* CPU: CDP 1802 2 MHz
* RAM: 35 kb (up to 67 kb). 32 KB available for Basic programs
* ROM: 16 kb
* Text Modes: 40 columns x 24 lines. 64 upper case ASCII characters
* Graphic Modes: None, but 64 user programmable graphical characters
* Colors: 8
* Sound: 1 channel synthesiser - 8 octaves, 16 volume steps and special effects
* I/O Ports: Tape, Monitor, 44-pin Bus expansion
* Keyboard: Calculator type keyboard, 55 keys QWERTY, Carriage Return (CR), RT, ESC, SHIFT (x2), DEL
* Built In Media: None
* Built In Language: Basic
* Peripherals: Printer, disk-drive
Currently, MESS supports two regional variations of the COMX 35
* comx35p [Comx World Operations Ltd. COMX 35 (PAL)]
* comx35n [Comx World Operations Ltd. COMX 35 (NTSC)]
Both drivers support the emulation of a "cassette" (cass) device, for tapes in .wav format, and up to two floppy drive, "floppydisk1" (flop1) and "floppydisk2" (flop2), for disk images in .img format.
Also notice that a “quickload” (quik) feature is available for .comx files and that the “printer” (prin) is emulated as well. Keyboard
This system requires 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 "Scroll Lock" key (by default). 80-columns
To enter 80-columns emulation, you have to mount the 80-column card in one of the slots and then to start the card. In order to do it, you can simply press TAB
while in partial keyboard emulation mode and enter the "Driver Configuration" submenu. Once you have selected the 80-column card in one of the slots (e.g. slot 3), you can go back to emulation by pressing TAB
and start the card by typing
Of course, if you have chosen a different slot "X", you will have to type "SX" in place of "S3". BIOS options
Different versions of the BASIC roms are supported. You can switch between them, changing the -bios parameter. At command line, for both comx35p and comx35n,
"-bios 0" or "-bios basic100" = COMX BASIC V1.00
"-bios 1" or "-bios default" = COMX BASIC V1.01 RAM options
Different RAM configurations are possible for the comx35p and comx35n 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
The sound emulation of these systems is known to be Imperfect.
History and Trivia
Very little is known about this obscure and rare computer.
It was desgined by a Netherlands based company called NOXON AB, and was manufactured in Hong Kong by COMX WORLD OPERATIONS LIMITED.
There is no graphic mode, but user definable characters can be used to simulate graphics. The sound features are poor as there is only one single channel beeper. You can hear it when pressing a key. The Basic is very simple, with not a lot of specific statements, since there is not much to play with...
The keyboard is said to be waterproof (can someone test that for us?) and used goldplated contacts under the keys (if you've got one, you are rich :-)). There is a built-in joystick to the right of the keyboard (very easy to break), a bit like on the Spectravideo SV-318. And just above it, is the power Led.
A small thermal printer was available for the COMX 35.
The chosen CPU, the RCA CPD-1802, was also used in the RCA Studio 2 videogame system and a development/hobby systems using Chip-8, like the Cosmac RCA VIP. This 8-bit processor is still being manufactured in many forms, as it is radiation-resistant. It was also used as the heart of the Voyager, Viking and Galileo probes !
The COMX-35 did have a successor: the COMX-PC1. This was just a COMX-35 in a different housing.
(info from old-computers.com)
* COMX Club Netherlands -- http://www.comxclub.hobby-site.com/COMX-Club.htm
* COMX 35 at old-computers.com -- http://old-computers.com/museum/computer.asp?c=110
* COMX Emulator -- http://www.comxclub.hobby-site.com/COMX-Club_Emulator.htm