Commodore 16
The Commodore 16 , or C16 for short, is an eight-bit home computer from the Commodore company . It is a model from the Commodore 264 series and should replace the Commodore VC 20 as an entry-level computer.
history
The C16 was designed to compete against other computers from Timex Corporation, Mattel, and Texas Instruments in the sub-$ 100 segment. It was intended to be the successor to the successful VC 20 , because it was now technically obsolete. The then successful C64 with more RAM and better sound and graphics chips was not suitable for the lowest price segment. Sinclair's computers ( ZX80 / ZX81 / Spectrum 16k ) were cheaper than the VC 20, but didn't have the large typewriter keyboard. Jack Tramiel , founder of Commodore International Ltd., feared that some Japanese companies would try to enter the American market with very affordable home computers ( MSX ). The C16 was launched to give Commodore a strong foothold in the lower price segment. With the Atari 600XL, Atari also offered a home computer for the lower entry-level market, the bigger brother, the Atari 800XL , competed with the Commodore 64.
The C16 was announced in June 1984 and sold from 1985. At this point, Mattel and TI had withdrawn from the home computer market, Japanese companies then brought home computers to the market with the MSX computers, but these were also more in competition with the Commodore 64. In 1984, however, the home computers were rated at 64 KB RAM (C64, Atari 800XL, CPC 464 , MSX) already as an entry-level home computer, so that the C16 / C116 had not been promised any great success before.
Like the complete trio of the 264 series (C16, C116 and Plus / 4 ), the C16 was not a great success either. At first there were no noteworthy numbers of games and “real” applications.
Only through the position of “ Aldi’s first computer ” did he gain a certain fame in Germany and experience a small boom. It was originally a pure selling off of the remaining stocks. The computer was offered by Aldi together with a 1531 datasette drive and BASIC course software as a "BASIC learning package" for only 149 DM . After the complete batch was sold out within a few days and only in half of the (then) federal territory, copies had to be reproduced from remaining spare parts in order to meet the demand halfway. This small boom also made itself felt in the software market. Kingsoft was one of the German software companies that brought out some high-quality games and applications for the time and the very simple system .
The C16 / 116 was also very successful in some Eastern Bloc countries without their own home computer industry, particularly in Hungary. There only a few could afford the computers built in the GDR and the Soviet Union, and most western models were not even available. There, further stocks of the C16 and C116 were exported at very reasonable prices, simply to clear the warehouse without disposal costs, which triggered a small boom of its own. A number of unofficial conversions of popular C64 games to the C16 come from there.
After the C16 and the variants C116 and Plus 4 had found widespread use in several European countries, a little over 400 commercial games and around 100 commercial application programs were produced and marketed between 1983 and 1992. A separate system segment in the magazine market developed relatively early on, parallel to the prevailing Commodore 64/128 and Schneider CPC systems. "Compute mit" was at that time one of the leading computer magazines for Commodore computers, in issue 43/84 (1984) numerous variants of the Commodore 16 family were presented for the first time.
With the C16 / 116 / PLUS4 and later with the Amiga 600, Commodore competed for its own products without surpassing its predecessors in terms of performance.
The C16 contains an early example of an Easter egg : entering the command SYS 52650 displays the names of the developers F. Bowen, J. Cooper, B. Herd, T. Ryan . F. Bowen appears inverted, T. Ryan flashing. The lead electronics developer Bil Herd was later also responsible for the development of the more successful Commodore 128 .
casing
Externally, the C16 is similar to the VC 20 and the C64 (= "bread box housing"), but the color of the housing and keyboard has been changed: The original plan was for an anthracite-colored housing with a dark gray keypad and light gray function keys. Prototypes in this color were made from reworked C64 cases and pictures of these devices were u. a. Used for press photos and as a picture on the original packaging. In series production, the new color scheme was discarded and the external appearance was adapted to that of the Commodore 264 or Plus / 4: The housing was changed to black, the keypad in light gray and the function keys in dark gray. For later devices, the housing colors vary from anthracite gray matt to glossy black.
The keyboard layout of the C16 was partly different than that of the VC 20 and C64, so there were now four separate cursor control keys ( arrow keys ), while the RESTORE reset button was omitted in favor of a reset button on the side.
