Introduced may 1981, the FM 8 was one of the first Fujitsu micro computers (after the LKIT-8 hobby computer in 1977). In any case it was the first member of the FM series, FM standing for "Fujitsu Micro". At that time its features were really impressive: bi-processor (even an additionnal Z80 cpu could be installed), 64 KB RAM, bubble memory, built-in chinese characters ROM, 640x200 high resolution with 8 colors and no proximity conflict!
The FM-8 was developed by employing innovative design and state-of-the-art semiconductor technology, and was designed for use in a variety of fields, ranging from high-level hobby use, to business applications and process control.
The Japanese Computer Museum specifies:
"The FM-8 had the following features:
- Equipped with two Motorola 6809 8-bit CPUs (main and sub)
- The world's first use of 64 kilobit DRAM (like that in large main frame computer) in a microcomputer (64 kilobyte main memory)
- Japanese language display using Chinese character (kanji) ROM (JIS level 1 2,965 characters, optional)
- High-resolution color graphics (640x200 dot, 8 colors selectable at each dot)
- The provided operating systems (OS) included F-BASIC, as well as UCSD-PASCAL, FLEX and CP/M (required Z80 card option)
- First use in a personal computer of bubble memory as external memory (At the time of announcement, the machine had a bubble cassette with a 32 kilobyte capacity. A 128 kilobyte cassette was added later. Bubble memory did not catch on, however, and was eliminated from the standard features in the FM-7.)"
When booted, a menu offers different choices:
1 - F-BASIC (ROM/DISK mode)
2 - DOS (mini- floppy disk)
3 - Bubble memory
4 - DOS (standard floppy disk)
There are a lot of character sets available (8x8 matrix): 69 alphanumeric char., 63 katakana signs and 62 graphic symbols. And for characters with a 16x16 pixels matrix: 2965 chinese characters (JIS standard level 1) and 453 non-chinese characters (JIS non-chinese characters).
Optional mini floppy disks could be connected (320 KB each), as well as an expansion unit which allowed many things (voice input/ouput, hard disk connection, RS232c interface, analog interface for measurement,etc.)
In November 1982, Fujitsu announced a upper model of the FM-8 called the FM-11, and a mass-market model called the FM-7.
Nomura, Hisayuki reports:
Fujitsu FM 8 / 7 have a very unique feature. They have 2 CPUs. 1 for Main CPU (it's usual) and 1 for Graphics. Graphic CPU has their own boot ROM and main program. The Graphic CPU recieves request from Main CPU and draw pictures with their software. The two CPUs share small part of memory area and uses this shared area exclusively.
In addition to Mr. Nomura's report. During game programmers there was famous "Hidden" feature.
The performance of FM-8 was not so excellent as many people expected. Dual CPU concept was bottleneck. When main CPU stores command code to shared memory, sub CPU get halt. Sub CPU restarts and start drawing. Problem was size of shared memory; 128 bytes are too small to store massive graphic requests. That is, FM series are not appropriate for hobby use.
However, One of BIOS programmer, Mr.Yamauchi in Fujitsu Ltd. left several hidden commands in sub-system BIOS, which is called YAMAUCHI command. These command permitted us to transfer large binary programs to reserved memory space and JMP! After unveiled this hacking technique, FM series are known to their performance in games.