CBM PET 40xx / CBM 40xx series (1980)

Features

CPU: 6502 1 MHz
RAM: 16 or 32 KB
ROM: 20 KB
Text Modes: 40 columns x 25 lines, upgradeable to 80 columns
Graphic Modes: None
Colors: Monochrome
Sound: Programmable piezo buzzer
I/O Ports: IEEE 488, I/O ports (8), Tape (2)
Keyboard: QWERTY full-stroke keyboard
Built In Language: Commodore Basic 4.0

Usage

MESS emulates the following computers

cbm40 [Commodore 40xx FAT (CRTC, 60Hz)]
cbm40pal [Commodore 40xx FAT (CRTC, 50Hz)]
cbm40b [Commodore 40xx THIN (Business Keyboard)]

For each systems, MESS supports

two datasettes, using “cassette1” (cass1) and “cassette2” (cass2) devices, for tapes in .tap and .wav format (currently not working)
two cart slots, “cartridge1” (cart1) and “cartridge2” (cart2), for cart dumps in .crt, .a0 and .b0 format
two floppy drives, “floppydisk1” (flop1) and “floppydisk2” (flop2), for disk images in .d64 format.

Also notice that a “quickload” (quik) feature is available for .p00 and .prg files.

These systems require full keyboard emulation to work correctly. At startup, full keyboard emulation mode is enabled by default. Whilst in full keyboard emulation mode, some key associated functionality may be disabled (like the Esc key for EXIT). The keyboard emulation mode is toggled using the Scrl Lock key (by default).

Original Keyboard: QWERTY full-stroke keyboard

CRSR  STOP
    <-   1!   2"   3#   4$   5%   6&   7'   8(   9)   0     :*   -=   UP    L/R   RUN           7   8   9

                                                                        CRSR    DEL
    TAB    Q    W    E    R    T     Y    U    I    O    P    [    \    U/D    INST             4   5   6

	 SHIFT
ESC   LOCK   A    S    D    F     G     H    J    K    L   ;+    @     ]      RETURN            1   2   3

RVS                                                                                HOME
OFF   SHIFT     Z    X    C    V    B     N    M    ,<   .>   /?   SHIFT   REPEAT   CLR           0     .


                                   SPACEBAR

RAM options

Different RAM configurations are possible for these systems in MESS. You can switch between them, changing the -ramsize parameter. At command line, you simply have to add -ramsize ram_value, where ram_value can assume one of the following values

8k
16k
32k (default)

Known Issues

The emulation of these systems is Preliminary.

History and Trivia

These computers are new versions of the PET series. The main improvement was the new ROM version (v4.0) which offered new possibilities such as direct disk operation commands (DLOAD, DSAVE, COPY, HEADER, etc.) or the ability to repeat cursor control characters by holding down keys. Late models also had a larger screen (12'') than the 2001 computers.

The disk drives were “Intelligent”, which means that they were CPU driven (MOS 6502) and had internal RAM (4 KB) & ROM (16KB, which contained the DOS).

The 4032 and the 4016 were sold with an 80-column dot matrix printer (5×8 character matrix). This printer (4022) was an Epson printer with a Commodore name on it.

(info from old-computers.com)