Unlike the C64, the C16 did not have a user port . The largest connection is the expansion port, to which the Commodore 1551 floppy drive was also connected. On the right side of the housing are
- Power connection (9 V DC, 1 A , inner pole negative, outer positive)
- On-off switch
- Reset button
- two eight-pin mini-DIN sockets for connecting joysticks (see below)
On the back of the housing are:
- serial bus connection ( CBM bus for connecting floppy drives 1541 , 1570 , 1571 or 1581 of the C64 or a serial printer, same socket as on the VC-20 and on the C64);
- a seven-pin mini-DIN socket for connecting the 1531 Datasette (see below);
- Audio / video output (DIN, eight-pin, same socket as on the C64) for connecting a monitor with composite or S-video input or a correspondingly equipped television set;
- HF output, for direct connection of PAL or NTSC television sets via their antenna socket (PAL sets use the UHF channel 36, 591.25 MHz );
- Expansion port, with a smaller socket than the expansion port of the C64 and also not electrically compatible with it.
Technical specifications
- Circuit board: There are a total of two versions of the main circuit board of the C16: On the one hand, the very compact double-sided circuit board used in the series devices, and on the other hand a considerably larger, but only one-sided designed circuit board (single layer), which is only built into the prototype of the C16 was. The construction of this circuit board was an extraordinary attempt on the part of Commodore to be able to save additional costs in the production of the C16, which, however, probably ultimately failed due to technical problems. Only one example of such a single-sided home computer circuit board from Commodore has survived worldwide.
- CPU: The CPU used in the C16 is an eight-bit MOS -7501 or -MOS-8501. Despite different names, the CPUs are identical, only the manufacturing process has been changed, so that MOS decided to make this recognizable by changing the name. As far as the official commands are concerned, the 7501 and 8501 CPUs are command compatible with the 6510 CPU of the C64. Due to the radically changed internal structure of the 264 series in contrast to the C64, it was hardly possible to capitalize on it. In the C16, the CPU also handles the control of the datasette and the serial bus via its built-in input / output port.
- Clock frequency: The C16 works with 885 kHz and 1.76 MHz. The TED chip generates the clock frequency and switches back and forth between these frequencies, depending on whether it also needs access to the bus. The TED works with the low frequency for graphics output and DRAM refresh and switches to the high frequency while the screen frame and the synchronous pulses are displayed. The average speed of the C16 is only about 1 MHz.
- RAM: The C16 was sold with 16 KB RAM , whereby under BASIC only 12,277 bytes (approx. 12 KB) were available. When the graphics mode is switched on, the free memory for BASIC programs is reduced to 2 KB. The maximum memory capacity of the C16 is 64 KB, so that by replacing the two µPD4416 DRAM chips (16 KB × 4) with pin-compatible µPD4464 DRAMs (64 KB × 4) and pulling two wire bridges (which are not associated address line of both address decoder to the corresponding port of each RAM chip) of the free BASIC memory can to 60,671 bytes about 60 KB) increase ((larger memory upgrade, for. example, 256 KB, can by realized by hobbyists bankswitching integrated solutions) . The last models already have the 4464 RAMs ex works due to the fact that production of the 4416 chips has been discontinued in the meantime, so that you only have to put the wire bridges. From a software point of view , the C16 expanded in this way is identical to the plus except for the missing ROM application software (3-Plus-1), the missing 6551 interface chip for the RS-232 interface and the eight-bit I / O chip MOS 6529 / 4 , therefore practically all Plus / 4 software except terminal programs ran on such a system. Some C-16 games could also use the additional memory, for example to display better graphics.
- Computers created under the management of Jack Tramiel
Sales start Surname DRAM accesses (ms) 1983 C64 2000 1984 C16 1760 1985 Atari ST 4000
- ROM: The 32 KB ROM of the C16 contains the BASIC 3.5 , a further developed BASIC 2.0 of the C64. There is an integrated machine language monitor in the ROM for this purpose , with the help of which programs can be debugged.
- TED chip: The 'Text EDitor' TED chip was manufactured by MOS under the designation MOS-7360. While different ICs were built into the C64 for graphics and sound output as well as the interface ( VIC-II , SID , 2 × CIA ), the TED was the all-rounder of the C16. The 48-pin DIL chip takes on the graphics output and generates the composite video signal. It generates the sound output, reads the keyboard and joystick inputs, contains three timers (two independent), generates the clock frequency of the C16, contains the memory interface and takes care of the DRAM refresh cycle. It can address the entire 64 KB address space of the C16 and generates the signals (RAS, CAS and MUX) required for memory access. With ROM access it addresses the correct Chip Select (CS) lines, depending on the status of the internal registers.
- Graphics: 320 × 200 with 121 colors. See TED for more details .
