The Toshiba T9769 is an MSX Engine with the following features:
- main CPU, a Zilog Z80 clone with a clock speed of 3,58 MHz (MSX2; switchable to 5,36 MHz on some MSX2+ machines)
- a Programmable Sound Generator - sound chip, compatible with a General Instrument AY-3-8910
- parallel I/O chip: backward compatible with the Intel i8255
- MSX1 and MSX2-functions (MSX2-computers)
- MSX2+-functions (MSX2+-computers)
- dimensions: 10,5 × 8,60 mm
This chip exists in four versions (T9769 and 3 revisions, labelled A, B and C), plus a prequel (T9763). As it is built, the table below has the advantage to clearly display the evolution in the using of the different chips.
PLEASE READ THIS BEFORE ASSUMING WRONG IDEAS ABOUT THE MSX2+ COMPUTERS: There have been several releases of the Panasonic and Sanyo MSX2+ computers and the chip used is not always the same, that's why 2 chips are indicated in the table below for these machines.
|Sakhr AX-370||-||-||x (1)||-||-|
|MSX Turbo R||Aucnet NIA-2001||-||-||-||-||x|
The differences between all the versions of the T9769 chip are not yet known, they could be related to problems with the TC8566AF disk drive controller and its evolution in Turbo R where the disk rom is 'merged' with the MSX-DOS2 rom. One difference is that the VDP I/O delay is different for these versions. For the C revision it is 1 cycle and for the others it is 2 cycles. See https://github.com/openMSX/openMSX/issues/563 and https://github.com/openMSX/openMSX/issues/989
On the Sanyo PHC-55FD2, the disk drive controller is not a TC8566AF from Toshiba, but a Western Digital 2793 (TMS2793NL). There are probably differences between the T9763 chip and its sequels.
An easy way to upgrade any computer using the T9769 chip to 512K RAM is:
- pull pins 51 and 52, connect to VCC (5V)
- Pull pin 50, mark as /CAS2
- Pull pin 47, mark as A8
Use 4x44256 chips and connect to the bus
More info: Tabajara Labs