle and mouse inputs : (9-pin Sub-D connector ) according to the Atari 2600 - de facto standard with digital inputs for joysticks (up / down / left / right / fire) or a digital one Mouse (Commodore 1350) and analog inputs for paddles or an analog mouse (Commodore 1351) . One of the entrances can be used for light pens. These interfaces are located on the side, along with the main switch and the connection for the power supply unit.
  • Expansion port (44-pin circuit board connector ): data and address bus brought out; for the direct insertion of hardware extensions, e.g. B. game modules, memory expansions, accelerator cards, etc. This port corresponds to the slots of today's PC.
  • High-frequency (HF) output ( cinch socket, HF modulator ): for connecting a television via its antenna socket (often the only connection option for devices at the time), fine adjustment on the left.
  • Audio / video output (8-pin DIN socket , 5-pin in early C64): with a composite video signal for connecting a video monitor or a television. In the case of the C64 with an 8-pin socket, an S-Video signal (luminance and chrominance signals separately) is also provided, which can be used for better picture quality. There is also an audio input for filtering an external audio signal through the SID filter.
  • Serial bus ( CBM bus , 6-pin DIN socket): for example for printers and floppy drives .
  • Connection option for a datasette (6 circuit board contacts)
  • User port (24 board contacts): One of the eight-bit wide bidirectional ports and one of the serial shift registers of the C64 are brought out here. The C64 does not contain a UART chip, but the C64-ROM has a software implementation of an RS-232 protocol that generates the necessary signals by means of bit banging . This can be used up to 2400 baud , but not at full speed with pure basic control. A level converter is required for the complete RS-232 interface, which converts the TTL level (0 V / + 5 V) to the RS-232 level of ± 12 V. Other typical applications for this port are the implementation of a Centronics printer interface (parallel port, requires additional driver software), parallel cables to a floppy disk drive, relay cards, EPROM burners or modems .


A large selection of peripheral devices could be purchased for the C64 .


Cassette drive

The tape drive called " Datasette " (also known as Datassette) was the cheapest solution for data storage on the C64. It uses normal compact cassettes . Usually software on cassettes was cheaper than the corresponding floppy disk versions. Unlike in Germany, where the floppy disk drive was very widespread (despite higher acquisition costs), the Datassette was the dominant data device in Great Britain. Commodore offered the VC-1530 data cassette drive, which was compatible with the C64. Other manufacturers also offered Datassette drives for the C64 and C128. Loading and saving processes are very slow and are cumbersome due to the necessary winding processes. Fast chargers like Turbo Tape reduce loading times by a factor of around 10.

5¼ inch floppy disk drive

This VC1541 drive was the standard drive for the C64. It used the then very widespread 5¼-inch floppy double recording density ( double-density ). The drive works on one side and offers about 165 kB of storage capacity per disk side. However, the available “blocks” are specified, of which there are 664 as standard. In order to be able to write on the back, the disk must be removed from the drive and turned over. There were floppy disks that could be written on both sides; if they were intended specifically for use with the C64, they had recesses on both sides for the write release. There were also cheaper floppy disks that were officially writable on one side only, and the back of the disks could sometimes also be written on. With these, a second notch always had to be punched out on the side beforehand, for example using a disk hole punch or a carpet knife. The drives will recognize the data as write-protected if this notch is covered. Corresponding stickers were included with the disks.

Older versions of the VC1541 had no way of recognizing when the read / write head had reached the lower end ("track 0") and therefore had a mechanical lock. This led to the well-known mechanical "rattling" of the drive when formatting a floppy disk, as the read / write head hit the stop up to five times - this allowed it to be adjusted. Newer versions had a light barrier to solve the problem; However, since the ROM of the drive was changed, this sometimes led to incompatibilities with quick loaders and copy protection mechanisms.

The drive was a stand-alone computer with its own processor and memory. Unlike practically all other companies, Commodore had implemented DOS as a ROM in the drive itself, instead of loading it into the computer's memory. There were programs that outsourced parts of the arithmetic work to the drive and thus enabled a kind of parallel programming; this was of limited use because of the small memory of the drive. There were also joke programs that even generated music with the drive through creative programming of the stepper motor responsible for the read / write head movement .

Three main and many sub-variants of the drive were made. Third-party manufacturers offered clones that were cheaper, but mostly not fully compatible because of the different ROMs due to copyright reasons.

The speed of the diskette operations was very slow due to the low memory expansion of the drives, the serial interface as well as the cumbersome programming of the DOS functions - the 1541-DOS was derived from that of the double processor double floppy CBM 8050 - so that many different turbochargers are available as software or were developed as hardware accelerators.

These accelerators were the first to write their own routines, developed in assembler , into the memory of the drive, which then implemented the data transfer together with routines running in the computer.

3½-inch floppy disk drive

Due to its incompatibility with the VC1541, the VC1581 type drive only had a shadowy existence in connection with the C64 - despite its considerably increased storage capacity of 800 kB on 3½-inch DD disks compared to the VC1541. Because of copy protection measures, many programs required the VC1541 drive, so the model 1581 was unsuccessful. Like the VC1541, this drive was technically a standalone computer.

Input devices

Commodore mouse 1350/1351

Mice played a subordinate role as input devices on the C64, as they only established themselves years after their introduction. There were only a few programs that supported them or were designed for use with the mouse (instead of a joystick). B. the graphics-oriented operating system GEOS , Hi-Eddi and Printfox .


In addition to the keyboard, joysticks are the most important input devices on the C64, because almost all games and many applications can only be controlled with them. The Atari standard for joysticks, which was quite widespread at the time, is supported on the C64, so that the same joysticks could be used as on many other computers. Commodore made its own joysticks, but Spectravideo's QuickShot joysticks, joysticks from QuickJoy and - due to its robustness - the Competition Pro were more popular and widespread .

Koala pad

Graphics tablet for the C64, which was developed for the graphics program KoalaPainter , but was also used by some other programs.

Light pen

Light pens are “pens” that are used to draw directly on the monitor. Like paddles, they hardly had any meaning on the C64.

Light gun

A lightgun is similar to the functionality of the light pen, but mostly in the shape of a pistol and intended for games. This input device was hardly of any importance for the C64.


Paddles are input devices that were widely used in many video games in the 1970s and found their way to the C64. Except for a few of the early C64 games and a few later exceptions such as Arkanoid , paddles had hardly any meaning on the C64.


A black-and-white scanner was available from Scanntronik , which was attached to the print head of a suitable needle printer and scanned the image to be scanned line by line while it was being transported by the printer roller, as well as a hand scanner .

