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The Memotech MTX Series

Memotech MTX Hardware Options


A larger selection of more detailed photos is available on the Photos page.

I have tried to include as many of the different Memotech options that I have come across but I will not have covered every possible configuration, either on this page, or the Photos page. As I have been researching Memotech's products, it has become obvious that there was a lot of "custom" configurations shipped. I suspect that this may  have been almost a "make do and mend" approach by Memotech, that probably became necessary as the business started to fail and cost cutting was a major focus of the company.

Original Memotech Hardware & Options

MTX500 32kB RAM (other specs here)

MTX512 64kB RAM (other specs here)
RS128 128kB RAM (other specs here)

I have not been able to find a good photo of the RS128, the best I have found is the one, cropped from an article on Bilgisayar Müzesi's blog. (I think that the site is in Turkish.)

RS128 - This one was advertised on ebay UK in 2013 (from Finland)

Photo courtesy of Aki Sivula

There are some additional pictures on the Photos page.

MTX512S2 256kB RAM, although 256k was installed, due to the way the machine was configured, something less than that was useable (other specs here)

There were additional options for the Series 2 which included a version of the 80 column board which fitted inside the MTX case, a 3.5" disc drive add-on similar to the SDX version.

MTX512 Undeveloped Prototype

This is an extended length MTX, some 3 1/2" longer than the standard MTX. Geoff Boyd commented "I believe this was a (very) limited run of MTX 512s with single drive Floppy disk Controller card and 80 Column card in the extended enclosure."  Other than the standard MTX computer board, the machine shown has no additional internals fitted and the rear panel identification labels are missing.

I don't think that the prototype ever made it into production.

There are some additional pictures on the Photos page.

Information & photos from Binary Dinosaurs / Geoff Boyd.


There are a few references on the internet to Memotech MTX2000 systems, but these were not a product marketed in the UK. The 3.5in disk CP/M MTX2000 series were originally made in small quantities at the behest of the Italian distributor who invested in Memotech Computers Ltd and then later used as computer for the Videowall control systems. Many of these systems had silicon disk/ram disk + ROM CP/M systems. There was never an attempt by Memotech Computers Ltd to sell these as computer systems.

(Information comes courtesy of Geoff Boyd, 09/11/2012, from his recollection of the Videowall business)

Photo coming soon

Marco Virginio in Italy has Memotech Business/2 system. Perhaps this is another model manufactured for the Italian market? Marco's system has very similar hardware to the MTX2000 described above, but the MTX logo on the keyboard has been replaced by the "Business/2" logo.

I have been unable to contact Marco, so this photo is the one from Andy's site.

Another Business/2 ?

In December 2012,  Peter Kretzschmar) picked up this interesting item, although the keyboard has an "MTX512" label fitted, the case for the main unit looks identical to Marco's "Business/2".
MTX512 in red - the Holy Grail of Memotechs?

When Memotech were bidding for the Russian contract, a couple of demonstration machines were produced in red cases. I think there may only have been two of these demo models in existence, although there are a couple more standard MTXs which have had red covers fitted using extras from the demo run (like this one), I know where one such machine is. The chances of finding a genuine red demo MTX is probably somewhat less than winning the lottery!

MTX512 in red - the show model may have actually looked like this

Geoff Boyd has advised me that the prototypes produced for the Russian contract negotiations were slightly cut-down versions of the MTX512, the numeric keypad was removed to reduce cost. Most of the prototypes were the standard black colour and only a couple of red ones were produced for "show".

MTX512 in red - the only other example that I know of.

This one owned by Noel Long, like Jim's, this is a standard MTX with a red keyboard cover fitted, rather than one of the actual demo models.

Photo courtesy of Noel Long
ROMPAK Cartridge

The edge connector at the left hand side of the MTX, normally hidden under a plastic cover, was a ROM cartridge port. A limited number of games were available on cartridge, as well as the Node ROM for the Memotech Token Ring Network called the Oxford Ring.

Only requiring a subset of the expansion bus signals, the ROMPAK had a half-length, 30-way, edge connector.

The ROMPAK is a very simple device, consisting of an EPROM, a 47 nF decoupling capacitor and the half length edge connector.

GROM from the bus is connected to CE and OE of the EPROM, with A0-A12 and D0-D7 connected as one would expect. 

The EPROM in the ROMPAK shown contains the Node Ring software, which [Tony] spent a lot of time on at Witney.

