<!---->The Commodore CBM-II
series was a short-lived range of 8-bit personal computers
from Commodore Business Machines
, intended as a follow-on to the Commodore PET
series, released in 1982.
The CBM-II had two incarnations, the P series
(P = personal, or, home use) and the B series
(B = business use). The B series was available with a built-in monochrome monitor (hi-profile) with detached keyboard, and also as a single unit with built-in keyboard but no monitor (lo-profile). These machines were known as the "Porsche
PETs" for their unique styling.
The P series used the VIC-II
40-column color video chip like the C64. It also included two standard Atari
-style joystick ports. The 6509 CPU
ran at 1 MHz in the P series due to the use of the VIC-II chip.
The B series used a 6545 CRTC
video chip to give an 80-column "green screen
" monochrome output more suitable for word processing and other business use than the VIC-II's 40-column display. Most models have the Motorola 68B45 installed which is a pin compatible variant rather than the MOS 6545A1 2 MHz part. On the B series the 6509 CPU ran at 2 MHz.
Features common to both the P and B series included an MOS Technology 6509
CPU, an enhanced version of the venerable 6502
, that was capable of addressing up to 1 megabyte
via bank switching
(however, no CBM-II model came with more than 256 kilobytes
of RAM, 1/4 megabyte
). The sound chip was the 6581 SID
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