Output devices

Commodore matrix printer MPS 802


Commodore sold its own printer models MPS 801 , -802 , -803 and -1230 (mainly Seikosha- OEM , e.g. the identical GP 500 VC). Due to technical limitations ( Unihammer technology with the MPS 801/803) or the fact that only 8 of the 9 available needles were activated (MPS 802), these matrix printers can not print real descenders in text mode . However, there were some software solutions on offer for this problem. Third-party manufacturers produced some special printers for Commodore computers that are connected to the serial bus of the C64 like a floppy disk drive, e.g. B. the very popular Star LC10. Two other solutions were widespread: You could connect common printers with Centronics interface to the serial IEC bus of the C64 via a special converter and then control them like Commodore printers, or you could connect them to the user port using a simple cable but then software that offered special support for this connection mode. Such routines were already integrated in some floppy quick loaders (e.g. SpeedDOS). There were electric typewriters that could be controlled by these interfaces and used as printers. At the driver level there are two standards, the MPS-801/803 mode and the Epson FX-80 mode (ESC-P) for nine-wire printers. The NEC-P6 standard was only rarely supported, as most NEC-P6-compatible printers are also FX-80-compatible, even though the output was then only done with nine needles. The vast majority of printers at that time were needle printers with 7, 8, 9 or 24 needles, whereby 24-needle printers were rather rare due to their high price and could only be used with special software. In the lowest price segment there were some thermal printers , but they were not widely used because of their poor print image, the expensive thermal paper required and the poor durability of the print. Inkjet printers , thermal transfer printers and laser printers were still very expensive at that time and therefore seldom found among home computer users.

Commodore 1702 video monitor

TV / monitor

With the help of the HF output, the C64 could be connected to any television via the antenna socket, so that no additional monitor was necessary to operate the computer. The image quality was naturally poor due to the implementation.
There was a large selection of video monitors for the C64 and other 8-bit home computers at the time. Above all, the Commodore 1701 and the Philips CM8833, with resolutions of 300 × 300 pixels, as well as the compatible monitors of the Amiga series, which provided a sharper image due to their finer shadow mask, should be mentioned here.


The Commodore VC-1520 plotter , a simple pen plotter for continuous roll paper , was less common . The paper roll was about 10 cm wide. The device offered the possibility of simple text output in red, green, blue and black. In addition, drawings could be output in the same colors.

Dial-up devices

Commodore VICMODEM model 1600 for VC20 and C64

Acoustic coupler

At that time it was illegal to operate modems on the German telephone network that were not certified by the Deutsche Bundespost - and most of them were - so that one had to use so-called acoustic couplers instead of these modems . However, the transmission was very slow, typically 300 to 1200 bit / s and also very error-prone, as background noise often led to transmission errors.


There were special C64 modems that were connected to the user port of the C64, as well as others that could be operated on the C64 with the help of an RS-232 interface (possibly to be connected to the expansion port) .

Network cards

In 2003 individual Computers launched a network adapter for the C64 under the name RR-Net . For operation, however, you need the Retro Replay Cartridge or the MMC64 , which was also released by individual Computers.

Further peripherals


A flash memory based module that can replace many ROM based modules. The basic idea was to make the “big” Ocean game modules replaceable by writing the content of such a module to the flash memory and the EasyFlash then behaving like an original “Ocean module”. In the development phase, additional module formats were implemented so that an EasyFlash can correctly emulate almost all types of game modules. The EasyFlash has a 1 MB flash memory that is written to using the C64 and floppy disk drive or larger mass storage devices. As a result, software (EasyLoader) was developed, which enables any programs or module copies for the C64 to be written to the flash memory and selected via a start menu. In consideration of these possibilities, many game titles have meanwhile been converted to the EasyFlash, so that the disk loading times are no longer necessary and there is even the possibility of saving the scores on the EasyFlash. The implementation of “Prince of Persia” for the C64 is based on the Easyflash.

256 KB EPROM card for the C64

EPROM cards

These cards allowed direct access to one or more EPROMs for calling up permanently stored programs and were mostly electronically switchable.

Expansion card for IDE drives, CD-ROMs and CompactFlash cards for the C64.

Mass storage

In the 1990s, CMD developed new floppy disk drives with a storage capacity of up to 2880 kB. In the late 1990s, tech-savvy hobbyists developed an IDE interface. Additional devices such as CD-ROM drives or Compact Flash cards can be operated both on the IDE interface and on the SCSI hard disk. The two drives CBM D9060 and CBM D9090 were the only IEEE-488 hard disks that were manufactured by Commodore for the PET and CBM 8-bit computers.


The MMC64 is a plug-in module for the C64 that enables the C64 to read and write MMC and SD memory cards. Programs can be loaded and executed directly from the memory card. However, programs cannot be written from the memory of the C64 to the SD card (or MM card). This means that the MMC64 cannot replace the Commodore Floppy 1541 as a storage medium for self-programmers. Loading and then saving only works with an old 1541. The MMC64 is therefore intended more for the execution (playback) of finished games (or your own programs). A game like this can be loaded in a few (milli-) seconds. In addition, there are numerous plugins that make it possible, for example, to create so-called diskette images from diskettes or to write them to diskette (always only as complete image files).

MP3 @ 64

The MP3 @ 64 is an MP3 module for the MMC64 .

The Final Cartridge 3 multifunctional cartridge connected via the expansion port
Reset button for retrofitting the C64. With the ASSY250469 board version, this only triggers a reset for the drives and printer connected to the IEC port, but not for the entire home computer as with older boards

Multifunction cartridges

They were very common. This is mainly due to the low loading speed of the 1541, which can be increased to 10 to 20 times the speed using software. It started with simple fast-charging cartridges, and other functions were quickly added, so that in the end cartridges such as The Final Cartridge 3 , Hypra Load II or Action Replay came up with a large number of functions. In addition to the fast charger, there are usually various BASIC extensions, function key assignments, freezer functions, print functions, machine language monitors and much more. One such cartridge is still manufactured and sold today: the MMC Replay . Like its (now discontinued) predecessor, the Retro Replay Cartridge, it is largely action-replay compatible and bugs have been eliminated. The module uses more highly integrated and more modern components and offers more memory, more functions and the option of ROM updates. In addition, the functionality of the (also discontinued) MMC64 has been integrated.

Relay cards

In order to use the C64 to control electronic hardware, various relay cards existed. These were mostly connected to the user port and thus enabled eight relays to be controlled.

Reset button

A plug-in module that made it possible to reset the C64 by pressing a key switch. The vast majority of programs written in machine code could only be exited by turning the computer off and on again. The same procedure had to be taken in the event of a crash; the simultaneous pressing of RUN/STOPand , which was actually intended for this, only rarely worked RESTORE. Excessive use of the on / off switch was not only annoying, it could also lead to defects.

Chess computer

There was a plug-in card for the C64, The Final Chesscard, which contained a complete computer with chess game software ( chess computer ), the C64 took over the display of the game and the entry of moves.

