Sord M5 Pro

Sord M5 PRO

Recently, I bought a quite rare Japanese homecomputer at Ebay. It is the M5 Pro variant of the less rare (but still rare) Sord M5 computer. As the M5 was sold also in Europe, there is some information available on it. However, the M5 Pro was sold only in Japan, so this post focuses on the differences of the M5 Pro to the M5. As we will see, we can get rid of some misconceptions that have been made on the M5 Pro and Jr.

Sord Computer Systems was founded on 15 April 1970 by Takayoshi Shiina. In its first ten years it had become one of Japan’s fastest growing firms thanks to its success selling business micros on its home turf. The word Sord was derived from ‘SOftware haRDware’.

In 1982, Sord introduced its homecomputer model “M5”. It was meant to be mainly used as a games console. Therefore, it featured two joystick ports, only 4 kB of RAM, 4-channel audio, 32 sprites, and a cartridge slot. Also typically for game machines, the Basic was not built-in, but was delivered as a cartridge. Even more revealing is that the delivered Basic, Basic-I (I for Integer) did not feature floating point numbers or graphics commands. If you wanted these features, you’d need a Basic-F, or a Basic-G cartridge, respectively. The design of the case was very slick, and the PCB design and its build was high-quality and clean. The machine contained a dedicated graphics and audio chip and used Static RAMs. The keyboard was of a ZX Spectrum quality (because, again, this is not a serious business machine, and a 4 kB Basic program can also be entered by a lower quality keyboard). The M5 was introduced in other markets in 1983 (see the “The Register” article in the references for an account of the (lack of) success on the British market). There are also “CGL” branded M5s because CGL was the distributor of Sord in the UK.

Because the M5 was not a success, subsequent M5 models were only released in Japan, and not much is known about them. When we look at what we find on some popular web pages about the M5 Pro and M5 Jr., we find:

  • “[…] M5 Turbo, a faster version with “at least” 64KB of Ram […]. The M5 Turbo […] appear to have been released in Japan – as the M5 Pro […]” (The Register)
  • “M5 Pro […] were released with a built-in power supply unit (and more RAM?)” (old-computers.com)
    As we will see, most of that is basically not true.

What is true is that the M5 Pro and the M5 Jr. were introduced in 1983, one year after the M5. They were sold only in Japan. The price of the M5 Pro was 39800 Yen, and the one of the M5 Jr. was 29800 Yen. At the same time, the price of the M5 was reduced in Japan to 49800 Yen.

The point which the above sources are missing is that the M5 Pro is not the extended version of the M5, but the cost-reduced version of the M5 with the same features in the same case (but a different color scheme). It is neither faster nor has it more RAM. Also no built-in power supply, but exactly the same external power supply as the M5.

The difference between the M5 Pro and the M5 is the PCB. The M5 Pro PCB (Revision M5C-1B) is smaller, and uses different RAM chips (HM6116P-4 instead of TMM2016). The RF box is not mounted on the PCB anymore, but resides in the case next to the PCB.

There is also a strange switch that can be altered between H and L. On the M5 Jr. this switch is called “CH”, so I assume you can switch the antenna channels here.

The feature-reduced version of the M5 (and M5 Pro) is the M5 Jr. The missing features seem to be

  • the printer port
  • the video port (RF is still available)
  • the audio port

Addditionally, the power supply finally is integrated into the case. The PCB again is different from the M5 Pro (Revision M2C-01A). The case is slightly changed and the joystick ports moved to the front (which makes so much sense for a games console). The price is 25% less than the M5 Pro.

Z80 CPU, Japanese home computer: is the M5 family MSX-compatible? Well, no. It is using the same graphics chip as MSX computers, and a similar (but not the same) audio chip. But M5s have not enough RAM to meet the MSX standard, and they do neither have the MSX BIOS nor the MSX Basic.

While researching the M5 family, I found that the M5 Pro and the M5 Jr. were also offered in Japan under a different brand, namely as two models (?? and 84S) of the “Sanno Primary Computer” family. There are also other computers sold under this brand, but as the cases look the same as in the Sord case, they are easy to recognise. The Japanese “Sanno Institute of Management” had as its mission to computerize the Japanese schools. This program was lead by the Sanno Institute of Business Administration.

There you have it. The M5 Pro and the M5 Jr. are Japanese-market-only cost-reduced version of the M5. They are quite rare.

Technical Data

Manufacturer: Sord
Model: M5 Pro
CPU: Z80A @ 3.58 Mhz
RAM: 4 kB + 16 kB Video RAM
ROM: 8 kB
Graphics: Up to 256 x 192 at 16 colors, 32 sprites
Audio: 3 channels with 8 octaves, 1 noise channel
Interfaces: Power, Tape, Parallel, 2 x Game Pads, Audio, Video, RF (NTSC), Cartridge
Dimensions: 262x185x35mm, 800 g.
Introduced in: 1983
Initial price: 39800 Yen

References

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