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 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 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 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.

Overview

Here is a short overview of MSX-Engine chips.

MSX 1

;Yamaha S3527
[Image:S3527 01.jpg|200px|right|thumb|Yamaha S-3527 MSX-Engine]

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 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
;Sony MB64H131

Intel i8255
printer port

;Toshiba T7775

CMOS-chip with all MSX 1 functions.

;Toshiba T7937

main CPU, a Zilog Z80 with a clock speed of 3,58 MHz.
PSG-sound chip, compatible with a AY-3-8910
Video Display Controller: T6950 rev. B
parallel I/O chip: backward compatible with the Intel i8255
MSX 1-functions
dimensions: 10,5 × 8,60 mm

; Hitachi HD62003

AY-3-8910 compatible PSG
DRAM controller
PPI i8255 functions

MSX 2/MSX 2+

;Yamaha S1985

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
Real Time Clock including 26 x 4 bits RAM, backed up by battery
100 pin flat plastic package

[Image:T9769C 01.jpg|200px|right|thumb|Toshiba T9769C MSX-ENGINE]
;Toshiba T9769

main CPU, a Zilog Z80 clone with a clock speed of 3,58 MHz
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+-functions
dimensions: 10,5 × 8,60 mm

MSX turbo R

;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 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.