Tecnobytes V9990 Powergraph
This page was last modified 01:14, 11 December 2018 by Mars2000you. Based on work by Rderooy and Gdx and others.



The Tecnobytes V9990 Powergraph is a cartridge based on the Sunrise GFX9000, and can be used with all MSX computer generations. It is built around the Yamaha V9990 Video Display Processor. The V9990 is based on the never released Yamaha V9978 VDP (Video Display Processor), which was supposed to be used in the MSX3.

Compared to the Sunrise GFX9000, the V9990 Powergraph has the same specifications with the addition of NTSC composite video and S-VIDEO outputs. The RGB connector uses a male DE-15 subminiature connector instead.

Price: $125 + Shipping

Tecnobytes has also made a version smaller called the Powergraph Light. S-Video output is available with an adapter. Price: $89 + Shipping


Tecnobytes V9990 PowerGraph cartridge
Tecnobytes V9990 PowerGraph PCB
Tecnobytes V9990 PowerGraph Light with its S-Video adapter
Tecnobytes V9990 PowerGraph Light PCB


The V9990 Powergraph allows all Yamaha V9990 video capabilities to be used on MSX, and contains 512kB DPDRAM (dual ported dynamic RAM) memory. The video signal generated by the V9990 is available on all of its output connectors simultaneously, but just like the GFX9000 it still requires a second monitor for proper usage. One monitor connected to the MSX, and the other to the V9990 where video will only be shown when a V9990 enabled application is running.

Please check the Yamaha V9990 page for detailed information on its graphic capabilities.


The V9990 Powergraph is meant to be 100% compatible with the GFX9000, so any software written for it will work.


RGB out
CVBS out
S-Video out (requires adapter for the light version)

Pinout of the DE-15 connector

PowerGraph v1

The 1st version of the PowerGraph features a male DE-15 with a custom pinout

Pin Signal
1 R_out
2 G_out
3 B_out
4 V_sync_in
5 Csync_out
6 YS_out
7 DLCK_out
8 3.58MHZ_out
9 H_sync_in
10 Croma_out
11 Y_out
12 GND
13 H_sync_out
14 GND
15 GND

PowerGraph v2

The only difference of the 2nd version is that it features a DE-15 female VGA-15KHz connector.

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