The masking tape is not for insulation, but to wedge the PCB in one slot inside the plastic case as it is too short to reach the other slot. [Tony's] Speculator fitted inside the same ROMPAK case - just!

ROMPAK photos and technical details courtesy of Tony Brewer

Memotech Speculator

Created by Tony Brewer, the Speculator was built into a ROM cartridge case that plugged into the MTX edge connector. Used in conjunction with a supporting tape, it allowed the MTX to run a number of ZX Spectrum games. Technical details of the Speculator design can be found on this page.

There are a couple of reviews of the Speculator on the Articles page.

Photo courtesy of Tony Brewer himself!

Thanks to Martin Allcorn, I now have my own Memotech Speculator

- complete with "production" version of the Speculator case

Reverse side of the Speculator ROMPAK

Another, slightly different version of the Games ROM board
Another, slightly different version of the Games ROM board - solder side
Option ROM Board

- this is my ROM board with Pascal ROMs fitted

Option ROM Board - this one has NewWord and Pascal ROMs fitted

Option ROM Board - this is an unusual example, it is mounted in an SDX disk controller type enclosure, allowing the ROM board to be plugged in externally.


All of the other ROM card examples that I have seen have an edge connector plug on the left hand side and a bare board edge connector on the right, allowing other expansion cards to be installed internally alongside the ROM board.


Photo courtesy of Adrian Graham of binary dinosaurs

RAM Expansion board

The most common expansion board seen in MTX computers, many "MTX512"s were made up of a 32k (MTX500) system board with an expansion memory board populated with the additional 32k.

The board could hold 16 RAM chips, this one (courtesy of Manfred Flume) has two additional banks of 64k RAM fitted with a custom PAL created by Manfred.
RS232 Communications and FDX System Interface Card

The header plug to the left of the DART is the connector for the 2x25 way "D" type sockets on the rear of the case - RS232-0 and RS232-1

The header plug at the top of the board is the connector for the FDX disk system.

I know of a limited number of boards that did not have the DART or other RS232 chips fitted and only supported the FDX interface.

FDX System Interface Card

An example of the FDX Interface board without the RS232 components fitted.
Courtesy of Manfred Flume
This is the combined 80 Column and RS232 card designed to mount inside the MTX and allow SDX disk systems to run CP/M. The 80 column functionality is the same as the FDX board and it has the same RGB and composite outputs.

This one is fully populated, but some boards only had the 80 Column functionality and were missing the Z80 DART and support chips.

This example is soldered to the MTX internal edge connector, making its removal somewhat problematic!

FDX Disc System          ( when is a disk not a disk? )

This was the first and largest add-on for the MTX, it was large black expansion unit which attached to the MTX through a short length of ribbon cable connected between the bottom of the FDX case and the interface connector on the RS232 board  inside the MTX. My FDX was fitted with 2 x 5.25" floppy disks and was priced at £870 when I bought it.

A version fitted with 1 x 5.25" floppy disk and a 256K Silicon Disk was also available at £995. Additional 256K Silicon Disks could also be added at £385 each.

The FDX unit contained a 6" card frame which held the floppy disk interface card, an 80 column video card (outputting RGB and composite video) as well as space for a number of the Silicon Disc cards (an option an £385 each). The FDX also provided power to the MTX, the original PSU was not needed, and also had cut-outs for expansion connectors for additional 5.25" and 8" floppy disk drives.

The FDX was based on the design of the SM1 computer which was used for software development before the MTX was available. This can be seen from the FDX system schematics on the manuals page.

FDX Single Disc System

Memotech also released a budget (£399) single disk drive, non-CP/M FDX built in the same case as the twin-drive FDX. The single drive version connected to the MTX in the same way as the twin disk version, i.e., using a ribbon cable on the base of the FDX which connected to the combined RS232/Bus Interface card in the MTX. However, the single drive version did not have the 80 column video card and used the video output from the MTX VDP.

Unlike the dual drive version, this FDX did not supply power to the MTX, the stand-alone MTX PSU was still required. This FDX does not have a case fan.

The system was supplied with a 40 column version of NewWord and seven other games and utility programs. You can read a review on the single drive FDX on the Articles page.

The system could be upgraded with the 80 column card, silicon disks, CP/M and an additional floppy or hard disk.

HDX Disc System

There was also a hard disk version of the FDX available which could accommodate a small (10, 20 or 32 MB) hard disk installed in an FDX case alongside a single 1MB floppy disk. According to the Phoenix Operator's Manual, the HDX used an 8MHz Z80H processor. I have never seen one of these, and given the expected price (unknown), I would guess that very few were sold.