Memory expansion

It happened that the 64 KB main memory of the C64 was not sufficient for certain applications, so that numerous memory expansions were made, which were mostly connected to the expansion port. The REU (RAM Expansion Unit CBM1700, CBM1764 and CBM1750) was distributed by Commodore itself . All memory expansions for the C64 could only be used by software that was specially designed for this; that excluded most of the games. Additional memory expansions , mostly only supported by GEOS or a few special applications (e.g. Pagefox ), played only a subordinate role.

Teleclub decoder

So-called Teleclub decoders were sold as a kit . This meant that the rather simple encryption of the pay TV station Teleclub could be canceled.

Turbo cards / processor cards

There have been a few attempts to improve the performance of the C64 with the help of a faster processor. The first thing that came onto the market was the Turbo Process expansion from Roßmöller , which had a 65C02 processor with 4 MHz. The direct successor to this card was the Flash 8, with an 8 MHz fast 65816 CPU. Both cards are partially incompatible with existing software and, moreover, very unstable in operation, so that they only eke out a niche existence. Only the SuperCPU , an accelerator card based on a 65816 processor clocked at 20 MHz, was granted a certain degree of success. A processor card with a Z80 , which turned the C64 into a CP / M computer, was strongly promoted when the C64 was launched, but did not achieve a large one because of the very low CPU speed and poor compatibility with other CP / M computers Distribution. In particular, almost all commercial CP / M programs required a line length of 80 characters, which the C64 could not offer by default.


There were extensions with the help of which the C64 could read the teletext tables of the television stations.

Produced variants

There were 16 different versions of the C64 mainboard internally .

C64 (1982)

The C64 was initially produced in a beige “bread box” housing shape, initially with orange, then with dark brown function keys. Original versions with the orange function keys and the silver Commodore nameplate are among the rarities . A large part of the German production was assembled in the Commodore factory in Braunschweig .

Educator 64 (1982)

The Educator 64 is a special version of the C64 in a PET housing, it was primarily intended for schools. The model is also known as the "4064" or "PET 64". This version could be offered very cheaply, as repaired hardware from the complained C64 was used.

SX-64 / DX-64 (1984)

The SX-64 / DX-64 is a portable version of the C64 with one (SX-64) or two (DX-64) built-in 1541-compatible floppy disk drives and a built-in 5-inch color monitor. The computer was not 100% compatible, but you could use C64-ROMs instead of the slightly modified SX-64-ROMs. Due to the low sales figures, however, only a few devices were produced: around 9,000 units of the SX-64 and even fewer of the DX-64.

C64 Gold (1986)

The "Gold Edition" of the C64 had a gold-colored bread bin housing and was mounted on an acrylic plate with an emblem. The occasion was the one millionth C64 sold in Germany. The small series was produced in 1986 in a very small number of around 400 pieces, other sources give 1,000 pieces. At a celebration on December 5, 1986 in the BMW Museum in Munich, this C64 was given to important people within the company as well as journalists and dealers who had made a significant contribution to the success of the C64. The “Gold Edition”, specially made in Braunschweig, was then hand-labeled from number 1,000,000. This device is very rare and a sought-after collector's item.

C64C (1986)

The C64C model has a new, flatter case that is modeled on the case of the C64 successor, the C128 , and bears the label "Personal Computer". In addition, it is equipped with slightly redesigned, cost-reduced hardware - the motherboard is smaller. In Germany the C64C is often referred to as the "C64-II".

C64G (1987)

The C64G again has the old case shape ("bread box"), this time gray / beige with a light keyboard and a cost-reduced motherboard. The keyboard's graphic characters are shown on the top instead of the front of the keys. The G in the name stands for Germany, as the bread box shape was very popular in Germany and the customers wanted this model to be met.

Aldi-C64 (1988)

The Aldi-C64 is similar to the C64G. It was only available in Germany and was sold through discounters (for example the Aldi Group ). Due to the omission of the 12 V voltage regulator on the 250469 boards, the 64er magazine erroneously wrote that the new SID 8580 would only require 5 volts DC voltage. The 9 volt AC voltage would therefore no longer be needed and would be missing at the user port. This information was wrong. In addition to the 5 volts direct voltage, the new SID 8580 also required 9 volts direct voltage, which was generated from the 9 volts alternating voltage. The 9 volt AC voltage was also required for the clock signal (50 Hz) of the two CIA real-time clocks and for the motor control of the datasette. The new, flatter housings and highly integrated circuit boards were unpopular with hobbyists because they were no longer compatible with internal extensions from third-party manufacturers.

C64GS (1990)

Commodore 64 Games System
Manufacturer Commodore
Type Stationary game console
generation 3rd generation / 8-bit era
world 1987
Main processor MOS Technology 8500
Graphics processor MOS Technology VIC II
Storage media Cartridge
Controller joystick

The Commodore 64 GS (GS = Games System) is a C64 released in 1987 as a game console . It was an attempt to establish the Commodore brand on the console market as well. It had no keyboard and no connection for datasette and floppy disk drives. Games could only be loaded via modules . The module bay was on the top of the device. The C64 GS was just as expensive as a full-fledged C64, which is why the C64 GS flopped. The model C64GS was officially only sold in England.

Predecessor and successor

Successor model Commodore 128 (1985) designed as keyboard computer

The predecessor of the C64 was the color-capable VC 20 , which was brought to market in 1981 and of which over a million copies were sold for the first time in the history of microcomputers. As the official successor to the C64, the Commodore 128 was brought onto the market in 1985 , which, in addition to its own C128 mode, had a C64 and a CP / M mode. However, due to unsatisfactory sales figures and high production costs, production of the successor model was stopped as early as 1989, five years before the end of production of the C64.

The models of the Commodore 264 series, the C16 , C116 and Plus / 4 , manufactured from 1984 onwards , were also unable to establish themselves on the market due to their incompatibility with the popular C64 and certain technical deficits. Production was discontinued in the same year and the remaining devices were sold at low prices. As a late successor to the C64, Commodore developed the Commodore 65 , which, however, was never mass-produced because the very successful Amiga 500 with the C65 did not want to compete.

The entry-level models of the Amiga series manufactured by Commodore , especially the Amiga 500 , were keyboard computers and enjoyed a similar popularity as high-performance game computers like the C64 at the end of the 1980s, but they were never able to oust the C64 from the market. Technically the Amiga was superior to the C64, but it also had completely different and more modern hardware.

Commodore International had to file for bankruptcy on April 29, 1994. At the same time as the manufacturer Commodore, the last home computer, the C64, disappeared from the market.

Replicas and further developments

During the 8-bit era, unlike many competing models, there were no legal or illegal copies of the C64 by other companies. The many special chips in the C64, which were only manufactured by Commodore itself or by its subsidiary MOS Technology and which were not sold to potential replicas, prevented this.

