User`s guide

7
1. INTRODUCTION
REMEMOrizer is an add-on for the Memotech MTX series of home computers which were produced
in the UK between 1983 and 1985. The range included the MTX500, MTX512, RS128 and MTX512
Series 2, these were all Z80 based machines, the major difference between them being the amount
of installed Random Access Memory (RAM).
As was typical of similar home computers of the time, the base models were limited to a display
resolution of 40x24 characters or 256x192 pixels and relied on the use of Compact Cassette tapes as
their storage medium.
A number of expansion options were available at the time, including disk based storage systems
(FDX and SDX) which allowed the user to run the industry standard CP/M operating system with an
80 Column card installed.
Although some cheaper disk options were introduced late in the machine’s life, these were not
common and most users had to make do with video output to TV or low resolution monitor and tape
based storage.
REMEMOrizer is a 21
st
Century enhancement for the MTX that provides random access storage
capabilities, using Secure Digital (SD) cards emulating floppy disks, and 80 Column mode output to
Video Graphics Array (VGA) compatible monitors. In short, it’s an SDX, only smaller, faster, cheaper
and better. This is the upgrade you wished you'd had in 1984.
REMEMOrizer provides the following enhancements :-
 80 column card, with 80x24 and 80x48 modes, outputting to 640x480 @ 60Hz VGA
 SD Card as a large and fast alternative to floppy disk
 512KB of extra memory
o 320KB is directly usable, and is typically used as a RAM Disc
o 128KB is hidden, and is used as virtual cassette
o 32KB can be used to upgrade MTX500s to 64KB, with a PAL replacement
o 32KB can be used if your MTX has no memory at all (ie: a failed upgrade)
 CP/M boot ROM and SDX BASIC ROM providing access to SD Card and RAM Disc
 Replacements for the fixed OS and BASIC ROMs, providing Virtual cassette support
REMEMOrizer was designed by Andrew Key (email: [e-mail])
The latest copy of the REMEMOrizer documentation and technical data can be found on-line at
http://www.nyangau.org/REMEMOrizer/REMEMOrizer.htm.