MSX-Engine

An MSX-ENGINE chip is a specially developed integrated circuit for home computers that are built according to the MSX specifications. Generally, such a chip combines the functions of many separate, older/simpler chips into one. This is done to reduce required circuit board space, power consumption, and (most importantly) production costs for complete systems.

The first MSX-Engine chip, the T7775 operated next to a standard Zilog Z80-clone chip, the main CPU of the system, but later versions of the engine also included the CPU in a same single chip package, except for the last one, the S-1990, which also used an external CPU.

The T9769 is used in MSX 2 computers, while in MSX 1 computers mostly the T7775 and T7937 are used. You can also find the S-1985 and S-3527 in these systems. After the MSX 2 generation (from MSX2+ onwards) Toshiba took over the complete production of MSX engine chips. The last generation of MSX, the Turbo-R used the NEC S-1990 "TurboR bus controller" together with a R800 CPU.MSX engine chips from Yamaha were mostly used in MSX-computers from Sony and Philips, while the Toshiba chips were mostly used in computers from Sanyo and Matsushita (Panasonic/National).

Overview

Here is a short overview of MSX-Engine chips.

MSX 1

;S-3527

* a Yamaha YM2149 PSG-sound chip, compatible with a General Instrument AY-3-8910
* parallel I/O chip: backward compatible with the Intel i8255
* standard MSX1 functions: DRAM control, slot selection, joystick ports, cassette/printer interface etc.
* 100 pinsNote that this IC is also used in many MSX2 computers, but does "not" include any MSX2-specific functions. In such machines, these are implemented using additional IC's

;T7775
* CMOS-chip with all MSX 1 functions.

;T7937
* main CPU, a Zilog Z80 (clone) with a clock speed of 3,58 MHz.
* a PSG-sound chip, compatible with a General Instrument AY-3-8910
* Video Display Controller: Texas Instruments TMS9918
* parallel I/O chip: backward compatible with the Intel i8255
* MSX 1-functions
* dimensions: 10,5 × 8,60 mm

MSX 2/MSX 2+

;S-1985
* a Yamaha YM2149 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 (up to 512 KB memory mapper)
* Real Time Clock (Ricoh RP5C01A compatible) including 26 x 4 bits RAM, backed up by (separate) battery
* 100 pin flat plastic package

;T9769
* 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

MSX Turbo R

;S-1990 combined with a T9769C

"See S-1990 for the main article."

The S-1990 is not in itself an MSX-engine but acts like "bus controller", it is the combining element that combines the Z80 inside the T9769C (the actual MSX engine) and a R800 CPU, and the memory and slot logic and other hardware inside the T9769C. It also contains hardware to assists in the debugging of software.

External links

* [http://msx.retro8bits.com/msxdocs/s3527datasheetenglish.pdf s3527 Datasheet]
* [http://msx.retro8bits.com/msxdocs/chipss3527sm.pdf s3527 Datasheet] ja