In 1998 appeared by the Belgian company Web Computers International of , a PC-compatible computer with Microsoft Windows 3.1 and preinstalled C64 emulator. Herz was an AMD microprocessor based on 486 (66 MHz), plus 32 MiByte RAM and 32 MiByte ROM. The was also equipped with a web browser ( Netscape Navigator ), a word processing program ( Lotus AmiPro ) and a spreadsheet ( Lotus 1-2-3 ). As with the original C64, the entire computer was in the same housing as the keyboard. The production of the unsuccessful model was stopped relatively quickly. This may have had something to do with the fact that the device did not have nearly the necessary processor speed to emulate a C64 in real time.


Jeri Ellsworth and Individual Computers developed the C-One or Commodore One as a replica of the C64 and reproduced the hardware using FPGAs . The first boards were delivered in 2003.

C64 Stick / C64 DTV

At the end of 2004 the English company The Toy: Lobster Company brought out the C64 Stick - also known as C64 DTV ( Direct To TV ) - which was also released in Germany. The design also comes from Jeri Ellsworth, it is essentially a C-One reduced to the bare essentials. It is a C64 replica in the form of the Competition Pro joystick with 30 built-in games (including Summer Games , California Games , Pitstop , Super Cycle and Uridium ). The connection is made directly to the television set. Those who are talented in soldering and those with a technical knowledge can expand the joystick with additional joystick ports as well as a PS / 2 port for keyboard, IEC port for printer and floppy disk drives and a socket for power connection. There are NTSC (since 12/2004) and PAL versions (since 8/2005).

Commodore 64x

In August 2010, Commodore USA published the news that it had acquired the worldwide license rights for previous Commodore brands, in particular for the C64 and the Amiga computer. In December 2010 a PC system called the Commodore 64 was announced in a true-to-the-original retro case. The basis is a mainboard with an Intel Atom D525 dual core chip, nVidia ION2 graphics, USB ports, card reader and optional DVD or BluRay drive. The computer was delivered with the operating system Ubuntu version 10.10. Later, with Commodore OS , it received its own operating system and an integrated C64 emulator .

Chameleon 64

The Chameleon 64 is a module developed by Individual Computers that appeared in 2013. It contains, among other things, a VGA port, PS / 2 connections for mouse and keyboard and a slot for SD cards . There are basically two operating modes available:

  • plugged into the expansion port of the C64 or SX-64
  • self-sufficient with an optional docking station that allows the connection of C64 keyboards and up to four joysticks.

If the module is operated on the C64, it offers a VGA output, VC-1541-compatible floppy emulation of two floppy drives, the emulation of REU, GeoRAM and various application and game modules. In stand-alone operation, the functions of a C64 implemented using an FPGA are also available. The module also offers a clock port for connecting a network card of the type RR-Net Mk2 or Mk3, which can be accommodated in the module housing.

C64 reloaded

First model

On April 1, 2014, individual Computers announced that they would be producing new C64 mainboards under the name C64 reloaded . The circuit board design largely followed the original circuit diagram with the Commodore number 250466. However, there are also deviations from the circuit diagram. So zero force sockets were installed and a 12V DC-DC converter technology was introduced. Instead of a TV modulator, an S-Video output and a 3.5mm audio jack socket were installed. The C64 reloaded can be switched from PAL to NTSC video standard without soldering. The C64 Reloaded also needs original chips for operation, which can be taken from defective C64 computers. This model was sold without the brand name Commodore . The sales start of the C64 reloaded was on May 20th, 2015. These boards sold out quickly.

Second model

The C64 reloaded MK2 is the first board in the series which is sold under the brand name Commodore. In contrast to the first model, the MK2 automatically detects the installed chip versions and configures itself accordingly. The sales start is planned for November 21, 2017. [outdated]

TheC64 Mini

In 2017 it was announced that the British Retro Games Ltd. and the Austrian Koch Media will launch a fully licensed mini version of the C64 under the name TheC64 Mini in early 2018. The device itself is based on the design of the C64, but is only half the size. The keyboard of the TheC64 Mini is a dummy. It has an HDMI port for modern televisions and monitors. The joystick supplied is connected to the device via a USB port. A USB keyboard can also be connected to the device, making it possible to write your own basic programs on the TheC64 mini . The device is delivered with 64 preinstalled games.


In December 2019, a device was finally brought onto the market under the name TheC64 that has the original bread box housing and, unlike the Mini, is equipped with a functioning keyboard. The hardware specifications are otherwise essentially the same as those of the TheC64 Mini. In contrast to the Mini, however, the computer can also be started directly with Commodore Basic.

Case for the C64C

In August 2016 it became known that individual Computers (icomp) had acquired the original molds for the C64C case in addition to the license for the brand name Commodore and intended to use them to produce new cases. On August 22, 2017, the housing was presented to the public at Gamescom and has already been sold; Regular sales started on September 1, 2017. The new cases are available in four colors: Original Beige, Classic Bread Bin, SX-64 Style and Black Edition. Since almost all C64 boards are identical in structure and there are only minor deviations from the C64C board, other C64 versions can also be installed in the case. This also applies to the models of the C64 reloaded .


Application software

Although the C64 was often referred to as a “game computer” and “daddel box”, as the majority of the software were games, many “serious” programs were also produced for the device - also because of its high hardware properties for the time. In addition to Office programs such as the word processing Vizawrite or Textomat and the Microsoft Multiplan and SuperCalc spreadsheets , there were a large number of programs for all conceivable applications, of which only a few from the German area are mentioned here: For graphic applications there were programs such as Hi-Eddi (for HiRes graphics) designed by Hans Haberl, Amica Paint by Oliver Stiller for multicolor graphics and GIGA-CAD by Stefan Vilsmeier for 3D models. The desktop publishing programs Printfox and Pagefox were also by Hans Haberl and published by Scanntronik . The latter was developed as a plug-in module and contained an additional memory expansion in order to be able to hold fonts, graphics and text for a whole A4 page in memory. All the usual layout functions were available, including special functions such as kerning .


Fischertechnik Computing

A number of learning programs were also produced for the C64, even though it was not a typical computer that was used in school lessons. The Apple II and its clones were particularly widespread here.

In addition to learning programs such as vocabulary trainers, math courses and programs for learning chemistry, hardware extensions were also offered, with which students could learn the basics of robotics, for example with the Fischertechnik interface 30562 for the C64 / VC20 . The C64 could also be used for learning and research purposes. In the 1980s, for example, the device appeared in many entries in the Jugend forscht competition as part of the test set-ups.

Programs for the C64 were also used in aviation. For example, US pilots were able to do instrument flight rules (IFR) flights with Bruce Artwick's Flight Simulator II , which were counted towards the extension of the pilot's license. The German counterpart was Uwe Schwesig's Flight Teacher , who offered an introduction to flying.


