In the West, we often know astonishingly little about early Japanese computers, especially when they were not also sold in the Western world. One of these examples is the “Basic Master” family of 8-bit models produced by Hitachi from 1978 to 1985.
Being sold from 1978, the Hitachi Basic Master (MB6880) was the first real home computer in Japan (and the first one to use the term “personal computer” over there). Apart from early Western models (like the TRS-80) before the Basic Master, you could buy basically only single board systems like NEC’s TK-80. And as it was considered a niche household consumer device it was developed by the Yokohama-based TV Division, not Hitachi’s Computer Division (who did the “serious” computers).
Motorola 6800-based models
In contrast to most other home computers, the early Basic Master models used a Motorola 6800 CPU. The 6800 was Motorola’s first CPU, an 8-bit processor. Apart from the Hitachis, only the APF Imagination Machine used the 6800 (also the SWTPC 6800 and the MITS Altair 680 used this CPU, but these were not home computers in the classical sense).
The first model of the family is the Basic Master (Level 1), MB-6880.
It has a Hitachi version of the Motorola 6800 CPU running at a whopping 750 kHz. It features 4 kB of RAM and 8 kB of ROM containing Hitachis Level 1 Basic that offers only integers. It can display 32 x 24 characters in black and white and offers a 64 x 48 pixel resolution. The video output is either composite oder (Japan) NTSC. The only mass memory option is a 300 bps cassette interface. This model uses an external PSU. The initial price wass 188,000 Yen.
1979 the second model was released, the Basic Master Level 2, MB-6880L2.
The only difference to its successor is double the amount of RAM (8 kB), double the amount of ROM (16 kB) containing Hitachi’s Level 2 Basic (hence the name), now also offering floating point numbers. Also the initial price is significantly higher (228,000 Yen).
The successor to the Basic Master Level 2 is the Basic Master Level 2 II in 1980 (MB-6881).
This time the RAM amount is increased to 16 kB and the price dropped to 148,000 Yen.
The final model that uses the Motorola 6800 is the Basic Master Jr. (MB-6885) that was released in 1981.
It also offers 16 kB RAM, 16 kB ROM, and the Level 2 Basic. It is initially offered for 89,800 Yen and is considered to be an entry level model. In constrast to the other models described above it now has a dedicated VRAM allowing a resolution of 256×192 pixels monochrome, even if one cannot access it from Basic. The case now looks different and includes the PSU.
I recently bought this model and can now show you the inside:
As one can see my model has the ROM upgrade which adds another 2 kB ROM and probably increases the cassette speed to 1200 bps. The PCB is very cleanly designed and built and contains a lot of Hitachi chips (that’s the advantage of being a big Japanese electronics company with a lot of experience in manufacturing consumer electronics).
The interfaces on the back of the case are labelled in Japanese. These are (from left to right):
- Cassette
- Video 2
- Printer
- Video 1
- Expansion Port
Motorola 6809-based models
The models using the Motorola 6800 CPU were not the only branch of the Basic Master family. The first model of the other branch was released already in 1980. This branch used a Motorola 6809 8-bit processor which ran at 1 MHz. They used a completely different architecture than the 6800 models and featured a Microsoft Basic (called Level 3 Basic). Additionally, the 6809 models offered a resolution of 640×200 pixels or 320×400 pixels in 8 colors. The usage of Microsoft Basic and the graphics resolution modes influenced man other Japanese computer models at the time. Finally the case became much larger and offering 6 expansion slots, almost having an Apple II vibe.
The first model is the Basic Master Level 3 (MB-6890) (codename: Peach) released in 1980 and sold initially for 298,000 Yen.
It offers 32 kB RAM and 24 kB ROM. It was also the first personal computer to offer Japanese characters! This model was also sold in Australia.
The successor was the Basic Master Level 3 Mark 2 (MB-6891) released in 1982. It was sold for 198,000 Yen.
I did not reliably found out the difference between the Mark 2 and the Mark 1. Some sources say the Mark 2 would contain Chinese characters in ROM. Some English sources on this computer claim it used a Z80 CPU. This is, of course, wrong. It uses the same Motorola 6809 CPU as the predecessor and the successor model.
The final model of the 6809 branch is the 1983 Basic Master Level 3 Mark 5 (MB-6892). It was sold for 118,000 Yen.
The RAM increased to 64 kB.
Motorola 68B09-based models
After the first branch of the Basic Master family using 6800 CPUs, the second one using 6809 CPUs, there was a final, third branch using 68B09 CPUs (Hitachi HD68B09E, to be more exact). The difference between 6809s and 68B09s is that the latter can clock twice as fast (i.e. at 2 MHz).
This third branch are the S1 family of computers. Apart from the much faster CPU, they also featured a 1 MB address space, 48 kB RAM, 48 kB VRAM (that can also be used for storing Basic programs if not in use), and not only Level 3 Basic, but also S1 Basic (an extension to Level 3 Basic created by Hitachi itself).
The first models in 1984 were the MB-S1/10 and the MB-S1/20, the difference being that the MB-S1/20 has a Kanji (Chinese characters) ROM card.
The next models, also in 1984 were the MB-S1/30 and the MB-S1/40. Both have a 1 MB floppy disk drive and the latter having a 2nd floppy disk drive and again having the Kanji ROM card.
In 1985 we get the MB-S1/10AV with a Super Impose feature, 6 voices audio and 2 Atari-compliant joystick interfaces. We also get the S1/15 and the MB-S1/45 which are MB-S1/10 and MB-S1/40, respectively with an additional communication ROM card and a RS232C interface.
There is also a variant of the S1 called the Limelight Interfield Systems (JB-806E1-2) sold in 1985. As the Japanese Wikipedia page puts it: A model that has the same features as the MB-S1 released by Interfield Corporation. Although it may be considered as a compatible machine, the built-in FDD is 2D instead of 2HD, the cassette interface has the limitation that it can not be controlled from BASIC. Level 3 mode (mode B), ROM BASIC, image generator, RS-232C interface, and the joystick interface have been removed.
There was a final model called the “Basic Master 16000”. Despite its name, it was a PC-compatible machine that had nothing to do with the Basic Master family of computers.
In the Western world, all Basic Master models are very rare. In Japan, most models are still available in auctions from time to time for a, partially even reasonable, price. There, the S1 models seem to be the rarest of the family.
References
- https://ja.wikipedia.org/wiki/%E3%83%99%E3%83%BC%E3%82%B7%E3%83%83%E3%82%AF%E3%83%9E%E3%82%B9%E3%82%BF%E3%83%BC
- http://www4.airnet.ne.jp/mit/Musium/HITACHI/BMaster.html
- https://www.old-computers.com/museum/computer.asp?st=1&c=1
- http://kyucom.sblo.jp/article/182795649.html
- http://www7b.biglobe.ne.jp/~kyonsi/papa_hobby/micom/4daime.htm
Rare & Old Computers 