It might even have looked like this!

SDX Disc System - Older Version  

The SDX was available in a number of versions, the first version consisted of an SDX controller unit which attached to the edge connector on the left hand side of the MTX case and had an IDC connector at the rear to connect to the floppy disk drive(s).

This controller supported up to two disk drives, a 5.25" drive is shown, but it was also possible to connect 3.5" drives to the same controller. The mains powered floppy drive also supplied 5VDC to the SDX controller via a 3.5mm jack output.

SDX Disc System - Newer Version

An updated version had a 3.5" floppy disk drive built into the SDX controller case which again attached to the MTX edge connector. This was the option available by the time that the MTX512S2 was released. The combined disk controller / floppy disk unit required an additional MTX power supply to provide power.

The MTX2000 and Business/2 systems in their slimmed down FDX-like also had an internal disk controller and 3.5" floppy disk drive.

100K / 250K Disk Drives

Memotech also released a "low cost" disk drive, available with 100K (£199) and 250K (£249) (unformatted) capacities. From its description, it seems that this drive used the RS232/FDX Bus Interface card (£35, without RS232) and a ROM based version of BASIC. I have seen references to these drives in the various user group magazines but have never seen either the drive or controller card.

Memotech Product Announcement courtesy of Jim Wills

DMX80 Printer 

Memotech DMX80 printer - a colour coordinated, 9-pin, dot matrix printer, manufactured by Panasonic based on the Panasonic KX-P1090. Software compatible with an Epson MX80.

There are various references to a DMX100, a 100 cps version, but I think that this was "vapour-ware" and don't think any were actually shipped.

Scanned in 2 pages, 1 printer photograph, 2 technical details

Cassette Tape Recorder

I was unaware that Memotech had released a branded cassette tape recorder until one was included with a pair of MTX500s advertised on in 2013, I would guess that very few of these were sold. This poor quality photo was captured from the ebay advert - but the seller, Dave Hickman has kindly sent me better quality photos that you can see on the Photos page.

I found a review of a non-Memotech branded Morwood "Datacorder" at, from a review in ZX-computing from Aug-Sep 1984.

The MTX Computer brochure, scanned in 4 pages :-

1 keyboard close-up, 2 description, 3 expansion options, 4 technical details


International character sets and appropriate keyboard layouts were available for UK, US, Finland, France, Germany, Spain, Denmark and Sweden. This appears to have utilised an additional ROM piggy backed onto the OS ROM and some custom wiring on the motherboard like this Danish example.

Higher resolution photos are available on the Photos page

Photo courtesy of Claus Beakkel


The Memotech HRX Multimedia PC

(Open the dedicated HRX page for more details)

Memotech developed a high resolution graphics package based on the MTX and FDX, called the HRX which was developed for picture and image processing. The features of HRX are described in the MTX Series Technical Specification . . . .

"The basic monochrome system uses a single "colour" plane and gives 4 pages of 256x256x8 bit storage giving 256 levels of grey per pixel. The colour system used three colour planes (R, G and B) giving 224 or 16 million colours per pixel. This is more than that required for colour TV (250,000 colour shades) and the extra storage capacity can be used for picture processing."

These specifications are likely pre-production, the hardware schematics show that the analogue to digital convertors had 6, rather than 8, bit resolution, giving 218 or 256 thousand colours per pixel. This was likely done to reduce the cost of the A/D convertors and associated RAM costs.

The system was designed to allow direct TV or video camera input into its frame store, the HRX had a set of analogue to digital converters which worked at video speed and fast interleaved DMA storage which allowed data to be written to the system at video frame rate (88M bit/s). This allowed the system to grab video frames in real time and perform real time image enhancement and processing.

In addition to the real time processing capability, a software package running on an MTX computer could perform fast, off-line processing of pictures stored in the HRX frame memory, including, in addition to basic dot and vector line drawing capabilities, such functions as zoom, shrink, rotate, etc.

Memotech envisaged that applications for the HRX included graphics design, image enhancement, animation etc. However, whilst the system was certainly technically advanced for its time, it is unlikely that it was commercially successful.


The HRX system gets a brief mention in the The Home Computer Advanced Course article on the Memotech company :-

"Starting with an unexpanded MTX500, the user can add disk drives and the three graphics controller boards: a 96-bit processor main controller board, a 'Frame Grabber' and a three channel A/D converter. The resulting system is able to produce animations, picture composition and graphic design up to a full typesetting capacity. The system costs around £4,500."