In 1986 the operating system GEOS (Graphic Environment Operating System) with graphical user interface ( GUI ) was offered for the C64. It was published in several versions and contained a large number of application programs. This graphical user interface greatly expanded the scope of the C64. This had become necessary because from the mid-1980s onwards, graphic interfaces were used more and more frequently as standard equipment in home computers, for example in the Commodore Amiga , the Apple Macintosh or the Atari ST . GEOS is maintained and expanded on various platforms to this day (as of 2005). However, it is very resource-intensive, so that most of the GEOS users also have modern hardware such as large memory expansions, super CPUs or hard disks.

In addition, a Unix derivative called LUnix was developed for the C64 . The Unix-oriented Wings operating system for the C64 is currently being further developed .

New C64 software and C64 hardware are still sold and developed by various companies (for example Protovision ).

Programming languages

The most important programming languages ​​for the C64 were the built-in BASIC and assembler . There was also a variety of programming languages ​​and dialects for the C64:

Flashing "Ready" start screen of the C64. As the top line of the screen shows, an interpreter for the BASIC programming language has been started automatically and is now awaiting user input.
Excerpt from a basic listing for the C64. The inverse characters are control codes, mostly for cursor, screen and color instructions.


The built-in Commodore BASIC V2 does not offer any commands to comfortably address the graphics and sound options of the C64, as these were not yet available on the VC20, from which the code was taken. The already existing and better BASIC 4.0 of the newer PETs was not used with the C64, because the PETs were not to be competed internally. The hardware - including video and sound chips - can be accessed directly via the BASIC commands PEEKand POKEB. also enables the programming of sprites in Basic. Furthermore, SYSsystem routines can be jumped to directly with the command: For example, causes SYS 64738a reset of the C64. Sound and graphics can only be maximized in assembler . More comfortable graphics and sound programming is possible with extended BASIC variants such as Simons' BASIC , which, however, were not part of the scope of delivery. Games for the C64 are therefore almost exclusively programmed in assembler. With later BASIC versions, for example the BASIC 3.5 of the C16 and Plus4 , the command set is considerably more extensive.

In addition to the built-in Commodore BASIC V2, there were also various dialects and compilers. A selection:


Austrospeed is a 2-pass compiler (3-pass compiler in overlay mode) that translates BASIC V2.0 code into a compact, quickly interpretable intermediate code (similar to P-code ). Programs compiled in this way run three to five times faster than uncompiled programs. There was also an associated decompiler for the Austrospeed .

Basic-Boss BASIC compiler

Basic-Boss is a BASIC compiler from Markt & Technik Verlag , which appeared in 1988 and generates very stable program results from pure BASIC programs. Pure BASIC programmers can use the compiler to get fast programs without having to resort to assembler. The user has to build certain “definitions” into his BASIC program, which then enable these high speeds after compiling. In very favorable cases, the programs run 50 to 100 times faster.


For the C64 there was a Bascoder for the BASIC dialect BASICODE . This was a cross-computer BASIC standard.

Exbasic Level II BASIC

Exbasic Level II is an extended and improved BASIC for the C64, which was loaded from floppy disk or installed by cartridge. In contrast to Simons' Basic, Exbasic Level II was not originally written for the C64, so that not all possibilities of the hardware of this computer were used by this BASIC extension.


G-Basic provided extensive programming functions that the standard BASIC of the C64 did not have. It was delivered as a hardware extension, the shape and size of which was reminiscent of a cigarette packet. This had its own reset button , as the C64 did not have one ex works.


Geo-Basic is a BASIC under the GEOS graphical user interface . However, it contained a lot of bugs and ran slowly, which is why it could not prevail. The main memory available for the application programs was also very small.


Petspeed is a compiler for the built-in BASIC V2.0 from Commodore; for longer programs the compiler needed a - rarely available - double floppy drive.

Simons' basic

Simons' Basic is a greatly expanded BASIC with graphic functions (circle, ellipse) and partially structured programming. Distributed on diskette or cartridge.


Assembler is the most important and - together with the built-in BASIC - the most frequently used programming language for the C64. The capabilities of the device could only be used optimally with assembler. There were different assembler development environments , the best known were TurboAss, Hypra-Ass and Giga-Ass. Cross assembler systems were used for large projects. These consisted of two computers that were connected with a data cable: A C64, on which the newly developed program was tested, and a second computer, for example another C64, an Amiga or PC, on which the source text was written and from a Cross -Assembler was translated. This made programming much more convenient, since the entire memory, except for the few bytes, was available for the transfer routine on the test C64 and the source code and assembler were not deleted in the event of a crash. However, a simple machine language monitor was enough to develop software for the C64: The best-known example of such a program was the Smon . Many expansion modules, such as the Action Replay or the Final Cartridge , also brought their own machine language monitors.


With Oxford Pascal there was a Pascal implementation that was able to write independent programs on floppy disk or to keep them in memory. It was completely standard-compliant. Also of UCSD Pascal , there was a port on the C64; however, it was so cumbersome and slow that it was irrelevant in practice.

There was also the book "Pascal with the C64" from Markt & Technik , which contained a Pascal development system.


In addition to the languages ​​mentioned, there are other programming languages ​​that are rather exotic. There is a C compiler (which, however, only implements a subset of C), Forth and COMAL are also represented; a COBOL implementation was even produced. There is also a logo for the C64.

There is also the Contiki operating system , which allows an Internet and Ethernet connection via the C64.

Today, cc65 is a powerful cross-compiler for the C language that covers almost the entire ANSI standard with the exception of floating point numbers . The compiler itself runs on most modern platforms.


The games for the C64 were one of the best selling points for the computer: Almost every known computer game in the 1980s and partly in the 1990s was implemented for the C64, including many arcade games , including Donkey Kong and Pac-Man . Estimates assume around 17,000 commercial game titles for this device, not counting the countless games that C64 owners programmed themselves. Over 95 percent of all games have a resolution of 160 × 200 double-width pixels.

Over the years, the games in particular have become more complex and graphically more demanding. Some graphical highlights for the C64 include the strategy game Defender of the Crown or Manfred Trenz 'action game Turrican II: The Final Fight , the graphics of which come close to Amiga quality. Other outstanding examples are Wizball (frame sprites), Stunt Car Racer (3D graphics with filled in polygons) or the Last Ninja trilogy. The presentation and animation of the popular sports games from Epyx / USGold ( Summer Games 1 + 2, Winter Games , California Games and so on) were also convincing. The Great Giana Sisters , inspired by Nintendo's Mario series , also enjoyed great popularity.


As early as the 1980s, political groups tried out the possibility of using computer games for their own purposes. These technically primitive games, which were exchanged as copies in school playgrounds, are mostly based on the technology of the C64, for example the right-wing extremist game "Anti-Turks Test" programmed by a 17-year-old , in which racist questions can be answered via the keyboard or the game “ concentration camp manager ”, in which a concentration camp must be run as effectively as possible. Many of these programs were indexed in the 1980s and early 1990s by the Federal Inspectorate for Media Harmful to Young People (at that time still the Federal Inspectorate for Writings Harmful to Young People, BPjS for short) and later confiscated nationwide by court orders.

