Tecnobytes V9990 Powergraph
This page was last modified 22:58, 29 May 2017 by Sd snatcher. Based on work by Tvalenca and Mars2000you and others.



The Tecnobytes V9990 Powergraph is a cartridge based on Sunrise GFX9000 for any generation of MSX computers, built around a Yamaha V9990 Video Display Processor. The V9990 is based on the never released Yamaha V9978 VDP (Video Display Processor), which was supposed to be in the MSX3.

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


Tecnobytes V9990 PowerGraph cartridge
Tecnobytes V9990 PowerGraph 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 only on every of its output connectors simultaneously, but likewise the GFX9000 it still requires a second monitor for proper usage.

Please check Yamaha V9990 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

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.