The HRX was also reviewed by John J. Anderson, the writer for Creative Computing, who reviewed the MTX in the June 1984 issue of the magazine, complete with an HRX image capture of himself!

Despite not being able to locate this article for a long time, I have just managed to find a copy at and posted it on the Articles page.

Sandwiched between the pages of the MTX512 review, is a half page devoted to the HRX. Anderson says "There in front of me was the most incredible video frame grabber I had ever seen."......"There have been hi-res frame grabbers before, and there will be more in the future. But the Memotech hi-res image processor represents a breakthrough in performance for the price. Sure, it's pricey - about $14,000 at the current rate of exchange for the pound sterling. But capability of this quality cost three times as much before Memotech came on the scene."

Andy Key recalls that the HRX contained a high resolution graphics card (at 256x256x18bpp) and had basic image processing, such as sharpen, blur, scale, rotate, etc. and was shown at trade shows, but he is not sure any were ever sold.

Andy also has some copies of screen captures showing the three famous actresses (no Kelly though!) below, these captures were used during system demonstrations and showed off the impressive (for the time) capabilities of the HRX at 256x256 pixels.

(These images were originally TIF images, converted to JPG for this web page).

Marilyn Monroe

Ursula Andress

Brigitte Bardot


Technical Details

Almost all of the technical details of the HRX have been lost and I believed that it was highly unlikely that any detailed technical data would ever be found. However, Tony Brewer has found some design drawings amongst the paperwork that he retained from his days at Memotech and has kindly made them available. I have created a new page for the HRX which will eventually host all of this interesting data.


Memotech Multi-Effect Video Wall

When the original Memotech company folded, Geoff Boyd continued marketing and supporting the MTX computer for a while, but ultimately, repositioned the business to market the Video Wall system. The Video Wall system was a development of the Memotech HRX, a high resolution digital video frame grabber (described above).

Memotech Video Wall systems were initially made up of a Memotech computer (RS128 or MTX512S2) with a minimum of 128K RAM, attached through the printer port to a black box (what else?) packed with electronics to drive a wall of video monitors. Some later systems were equipped with the MTX 2000 computer, before the company moved onto the industry standard PC platform.

A number of advanced Video Wall options such as time code synchronisation, mouse control, operation of the "Reflex Touch Controller" etc, required the presence of an RS232 board in the MTX. The "Reflex" controller used the RS232 interface to allow the operator to quickly select any of the available pre-programmed video wall control sequences using external devices such as an attached mini-keyboard or commercial lighting systems controllers, etc.

Cameron Video Systems (CVS) (now called Cameron Communications) were Memotech's exclusive distributors for the Video Wall system, initially in the UK and Europe, and later worldwide. The User Manual for the Cameron Video Wall can be found on the Manuals page.

Latterly, Memotech decided to market the Video Walls themselves, rather than through their distributors, Cameron Video Systems.


The Memotech Video Wall was very successful and was installed in many high profile venues, including the Hammersmith Palais in 1987, with an upgrade in 1990. At that time, this was the biggest club Video Wall in the UK, consisting of 2, 5x5 matrix displays. You can read about it in Issue 52 of Lighting and Sound International in the Library pages.

There is a small "Memotech History of Multimedia" presentation by Geoff Boyd, available on his web pages here.

The presentation shows the Video Wall at the Natural History Museum which used Memotech technology, at least when it was installed. (See Slide 7). The photo in the presentation is of Nick Moore's "Kaleidosphere".

There is a small selection of Memotech Video Wall hardware pictures on the Photos page and an extensive set of photos of my Video Wall equipment on the the dedicated Video Wall Photos page.

Further technical details of Video Wall hardware can be found in the Video Wall section of the website.

(Some of the Video wall information comes courtesy of Geoff Boyd, 09/11/2012, from his recollection of the Memotech Video wall business)

(Other contributions from Alan Wilkinson,10/01/2013 and Brian Pipe 03/02/2013)



Third Party Add-ons from the 1980s

Jaro Speed Splitter - Split speed RS-232 for Viewdata services like Prestel etc.

I bought one of these which I used with my FDX and a Pace Linnet V21/V23 modem for accessing Prestel. It's still in the loft somewhere, I'll post a photo when I find it!

SpeakEasy - Genpat Speech Synthesiser (User group add-on hardware)

I've seen this advertised in Memopad, the user group Magazine, but have not come across the hardware. It plugged into the edge connector and given the name, was probably similar to the Spectrum product of the same name which had a built in speaker. Genpat price £29.95.

