CBM-500 series
The computer of Commodore from the CBM-500 series are designed to the end of the 1970s. They were intended as the successor to the successful "PET" computer ("Personal Electronic Transactor"). (The term "PC" / "Personal Computer" was not yet common knowledge at that time; it did not establish itself until 1981 with the IBM PC.)
technology
Like their predecessors and successors, the computers of the CBM 500 series were equipped with 8-bit microprocessors.
Within the CBM-500 series (CBM-II series) from Commodore , the P 500 was a model with a decidedly futuristic design. It came from Ira Velinsky , who also designed the prototype of the PET 2001 and the Atari Stacy , among other things . The CBM-500 series was an unsuccessful attempt to replace the PET / CBM series .
It was planned to build computers for private (P) and business customers (B). Like the C64 later, the P model was equipped with the VIC-II chip and was able to display 16 colors and up to 320 × 200 pixels. The B models were designed for everyday office life and could display 25 lines of 80 characters each with their MOS 6545 chip.
The P 500 was a keyboard computer for use with an external monitor. It was equipped with a MOS 6509 processor with 1 MHz. This processor was able to use bank switching to address up to 16 banks of 64 kB each. In contrast to the "B" models of the 600 and 700 series, this home computer had two joystick ports.
The P 500 was never officially on the market. Therefore, in contrast to its "brothers" of the 600 and 700 series, which were launched shortly afterwards, there is no software apart from a sales demo.
With easy to learn BASIC - programming language equipped, the computers of the CBM series were until the early 1990s important u. a. for controlling laboratory equipment and measuring devices , as they have an IEEE-488 interface. Even today they can still be found sporadically.
Models
The model numbers were assigned as follows depending on the memory allocation:
- CBM P500 (also C128-40 or P128 or PET-II) - 128 KB
- CBM B505 - 64 KB
- CBM B510 - 128 KB
- CBM B520 - 256 KB