- Sound: mono, two voices with four octaves. One of the voices can only produce square waves, the other can produce square waves or noise. Volume can only be set in eight levels for both voices. Three-bit digital sound is possible. See TED for more details .
- Joystick: Commodore decided to deviate from the established de facto standard of the Atari 2600 and to install eight-pin mini-DIN sockets instead of the nine-pin D-Sub pin headers . Commodore itself only sold a single, but poor quality, joystick model for this connection, and none were available from other companies. The control logic differs only slightly, so that adapter cables soon became available for simple joysticks (without automatic fire, etc.). Unlike the C64, only joysticks can be connected to the joystick ports of the C16; the connection is unsuitable for paddles , light pens and mice . In contrast to the C64, the C16 hardware allows the keyboard and joysticks to be queried completely separately and without mutual interference; However, the built-in firmware does not make use of this possibility, so that even with the C16 nonsensical characters appear when you move the joystick at the BASIC prompt.
- Datasette interface: A Commodore 1531 datasette could be connected to this 300 baud interface . In contrast to the circuit board connector of the 1530 datasette of all previous Commodore computers, the 1531 had a round mini-DIN connector. However, the signals are identical, so adapters in both directions soon became available.
- Serial port: The 'Commodore Serial Bus' was a serial bus developed by Commodore. The C16 had the same CBM bus as the C64, so the serial printers and floppy drives (1541) of the C64 could also be operated on the C16, but they were just as slow.
- Expansion port: The C16 could be expanded by modules, these were then operated in this slot (although only very few appeared on the market). The faster floppy 1551 of the C16 was also operated via the expansion port. It was a bit unfortunate, however, that the expansion port was simply looped through the bulky connector of the 1551. If several 1551 were to be operated, the connectors first had to be plugged into each other and then into the expansion port. As a result, the C16 could not be operated on the edge of a table because the weight of the connectors placed too much mechanical stress on the expansion port.
The end of the 264 series
The complete 264 series had three major problems: With the exception of the Plus / 4, they had no user port , the programs were not compatible with the C64 and game programmers had the problem that the TED had no hardware support for sprites like the VIC-II of the C64. The BASIC interpreter, which was improved in contrast to the C64, also offered graphic functions, including shapes ; for game programming, which was usually done in assembler , this was irrelevant. In addition, the C64 with its SID was able to produce a significantly better sound than the TED.
The TED is often the cause of a defective computer. The TED often self-destructs due to the high level of heating during normal operation. Many owners have therefore retrofitted heat sinks and reduced the supply voltage of the entire computer to the lower end of the permissible voltage range. Plugging or unplugging cables from the joystick ports during operation can easily destroy the TED, as it is connected directly to the joystick ports without any additional protective circuitry.
The CPU in the C16, as it is connected to the serial port and the datasette connection without protection, can also be destroyed if cables are plugged in or unplugged from these ports during operation. Towards the end of production of the C16, a few protective diodes were added to the circuit to reduce the problem.
Commodore did not see the incompatibilities as a big problem, because after all, many owners of a VC-20 had switched to the successor C64, even though it was not compatible. However, there weren't many VC-20 users who could have been interested in the C16 in 1985, and the C16, which is poorer in most technical features, gave C64 owners no incentive to change, especially since there were already a huge number when the C16 was released of software for the C64 was available and the C16 did not have a user port for extensions like the C64. So the C16 and the entire 264 series were a flop.
Individual evidence
- ↑ TheLegacy.de Website: TheLegacy: a nostalgic game museum ( Memento of the original from June 8, 2015 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. . Retrieved June 14, 2015.
- ↑ Kultboy website: Cover: Compute with 43/84 - test reports, editors, scans, information, magazine . Retrieved June 14, 2015.
- ↑ a b Forum64.de: Detailed report on a Commodore 16 prototype . Retrieved May 26, 2019
- ↑ Commodore 264 Series Technical Page . Crossconnect.tripod.com. Retrieved June 6, 2010.
- ↑ Plus4world.com: Bil Herd: About the Commodore 16 prototype (English) . Retrieved December 27, 2017.
- ^ Heinz Nixdorf Museum Commodore 16 prototype . Retrieved December 12, 2018.
Web links
- Information and pictures about the C16 at computer collection vienna
- Commodore 16 information at Old-Computers.com (English)
- German Commodore 16 page
- Review C16 in Drean Commodore (Spanish)
- Detailed report about a Commodore 16 prototype