Demo scene

The C64 contributed in particular to the development of a diverse subculture in which talented programmers developed tricks (for example the use of undocumented hardware functions, including a lot of tricks for the graphics chip) in order to circumvent the apparent limitations of the computer. Parts of this scene still live on today (see also demo scene ) or developed further into other computer systems such as Amiga or PC. The demo scene emerged from the cracker scene at the time in the 1980s . The intros, which were originally set as the opening credits for the purpose of presenting the skills and recognition of cracked games, steadily increased in complexity and were finally published as individual works ( demos ) without the associated cracked software.

The difficulties of this programming are often not revealed to an outsider because they cannot assess the complexity or the actual impossibility of the effect according to the specification. Some of the basic mechanisms concerned the use of the so-called raster line interrupt (interrupt triggering at a certain image line) integrated in the graphics chip to synchronize code sequences, the smooth scrolling of the screen area in both axes or the reuse of sprites within an image. Typical characteristics were above all rapid, dancing scrolls, simulated, horizontal cylinder shapes with 16 colors, as well as almost always a lavish acoustic accessory.

The demo scene explored the possibilities of the C64 furthest. Highlights were demos such as Deus Ex Machina by the Crest and Oxyron groups , Tower Power by the Camelot group , + H2K by the Plush group or Dutch Breeze by the Blackmail group, as well as Double Density by Mr.Cursor aka Ivo Herzeg, who is jointly responsible for the development of well-known PC Games like Far Cry is. The website of the demo group Alpha Flight 1970 contains some flash versions of typical productions. A huge repertoire of information on old and new productions is recorded in the Commodore 64 Scene Database (CSDb).

Pirated copies

With the rapid rise of the home computer in general in the 1980s and of the C64 in particular, a barter market for pirated software for this computer emerged. User software, too, but mostly games were exchanged between the C64 owners. This was very easy to do with the first commercial programs. However, the software industry soon tried to get the situation under control through various copy protection measures (using data carriers, paper-based queries or even runtime measures ). That hardly succeeded, as the scene almost simultaneously ensured that the software could be copied again with its own programs on the one hand, and unprotected versions were generated by decoding and targeted modification of the originals that could be duplicated with any copying program. A kind of "rabbit-and-hedgehog" race developed between the software industry and the C64 owners, in which new copy protection measures were to prevent the illegal distribution of software. Ultimately, however, almost every program for the C64 was sooner or later also in circulation as a "free" pirated copy.

Baron von Gravenreuth , a lawyer, initiated a first wave of warnings at the end of 1992 when he checked suspicious classified ads in computer magazines in which mostly private individuals advertised the so-called "Tanja letters" (under the pseudonym "Tanja Nolte-Berndel" and a few other women Pseudonyms). If someone so contacted responded to the alleged teenager's request to replace the software, he was warned, if necessary also reported, for a violation of copyright law. A few cases also led to house searches .

Over time it became the custom among crackers to put their own, more or less complex opening credits (a so-called “ crack trophy ”) in front of the programs they “cracked” . Typically, their own coolness was praised there in tickers, friendly cracker groups were greeted, and their own programming skills were increasingly displayed visually and acoustically. The demo scene described above first emerged from the independence of these cracker opening credits into independent programs, even if the demo scene was later clearly separated from the cracker scene.


A 6581 and an 8580 SID chip

The sound chip of the C64 was a sensation when the C64 went on sale, as there was no comparable home computer that offered such a variety of sound variations. Due to these technical possibilities, countless programmers set about using the C64 as a music computer and programming the corresponding music on it.

Particularly noteworthy for the German-speaking area is the piece "Shades" by Chris Hülsbeck , programmed completely on the C64 , who won the music competition of the specialist magazine 64'er with this song in 1986 and thus laid the foundation for his career in the field of game scoring. Other well-known C64 composers were Rob Hubbard , Martin Galway , Ben Daglish , David Dunn, Markus Schneider, Stefan Hartwig, Holger Gehrmann, Reyn Ouwehand, Jonathan Dunn, Matt Gray, Jeroen Tel, Jens-Christian Huus (JCH) and Charles Deenen ( Maniacs of Noise).

The professional music scene also used the C64 as a musical instrument. The musician and music producer Michael Cretu experimented with the sounds of the C64 in the 1980s, and Inga Rumpf's band also used the C64. Many musicians still claim to have got the first access to a synthesizer through the C64 , which was a basis of their later development. B. Rick J. Jordan from Scooter . In serious music , the C64 was used by Yehoshua Lakner , for example , and was consciously seen as a “historical musical instrument” with limited, but productive possibilities.

Mid-1980s came MIDI - sequencer and software. a. by the Hamburg company Steinberg (now the market leader with the product Cubase ), which used the C64 as a control center for MIDI synthesizers and MIDI samplers . With Steinberg's Pro 16 software , you could create professional pop music productions. The C64 was able to control 16 different instruments (piano, drums, bass, etc.) at the same time using a graphic display and manipulable numerical values. The clock rate and the memory of the C64 were completely sufficient to control MIDI instruments at will. The SID of the C64 was not used because the sounds only came from the peripheral devices. The C64 also gained a foothold in the film music scene (even if only briefly). For example, the 80-minute documentary about the notorious mutineers from the Bounty "Pitcairn - Endstation der Bounty" (director: Reinhard Stegen) was completely accompanied by music that was composed on a C64. The C64 thus fully demonstrated its suitability for use in the professional field. The Atari ST , which appeared shortly afterwards in the late 1980s, took over command of MIDI sequencing in almost all German music studios and replaced the C64 in the professional sector.


In Germany, various computer magazines especially for the C64 came onto the market from the early 1980s . The best known was the " 64'er " from the publisher " Markt & Technik ", the Heise-Verlag published the " Input 64 " a magazine on a data carrier (cassette and diskette). The disk magazines “ Magic Disk 64 ” and its offshoot “ Game On ” and “ RUN ” were also known and widespread . As the unofficial successor to the 64 series, the “ Go64! "( CSW-Verlag , Winnenden), which was absorbed into the" Retro ", which has been published quarterly since 2006. Furthermore, there are currently two German-language amateur print magazines, the " Lotek64 " (also available as a free PDF version on the World Wide Web) and the "Return". In England "Commodore Force" and "Commodore Format" were popular. Today there is still the English-language fan magazine "Commodore Free", which is also available free of charge as a PDF. Magazines such as Digital Talk , Mail Madness or the Australian diskmag Vandalism News also appear in more or less regular order on diskette . In addition to articles that can be read on the screen, these also contain the latest software, music and images.

