The truth about V9948

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Par sd_snatcher

Prophet (3499)

Portrait de sd_snatcher

11-12-2011, 01:28

There are some speed differences between them. Those are described on the page 123 and 124 of the V9938 datasheet.

Par msxegor

Master (183)

Portrait de msxegor

11-12-2011, 09:25


V9938: YM2302, YM2302B and YM2302C

Are you sure about those numbers? YM23XX looks more like a sound synth part number
Checked two V9938's - both have 2701C number
Marking looks like this:

[MSX] V9938 YAMAHA
(c) 1984 アスキー
2701C (date code)

Par Manuel

Ascended (18710)

Portrait de Manuel

11-12-2011, 09:47

That V9938 datasheet says 2302 there... see page 134.

Par mars2000you

Enlighted (6179)

Portrait de mars2000you

19-12-2011, 12:08

VDP 9948 exists. The proof ? The new MRC website ! Wink

http://msxresources.files.wordpress.com/2011/11/v9948.jpg?w=...
 

 

 

Par gdx

Enlighted (5338)

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14-01-2014, 09:31

The v9948 is the VDP that would equip the MSX 3 (powered also with a Z280 CPU 16bit) but ASCII abandoned this project. The MSX2+ and MSX turbo R has been released instead in japan because there was a lot of users..

http://www.weblio.jp/content/MS-X

Quote:

MSX3

MSXはMSX2の次のバージョンはMSX2+、MSXturboRという規格名となり、MSX3が発表されることはなかった。しかし、アスキーにはMSX3の計画が存在していたことが、後に公開された資料や証言で明らかになっている。MSX2が発表された1985年前後には、Z80互換の16bitCPUのZ280、VDPはV9948、音源はMSX-AUDIO(Y8950)という内容でMSX3が計画されていたという資料が存在している[14]。別の証言では、コードネームはTryX、CPUはZ80互換の高速CPU、VDPにはV9978かV9998とナンバリングされたVDPが予定されていたが、VDPの開発の遅れから高速CPUであるR800のみがMSXturboRに搭載されたとされる

The V9948 is a protype.

Par Stt1

Hero (603)

Portrait de Stt1

23-01-2014, 14:06

I'll take my Captain off the shelf and take a look.

Par mars2000you

Enlighted (6179)

Portrait de mars2000you

23-01-2014, 15:06

The V99C37 is mentioned in this document :

http://archive.computerhistory.org/resources/access/text/201...

Quote:

Yamaha—An MSX personal computer CRT controller (V9938); CAPTAIN
videotex processing capability when combined with character transmission
display function CRT controller (V99C37) by ASCII Inc.; 400mW power
consumption; 100-pin, 4-sided flat package; 84-pin PLCC being studied;
sampling since July at ¥10,000 ($66.67)

So, this additionnal chip is conceived to make easy videotext with Japanese characters.

Precision found on many Japanese sites :

99C37は38用の26万色中256色表示用パレットコプロチップ。

99C37 is a palette coprocessor chip for the 256-color display in 260.000 colors for (99)38.

Par mars2000you

Enlighted (6179)

Portrait de mars2000you

23-01-2014, 19:41

Another precision found on a Japanese site

V99C37だな。
まぁ、実際はVDPの外部バスに繋ぐパレットレジスタだけどな。

It is V99C37.
Well, it is a palette register connected with the external bus of VDP in practice.

Par l_oliveira

Hero (533)

Portrait de l_oliveira

23-01-2014, 20:39

msxegor wrote:


V9938: YM2302, YM2302B and YM2302C

Are you sure about those numbers? YM23XX looks more like a sound synth part number
Checked two V9938's - both have 2701C number
Marking looks like this:

[MSX] V9938 YAMAHA
(c) 1984 アスキー
2701C (date code)

YM2302 = V9938 made at SHARP silicon foundry under Yamaha request.
YM2701 = V9938 made at HITACHI silicon foundry under Yamaha request.

Yamaha was a fab-less silicon developer. Their custom chips were developed in house then would be
made at Sharp, Hitachi or NEC. Similar to how KONAMI aways had their SCC chips being made at Toshiba.

Sharp V9938

Hitachi V9938

Hitachi HD64180 (Hitachi original design for Z180 MCU)

A Toshiba 68000 CPU in SDIP64 package:

And the SCC+

Par Stt1

Hero (603)

Portrait de Stt1

23-01-2014, 22:42

Normal V9938 on my Captain, just checked.

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