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Wikipedia / 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 most later versions of the engine also included the Z80 (clone) CPU in a same single chip package. The S-1990, is a special case, as it's not really an MSX-Engine, but a chip that was used as "glue logic" between the MSX-engine and an external R800 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

  1. Yamaha S3527

  2. a Yamaha YM2149 PSG-sound chip, compatible with a General Instrument AY-3-8910

  3. parallel I/O chip: backward compatible with the Intel i8255

  4. standard MSX1 functions: DRAM control, slot selection, joystick ports, cassette/printer interface etc.

  5. 100 pins

Note 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

  1. Sony MB64H131

  2. Intel i8255

  3. printer port

  4. Toshiba T7775

  5. CMOS-chip with all MSX 1 functions.

  6. Toshiba T7937(A)

  7. main CPU, a Zilog Z80 (clone) with a clock speed of 3,58MHz.

  8. PSG-sound chip, compatible with a AY-3-8910

  9. Video Display Controller: T6950 rev. B (TMS9918 compatible)

  10. parallel I/O chip: backward compatible with the Intel i8255

  11. MSX 1-functions

  12. dimensions: 10,5 × 8,60mm

  13. Hitachi HD62003

  14. AY-3-8910 compatible PSG

  15. DRAM controller

  16. PPI i8255 functions

MSX 2/MSX 2+

  1. Yamaha S1985

  2. a Yamaha YM2149 a Programmable Sound Generator - sound chip, compatible with a General Instrument AY-3-8910

  3. parallel I/O chip: backward compatible with the Intel i8255

  4. MSX1- and MSX2-functions (up to 512 KB memory mapper)

  5. Real Time Clock (Ricoh RP5C01A compatible) including 26 x 4 bits RAM, backed up by (separate) battery

  6. 100 pin flat plastic package

  7. Toshiba T9769

  8. main CPU, a Zilog Z80 clone with a clock speed of 3,58MHz (MSX2; switchable to 5,36MHz on some MSX2+ machines)

  9. a Programmable Sound Generator - sound chip, compatible with a General Instrument AY-3-8910

  10. parallel I/O chip: backward compatible with the Intel i8255

  11. MSX1 and MSX2-functions (MSX2-computers)

  12. MSX2+-functions (MSX2+-computers)

  13. dimensions: 10,5 × 8,60mm

MSX turbo R

  1. NEC S1990, combined with a Toshiba T9769C

The S1990 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.

References