the link to the PDF doesn't work anymore... dakara dokuyaku shite miru koto ga dekinai kedo...

Does anyone know what kind of PSG is inside this MSX-ENGINE T9769? Is it an YM2149 type or an AY-3-8910?

http://ja.wikipedia.org/wiki/MSX-ENGINE

Following this Japanese page, it should be the AY-3-8910.

Hmm, but it doesn't mention the other MSX Engines. Maybe it just says "AY-3-8910 compatible"?

No, it mentions the 2 MSX-ENGINE produced by Toshiba (one for MSX1, one for MSX2 and higher) and the MSX-SYSTEM produced by Yamaha. I guess that the Yamaha engine uses the YM2149 (it should be logic), so it means that the MSX-ENGINE2 of Toshiba uses the AY-3-8910.

Here's the Excite translation :

MSX-ENGINE
Source: Free encyclopedia'Wikipedia (Wikipedia)'
Movement: Navigation, Retrieval

Custom-made chip MSX-ENGINE designed for MSX usage commercialized as home personal computer. There was T9769 for the usage since T7775 and MSX2 for the MSX1 corresponding, and Toshiba took charge of both manufacturing. CPU (Z80A equivalent goods) is built into these, and another chip named MSX-SYSTEM with built-in CPU exists, too. Yamaha Motor Co., Ltd. took charge of manufacturing here.
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Feature

T7775 MSX-ENGINE CMOS-LSI that condenses function of MSX1 to single-chip. The clock generator can be built into, and each mode of the RUN mode, the IDOL mode, and the HOLD mode, etc. be set from the program.

T9769 MSX-ENGINE2 The one that CPU (Z80 corresponding), PSG (AY-3-8910 corresponding), and circuit in surrounding necessary to compose MSX such as various ports and interfaces additionally were made single-chip. It was chiefly used with MSX2 and MSX2 + MSX turboR made by Matsushita Electric Industrial Co., Ltd. and made by SANYO Electric. 6MHz was able to be driven by cooperation with the custom-made chip of this company in MSX2 + made by Matsushita Electric Industrial Co., Ltd. though CPU was used by 3.58MHz drive. In turboR, S1990 was installed as system LSI besides this LSI, and exclusive control that CPU operation of considerable Z80A stops was done while operating R800.
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Location

The peripheral LSI named the logical circuit, 8255(PPI), and PSG that had had to compose of 74 series etc. was almost replaced with the single-chip by the appearance of integrated LSI like this chip so far, and it came to be able to manufacture MSX2 at a low price.

I think the "corresponding" means "compatible". Also, the fact that the Yamaha engine uses an YM2149 doesn't mean the Toshiba one should *not* use a YM2149!

Well, only Toshiba responsibles could give a definitive answer, but I guess there was such a competition between Toshiba and Yamaha to win some parts of the commercial market .... probably also some "agreements" between Yamaha, Philips and Sony on one side, between Toshiba, Panasonic and Sanyo on the other side. That's why I think the Toshiba MSX-ENGINE2 can't have a Yamaha PSG !