Advert from Sinclair Programs, March 1984, from World of Spectrum Archive

Memotalk - Another Speech Synthesizer, this one was from Denmark. It was designed and built by Lars Jĝrgensen and distributed by Tevec-Data.

Again, it plugged into the edge connector but did not have a built in speaker, it required an external amplifier or Hi-Fi. Genpat price £33.95

Photo taken at Memofest 2013, hosted by Jim Wills, photo by Andy Key
Norbit Elektronikk "ToolBox '84" hobbyist electronics hardware interface

In early 2021, Jonas O'Brien from Norway kindly sent me a Toolbox '85 along with an almost identical box with no branding on it, other than the port names. I found that there are no electronics inside - the 9 inputs are just wired directly to the joystick connector pins. The "POT" connectors were likely only of use with computers such as the Commodore 64 which had analogue input channels connected via Atari 2600 compatable joystick ports.


 Enhancements from the present day

Andy Key


In the 1980s, Andy Key worked for Memotech writing software, including many of the best games, for the Memotech MTX range. His in depth knowledge of the Memotech software is complimented by a great understanding of the hardware.

Andy has put this knowledge to good use to produce a range of enhancements for the MTX range, including a fantastic software emulation (MEMU) and a number of hardware designs, including :-



To quote from Andy's site, "REMEMOTECH is a modern-day re-implementation of a Memotech MTX/FDX/SDX compatible computer. It implements enough hardware to allow it to run MTX BASIC, various MTX games and CP/M".

I've "built" one of these and it is great! - You can see the details of mine here.

RAM Board

RAM Expansion / Replacement Board

A RAM expansion card, which can be used in various configurations to supply RAM to an MTX computer, including recovering from attempting a failed RAM upgrade.

Andy has built a RAM board for me that I hope to use to recover my failed MTX500......  The news is that it works great! I now have a fully working MTX with 0kB on the system board and a 512kB RAM card installed inside the case.



The ultimate add on for 2012 though, is REMEMOrizer !

Again, in Andy's words, "REMEMOrizer is an add-on for a real Memotech MTX500, MTX512 or MTX512 S2 computer, built using hardware and software developed for REMEMOTECH. It provides" [an 80 column card output to VGA, an SD card as an alternative to floppy disc, additional RAM and replacement, improved ROMs].

Andy perfected the REMEMOrizer design in October 2012 and my order went in on the same day - see more details on my REMEMOrizer.

As of March 2017, REMEMOrizer sales are now up to over 50!

At this rate, Andy will soon need to move into new premises, here's  a sneak preview of the "new" factory :-)

ROM Board
ROM Card

Released at Memofest 2019, the ROM card plugs into the cartridge port and has the flexibility to provide many functions, including games ROMs, a read-only CP/M system, a Video Wall controller, etc. etc. 

Use Andy's companion COMtoROM program to convert CP/M .COM files into ROM images for loading into the ROM


Martin Allcorn & Dave Stevenson


Adding to the modern day enhancements for the MTX, Martin Allcorn has developed MAGROM. This is a small board that plugs into the MTX cartridge port and provides a suite of games that can be loaded from the ROM.

This is a photo of one of the early development boards - see here for full details of MAGROM

Version 1.1 of the production version of MAGROM

I took Martin's MAGROM design and "productised" it.
CFX is a spin off of the Compact Flash storage system developed for MTXPlus+, our modern day, fully compatible, MTX "super computer".

It uses a modified Memotech SDX ROM to give an MTX computer the ability to load and save data from a CF card using MTX BASIC "USER" extensions.

Both CFX and MTXPlus+ make extensive use of the code developed by Andy Key for his MEMU, REMEMOrizer and REMEMOTECH projects described on the Memotech pages on his website
MTX PC Keyboard Interface
MTX PC Keyboard Interface

A small PCB that fits inside an MTX computer to allow a PC (PS/2 or USB) keyboard to be used with an MTX. Can either work in parallel with, or instead of, the existing matrix keyboard.

Designed by Martin Allcorn, Bill Brendling and myself.
MTX Multi-Function eXpansion Interface
The ultimate MTX expansion?

The Multi-Function eXpansion board, an internal expansion board that provides up to 512k of RAM, SD card interface and network interface modules, a full emulation of Memotech CP/M with VGA output for both the normal MTX video output and the emulated 80 column board.



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