The Tomy Pyuuta Mk II

Last modify 1 January 2007. Please contact me FIRST! before using any photographs from this page.

Photographs | Scans | Screenshots

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Photographs

Here's my Pyuuta Mk II, vintage 1984 (approximately). This machine was a chance find by my very good friend Hidehiko Ogata in Akihabara, Japan (along with a Commodore UltiMAX) and we were able to figure out a way to get it over to these shores -- again, many thanks! ^^

The Mark 2 just looks more professional than the Pyuuta or the Tutor (let alone the Jr) thanks to its improved keyboard that you actually have some prayer of typing on. The fact that it's all in English can't have endeared itself much to its target market, however.

Obviously, like the Pyuuta, this unit uses 100V 60Hz Japanese mains current for which step-down transformers are easily available (mine was $30 at Fry's). Once again, my sincerest warning: although it will work on USA mains voltage, doing so is probably a straightforward way of diminishing the mean lifetime of the computer's power supply. Don't risk it.

[Thumbnail portrait of the Mk II.]

Portrait of the Pyuuta Mark 2. Click the thumbnail for a larger view (90K).

The keyboard is much better (feels very much like the Tandy CoCo), and MON and MOD have been moved into somewhat more sensible places. Also check out the interesting cursor key quasi-diamond at the upper right. However, instead of providing two proper SHIFT keys (although the larger SHIFT key is definitely appreciated) and putting LOCK in an expected position above the leftmost one, the LOCK is where the right SHIFT ought to go in an obvious hazard to unwary touch-typists and there's still just one SHIFT key. Even with its improvements, it is still a rather inferior arrangement and no one would have ever dared use this computer to type up their term papers.

One thing is nice, though -- the Pyuuta Mk II does have lowercase.

[Thumbnail portrait #1 of the box.]

The Mk II box and logo, with the included set of disc controllers (just like those with the Pyuuta). Click the thumbnail for a larger view (84K).

[Thumbnail portrait #2 of the box.]

The front of the box demonstrates two of the game titles. Click the thumbnail for a larger view (93K).

[Thumbnail picture of the underside.]

The underside of the Mark 2. Click the thumbnail for a larger view (71K), or zoom in on the label (36K). I was initially mystified by why there is an FCC certification on a Japanese home computer, but it's there in English. However, the explanation is pretty simple: it's the same base and injection mould as used for the bottom of the USA Tomy Tutor. In fact, the FCC ID and FCC blurb text is exactly the same. I should also note, however, that there seems to be some tape residue on the sides of the FCC legend, so this may have originally been taped over. The only other difference is that there is no UL-listed sticker here (there is on the American Tutor).

So why didn't the Pyuuta Mk II just use the case mould from the original Pyuuta? Since Tomy was in full swing producing the American Tutor, I presume this was a cost-cutting decision to reduce the number of moulds in service.

Remove the screws and take the back cover off, giving us access to ...

[Thumbnail of the disassembled Mk II.]

... the interior of the unit. Notice how the keyboard easily comes off the top half (on mine it was not secured with anything), meaning much less trauma to the keyboard ribbon cable. The keyboard sits on plastic pegs coming up from the lower case. There is no Faraday cage in this unit, nor any heat sink clamps, and the wires to the power LED are much shorter (I had to pull the connector off [88K] to get this view -- be very careful to remember how it was originally on since obviously it only works in one direction).

Click the thumbnail for a larger view (110K).

[Thumbnail of the mainboard of the Mk II.]

A closeup on the mainboard revealing the major items. The yellow arrow indicates the 9918ANL, which is not heat-sinked in the Mark 2; the green indicates the 9995NL, purple the power connectors, cyan the power supply (here is a view of the power supply [68K]). The SN76489AN chip is at the top left of the Custom Logic Array. The single firmware chip is indicated by red.

Click the thumbnail for a larger view (244K).

There are some notable oddities about the Mk II motherboard. The first is the total absence of any composite video or audio out jacks; this system is RF or bust (30K). If you want, however, it should be possible to modify the Mk II for composite in the same way that the Pyuuta Jr. can be comp-modded.

The second has to do with the firmware. The red arrow indicates the single Pyuuta Mk II ROM, which is identical to the Tutor-1 ROM on the American Tutor board ("ROM 1" on the Hardware schematic), and announces the same firmware version (2.3). All is well; you get to the brag screen, and then to the menu, where you attempt to select BASIC ... and the machine crashes and restarts. The reason is that BASIC is in ROM 2, and there's no ROM 2 on this board, nor is there even a socket or empty solder pads where it might have gone.

It also seems that the cartridge ROM banking logic (see the Hardware page) that controls the presence of BASIC or cartridge ROM on the Tutor is not supported by the Custom Logic Array chips in the Pyuuta Mark 2. Indeed, the cartridge just seems to map right on in where BASIC would go. With a cartridge installed, if you select BASIC from the menu, the machine goes bananas and crashes hard after some of the most psychedelic graphics you've ever seen (presumably trying to execute GPL code out of the cartridge ROM which is actually full of 9995 assembly instead) -- but not all cartridges do that. Many of the second generation cartridges, especially those released in the American market, seem to have enough Tomy GPL in them to allow BASIC to start up and give you a READY prompt (and then it crashes with a flash of ERR 2 and a scrambled screen).

Now that you know all this, how can you put BASIC back into the Pyuuta mk II if it doesn't have a BASIC ROM? Well, since we know that the cartridge will map into BASIC's normal addressing range, we can just put BASIC in a cartridge. That in a nutshell is the BASIC-1 cartridge, which is required to use BASIC on the Mark 2 (see the Incomplete Catalogue). Note that because the American firmware in the Mk II doesn't know how to detect the presence of the BASIC-1 (since it assumes the ROM is there), it will let you select BASIC when you shouldn't.


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Scans

I am still searching for a manual for this unit. If you have one you're willing to part with or sell, or can make scans from, I would be eternally grateful.


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Screenshots

The Pyuuta Mark 2 firmware is identical to the American Tutor (save the absence of the BASIC ROM), but for the sake of completeness:

[Pyuuta-2 screen shot.]

The firmware version displayed onscreen by my Mk II (version 2.3) is also identical to my Tutors', as well.

Apologies for the RF interference; I blame the immense EMI generated by my Power Mac. ^^ This unit was not comp-modded since, being otherwise the same, there's really no point.


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