Some of the magazines of the time that covered many different computer platforms (such as " Happy Computer ", " Power Play " and " ASM ") were initially very fixated on the C64 due to the market success of the C64, which owners of other computers often complained about.

The content of all these magazines was not only reporting on new hardware and software for the respective devices, but also the page-by-page printing of listings , i.e. program texts that the reader could then type into the computer by hand. This type of distribution of software for the C64 was often the only way for the owner to get programs, besides purchasing software or black copies, since the download from the Internet was not yet available.

The C64 in the GDR

From the end of 1985 the C64 was sold in the Intershop for “ Westgeld ” or forum checks , and other devices found their way to the GDR as gifts. Occasionally, thanks to Asian guest workers, the C64 could be bought as new goods in the state-organized second-hand goods trade ("A & V") for 8,000 marks . There was also private trade via classified ads . The used prices were 3000 to 6000 Marks for the C64 and up to 5000 Marks for a floppy disk drive. Recorded floppy disks and cassettes, however, were subject to the strictest import controls as data carriers, were also not allowed to be sent as gifts from the West and were therefore virtually unavailable without a relationship.


Today there are a number of Commodore 64 emulators , such as the VICE , the MESS , Power 64 (for Mac OS X and Mac OS 9 ), Frodo (among others for Symbian mobile phones, as well as Apple iOS and Android ) and the ccs64 . These allow C64 software to be run on more modern computers such as a Windows PC. In addition to disk images, the emulators can also use original C64 accessories such as B. floppy and data disk drives are controlled. In order to use the datasette or the original floppy disk drives, however, tinkering with cables is necessary in order to control the devices with today's ports. For users who do not like the long loading times of the C64, the emulators offer a virtual loading mode.

Most of the C64 software that was released in the 1980s can be used on today's systems (PC, Mac) with the help of these emulators . Since March 28, 2008, selected C64 games have been available in the download catalog of the Wii console.

The Internet Archive offers an emulator interface that can be used in the web browser with a large number of programs and games.


  • There is a (incorrect) BASIC expression which, instead of the due? TYPE MISMATCH ERROR, triggers a total system crash : PRINT 0+""+-0Enter and RETURNpress the key . As a result, the cursor disappears and there is no longer any reaction to any keystroke, even pressing simultaneously RUN/STOPand RESTOREno longer helps. An explanation that requires a little specific specialist knowledge can be found in the magazine "64er", issue 3/88, p. 73f.
  • Between the addresses $FFF6-$FFF9(decimal 65526 ​​to 65529) the sequence of letters "RRBY" is stored in the C64 kernal . These are the initials of the two main developers of the C64, Robert Russell and Bob Yannes .
  • According to a modern legend , there should be a certain address in the memory of the early models of the C64, which should cause a hardware defect if this address was loaded with a certain value. A certain diode on the circuit board should burn out and permanently disable the device. The command that allegedly triggered this was called " Killerpoke ". In reality there is no such command for the C64 - for the PET of the later series with 6545CRTC controller there was such a command, which led to damage to the integrated monitor.


Original literature from the Commodore company

  • Commodore 64 [MicroComputer Manual]. Commodore GmbH, AG and GmbH, Frankfurt / Basel / Vienna 1984, (PDF)


  • Boris Kretzinger: The box office hit: C64. In: Commodore - Rise and Fall of a Computer Giant: a short foray into the company's history with data, facts and the reasons why the computer pioneer failed in the end. Scriptorium-Verlag, Morschen 2005, ISBN 3-938199-04-0 , p. 35 f.
  • Christian Zahn , Boris Kretzinger, Enno Coners: The Commodore 64 . In: The Commodore Story. CSW-Verl., 2nd, revised. New edition. Winnenden 2012, ISBN 978-3-941287-35-8 , p. 40 f.
  • Brian Bagnall: The Commodore 64. In: People's computer: the story of Pet and VC-20, C64 and Amiga: rise and fall of the computer pioneer Commodore . Gameplan, Utting am Ammersee 2011, ISBN 978-3-00-023848-2 , p. 138 f.


  • Hans Riedl, Franz Quinke: Commodore 64. The computer for beginners and climbers. Data, text, graphics, music. Friedrich Kiehl Verlag, Ludwigshafen 1983, ISBN 3-470-80421-4 .
  • Celestine Lorenz: Rule the Commodore 64. Hofacker, Holzkirchen 1983, ISBN 3-88963-147-9 .
  • Mark Eckenwiler (Ed.): The Commodore 64 LOGO. Terrapin Inc. Cambridge 1983.
  • Tim Onosko: The Commodore 64 for hobby, school and work. Carl Hanser Verlag and Prentice Hall International, Munich / Vienna / London 1984, ISBN 3-446-14073-5 (Hanser) / ISBN 0-13-152232-9 (Prentice Hall)
  • Peter Diepold u. a .: Learning modules for the C 64. Westermann Schulbuchverlag, Braunschweig 1984, ISBN 3-14-508812-2 .
  • Raeto West: C-64 Computer Manual. te-wi, Munich 1985, ISBN 3-921803-24-1 .
  • Hans Lorenz Schneider, Werner Eberl: The C-64 professional manual. Market and technology, Haar near Munich 1985, ISBN 3-89090-110-7 .
  • Michael Angerhausen, Lothar Englisch, Klaus Gerits: 64 - Tips and Tricks - A treasure trove for the COMMODORE 64 user. Data Becker, Düsseldorf 1986, ISBN 3-89011-001-0 .
  • Hans Joachim Liesert: Peeks & Pokes for the Commodore 64. Data Becker, Düsseldorf 1986, ISBN 3-89011-032-0 .
  • Michael Angerhausen, Rolf Brückmann, Lothar Englisch, Klaus Gerits: 64 intern. Data Becker, Düsseldorf 1988, ISBN 3-89011-000-2 .
  • Florian Müller: C -64 - Tips, Tricks and Tools. Markt und Technik, Haar near Munich 1988, ISBN 3-89090-499-8 .
  • Martin Hecht: The great Commodore 64 book. Data Becker, Düsseldorf 1991, ISBN 3-89011-370-2 .
  • Jörg Allner, Kerstin Allner: Commodore C64. World champion of all classes. In: Computer classics: [the highlights from 30 years of home computers] . Data Becker, Düsseldorf 2003, ISBN 3-8158-2339-0 , p. 86 f.


