The following is an article I sent to old-computers.com but it never reached somehow the light of publication:
This extremely rare computer was designed as a successor of Tandy’s CoCo3 computer sporting OS/68k, but using a 68000-like Microprocessor. It came as a screw-it-together kit for a standard PC small tower case, bundled with Microware’s OS/68K, including a structed Basic, Emacs, and the C compiler, which was well beyond K&R but not quite ANSI. It used a 66470 VSC graphics chip developed for CDi. The MM/1 also has a backplane board (just a simple bus with a resistor pack or two and a couple header connectors) that connects the CPU board with the I/O board. The CPU board has floppy, video, keyboard, and a couple serial ports built in, along with 1M of RAM soldered onto the board that serves as system and video RAM. The I/O board added (I think potentially 3) more serial ports, two parallel ports, SCSI, RTC, 2 8-bit ADC/DAC chips for sound in/out (quite rare at the time), and joysticks, and up to 2M additional RAM in 30-pin SIMMs. There even was a MIDI interface as an option.
Somebody stated: “The MM/1 was always supplied as a kit (not much assembly required), to get around the FCC RFI limits. I can assure you that an MM/1 obliterates all hope of FM or TV reception in the same house!”.
Somewhere along the line, IMS sold the rights of the MM/1 to Blackhawk Enterprises (David Graham) in about 1994. Blackhawk sold remaining stock of IMS MM/1 equipment, and also had a redesign of the backplane and the I/O board. In this version, the backplane becomes a memory board that supports up to 2 4M 30-pin SIMMs. Memory is moved off the I/O board, and a later version of the SCSI chip is used.
But since there were problems with the Version 2 I/O board, David Graham also sold AT306 motherboards as the MM/1b while trying to work out the bugs in the SCSI interface of the original MM/1. The AT306 is a motherboard with a Motorola 68306 processor and an ISA bus so you could plug PC peripherals in and take advantage of cheap commodity hardware, if you could cook up drivers. Even though the hardware was very different from the original MM/1, David Graham called it the MM/1b because the licenses he had for OS-9/68K and the OS-9 Port Pack were valid “only for the MM/1”.
It is said that only between 200 and 500 of these machines have been made.
| NAME | Multi-Media One (MM/1) |
| MANUFACTURER | IMS |
| TYPE | Home Computer |
| ORIGIN | USA |
| YEAR | 1991 |
| END OF PRODUCTION | ? |
| KEYBOARD | ? |
| CPU | 68070 |
| SPEED | 15 Mhz |
| RAM | 3 MB |
| VRAM | ? |
| ROM | ? |
| TEXT MODES | ? |
| GRAPHIC MODES | 640 x 208,640 x 416 interlaced |
| COLORS | 8 bit |
| SOUND | Stereo Digital Audio in/out (8 bit) |
| SIZE / WEIGHT | ? / 11 Kg |
| I/O PORTS | Video, floppy, keyboard, stereo audio, SCSI, RTC, joysticks, 2 parallel ports, 4(?) serial ports |
| POWER SUPPLY | Internal power supply unit |
| PRICE | MM/1b Mainboard: $400 |
Links
- http://83.105.111.87/mjknudsen/cochist.html
- http://en.wikipedia.org/wiki/TRS-80_Color_Computer#Prototypes_and_rare_versions
Rare & Old Computers 