Memotech Limited MTX 500, Service Manual

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1
INTRODUCTION
Overall Description
The MTX Series personal computer systems are high
performance 8-bit computers uniquely designed to
operate in memory intensive ROM-based or DISC-
based environments. The choice of the Z80 A
Microprocessor and the TMS 9929A series video
processor as the key components of the hardware
architecture is consistent with a low cost ROM-
based system with colour TV output plus the
capability to expand to accommodate a fully RAM-
based Disc operating system such as CP/M,
utilising a high quality 80 column colour monitor
output.
The memory size can be either 32K or 64K Bytes as
standard, expandable to 512K Bytes. There is a
separate 16K Byte dedicated video memory. A 24K
Byte ROM contains MTX - BASIC, the systems
monitor, supplementary languages and utilities.
The standard interfaces included are tape cassette
(Read/Write to 2400 baud), Keyboard, Cartridge
Port, Twin Joysticks, Parallel Centronics type
printer port, uncommitted Parallel Input/Output
port, colour TV output with sound, composite video
output - monochrome or colour, and audio output.
Optional interfaces include a completely
independent twin RS232C with buffered bus
extension, Colour 80 Column Board, Floppy Disc
System, Silicon disc fast access RAM boards, and a
Winchester Disc System.
The Keyboard consists of 79 full travel typewriter
style keys mounted on a steel base plate which is
fitted to the Aluminium enclosure. Aluminium was
chosen for good heat dissipation, durability and
RFI shielding.
MTX Service Manual