  • Ekkehard Flögel: Hardware - Extension for the COMMODORE 64. W. Hofacker, Holzkirchen 1984, ISBN 3-88963-146-0 .
  • Uwe Gerlach: Hardware tinkering for the C 64, C 128: e. easy to understand Einf. In d. digital circuit technology; with many board layouts u. detailed DIY instructions for e. Speech output module; Radioactivity meter; 128 Kbyte EPROM card etc. Markt-u.-Technik-Verl., Haar near Munich, 1987 ISBN 3-89090-389-4


  • Cölestin Lorenz: Programming in machine language with the Commodore-64. Hofacker, 1984, ISBN 3-921682-70-3 .
  • Florian Matthes: Pascal with the C 64. Markt & Technik, Haar near Munich 1986, ISBN 3-89090-222-7 .
  • Everything about the C-64. Programming manual. With appendix to GEOS. Markt und Technik, Haar near Munich 1987, ISBN 3-89090-379-7 .
  • Ralf Gelfand, Jacques Felt, Michael Strauch: The Anti - Cracker - Book. For C64 and C128. Data Becker, Düsseldorf 1988, ISBN 3-89011-253-6 .
  • Frank Riemenschneider: C-64 / C-128: Everything about machine language. Markt und Technik, Haar near Munich 1988, ISBN 3-89090-571-4 .
  • Harald Horchler (Ed.): Assembler is not alchemy. Learn assembler on the C-64. Scriptorium-Verlag, Morschen 2004, ISBN 3-938199-01-6

Game programming

  • Rüdiger Linden: Homemade C64 super games. Data Becker, Düsseldorf 1985, ISBN 3-89011-087-8 .

Demo scene


  • Axel Plenge: The graphic book for COMMODORE 64. Data Becker, Düsseldorf 1985, ISBN 3-89011-011-8 .


  • Thomas Dachsel: The music book for COMMODORE 64. Data Becker, Düsseldorf 1984, ISBN 3-89011-012-6 .
  • James Vogel, Nevin B Scrimshaw, Tony Westermayr: Commodore 64 music book. Birkhäuser, 1984, ISBN 3-7643-1590-3 .



  • Rainer J. Brandenburg: Measuring and evaluating with the Commodore 64 computer. Dümmler, 1985, ISBN 3-427-42211-9 .


Web links

Commons : Commodore 64  - collection of pictures, videos and audio files

Individual evidence

  1. Grandiose Price for a Modest PC ( Memento from July 19, 2008 in the Internet Archive )
  2. a b How many Commodore 64 computers were really sold?
  3. ^ Konrad Lischka : Playground Computer: Culture, History and Aesthetics of Computer Games . Heise, Hannover 2002, p. 52.
  4. Baloui, Brückmann, English, Felt, Gelfand, Gerits, Krsnik: The new Commodore 64 internal book. 1st edition. Data Becker, 1990, ISBN 3-89011-307-9 , pp. 354f.
  5. Mouse Commodore 1351
  6. Commodore 1541 ,
  7. Koala Technologies KoalaPad Touch Tablet ,
  8. Paddles ,
  9. Handyscanner 64 Scanntronik ,
  10. EasyFlash
  11. CBM D9060 / D9090 in the Commodore Computer Online Museum
  12. Highest known serial number: 1,000,362 , on, accessed on December 25, 2016.
  13. Michael Brückner: True values ​​- Stone Age PCs can bring in hundreds of thousands of euros. November 12, 2011, online at , accessed December 25, 2016.
  14. ^ Boris Kretzinger: Commodore. The rise and fall of a computer giant. Scriptorium, Morschen 2005, p. 65.
  15. Anonymous: Commodore at CeBIT 94. In: Amiga Format. Volume 6, No. 5, 1994, p. 21.
  16. Web site , formerly Commodore USA, accessed on 15 January 2017th
  17. ^ Chameleon - Individual Computers. Individual Computers, 2016, accessed January 15, 2017 .
  18. C64 reloaded: new C64 mainboards
  19. Sales start of the C64 Reloaded - icomp - de. Individual Computers, May 20, 2015, accessed July 31, 2020 .
  20. a b Commodore back in Germany. Individual Computers, August 31, 2016, accessed July 31, 2020 .
  21. C64 Reloaded MK2 - icomp - de. Accessed July 31, 2020 .
  22. The rebirth of the best-selling home computer! In: Koch Media - Press Server Blog. September 29, 2017. Retrieved October 19, 2017 .
  23. "Maxi": Another new edition of the C64 is here ,
  24. TheC64 - The World's Best-Selling Home Computer - Re-reborn , (English)
  25. Forum64 - New C64C case in colorful! Contribution from user sign-set
  26. ^ Valentino Z .: Austrospeed Compiler - software details. In: Commodore Plus / 4 World. May 11, 2013, online at, accessed January 27, 2017.
  27. BASIC BOSS. This basic compiler makes your programs up to 100 times faster. ( Memento of February 2, 2017 in the Internet Archive ), 64 'special issue no.11. Markt & Technik Verlag, Haar near Munich 1988, online at, accessed on January 27, 2017 (PDF; 4.1 MB) .
  28. Basic Boss. From, accessed on January 27, 2017.
  29. The fastest basic compiler. In: 64 magazine. 02/1989, pp. 100-102.
  30. Exbasic Level 2. From, accessed January 27, 2017.
  31. Workshop Geo-Basic - programming your own applications. In: 64's special issue no. 59 , pp. 4-7.
  32. Pet Speed ​​64 , on, accessed on August 25, 2017.
  33. ^ Simons Basic. From, accessed on January 27, 2017.
  34. C64 assembler ,
  35. Hypra-Assembler - top class programming like the pros ,
  36. Description Hypra-Ass for C64 ,
  37. Pascal with the C64 and Pascal with the C128 ,
  38. Pascal with the C64 ,
  39. “The Internet is cheap, fast and clean. We love it ”- right-wing extremists discover the computer. ( Memento from June 3, 2016 in the Internet Archive ; PDF; 210 kB) Report on the connection between right-wing extremists and computers, p. 3, online at, accessed on January 31, 2017.
  40. Gerd Meissner: Nazi Auschwitz goods as a computer game. In: The Chaos Computer Book. Rowohlt Verlag, Reinbek 1988, ISBN 3-8052-0474-4 , pp. 227-231.
  41. Index lists. In: BPjS-Aktuell. Official bulletin of the Federal Inspectorate for Writings Harmful to Young Persons, Issue 2/1999, pp. 16–55, here: p. 52.
  42. “The Internet is cheap, fast and clean. We love it ”- right-wing extremists discover the computer. ( Memento from June 3, 2016 in the Internet Archive ; PDF; 210 kB) Report on the connection between right-wing extremists and computers, p. 4, online at, accessed on January 31, 2017.
  43. ^ Ivo-Jürgen Müller-Herzeg aka Ivo Herzeg. From Retrieved January 31, 2017.
  44. ^ The C-64 Scene Database. Accessed January 31, 2017 at
  45. ^ Obituary: Günter Freiherr von Gravenreuth. February 22, 2010, from, accessed January 31, 2017.
  46. Robotron instead of Apple: Small computers in the GDR , MDR time travel GDR
  47. Classic: Internet Archive offers thousands of playable C64 games - . ( [accessed on October 13, 2018]).