--- title: MEMOTECH RS 128 categories: - Computers types: - Home Computer origins: - United Kingdom years: - '1984' cpus: - Zilog Z80 A params: name: RS 128 image: /media/museum/photos/memotech_rs128_1.jpg company: /companies/memotech company_name: MEMOTECH specs: - label: NAME value: RS 128 - label: MANUFACTURER value: Memotech - label: TYPE value: Home Computer - label: ORIGIN value: United Kingdom - label: YEAR value: '1984' - label: BUILT IN LANGUAGE value: MTX Basic, Noddy, Assembler - label: KEYBOARD value: Qwerty full-stroke keyboard, 79 keys. Numeric keypad. 8 function keys. - label: CPU value: Zilog Z80 A - label: SPEED value: 4 MHz - label: CO-PROCESSOR value: TMS-9918A video chip from Texas Instruments. SN-76489A sound chip from Texas Instruments - label: RAM value: 128 KB (up to 512 KB) - label: VRAM value: 16 KB - label: ROM value: 24 KB (Basic + assembler) - label: TEXT MODES value: 40 x 25 / 32 x 24 - label: GRAPHIC MODES value: 'four modes, maximum : 256 x 192' - label: COLORS value: 16 maximum - label: SOUND value: 3 voices / 6 octaves - label: I/O PORTS value: TV output, composite video output, 2 x joystick, Cardridge, Tape, Audio, Centronics, 2 x RS232, Bus - label: POWER SUPPLY value: External power supply unit - label: PERIPHERALS value: FDX floppy disk expansion system (with CP/M) - label: PRICE value: £399 (UK, october 1984) tabs: - photos - hardware - links - docs photos: - title: INSIDE THE RS-128 subtitle: '' text: |- The RS-128 is technically identical to the <$168$>MTX 512. The only innovation is the addition of 2 cards (64 Kb RAM and serial interface) proposed as optional addons for the previous models. **(1)** 64 Kb RAM chips.\ **(2)** TV aerial signals modulator.\ **(3)** Three ROM circuits holding the Basic interpreter, Noddy and Z80 assembler languages.\ **(4)** This first expansion card adds 64 Kb RAM to the system, only usable as a virtual disk.\ **(5)** The second expansion card offers two RS-232 serial ports. One of them can be used to connect the FDX 5.25" double disk-drive unit.\ **(6)** These two expansion cards are mainly devoted to the use of the CP/M operating system.\ **(7)** RGB video output connector for color monitor.\ **(8)** Video RAM (text & graphic) which allows main memory to be fully available for user programs and data.\ **(9)** Zilog Z80 microprocesseur running at 4 Mhz.\ **(10)** Two Atari compatible joystick connectors.\ **(11)** Tape-recorder connectors (In and Out). image: /media/museum/photos/memotech_rs128_inside1.jpg hardware: - title: FDX EXPANSION UNIT subtitle: '' text: 'MTX double 5'''' diskette drive unit allows the Memotech computers to reach the significant softwares library of the CP/M operating system. Diskettes drives are double face, double density versions, with a 500 Kb. storage capacity. Data transfer uses the computer''s serial port. It''s very slow : 9600 bauds (1200 bytes/sec.). A 80 columns card is supplied inside the case to ensure compatibility with CP/M display mode. Several software are delivered with this unit, of which word processing New Word, the SuperCalc spreadsheet and several utilities.' image: /media/museum/hardware/memotech_fdx-expansion-unit_1.jpg links: - title: http://www.atarimagazines.com url: http://www.atarimagazines.com/creative/v10n6/48_Memotech_MTX512.php text: Memotech MTX-512 evaluation from Creative Computing, John J. Anderson. - title: MTX World url: http://www.mtxworld.dk/ text: Nice page with games, technical info, emulators, pictures, interviews, tips and more - title: MTXinfo.de url: http://www.mtxinfo.de/ text: some text in German, content mostly in English - title: Wikipedia dedicated page url: http://en.wikipedia.org/wiki/Memotech_MTX text: '' docs: - title: MTX TECHNICAL SPECIFICATION url: http://mtx.interactive.as/ cover: /media/museum/docs/couvs/memotech_mtx-tech-sepc.jpg text: |- **MTX TECHNICAL SPECIFICATION**\ written by Memotech  compiled/archived by El Senator\  type of document : ZIP\  source : [MTX Series - the good old times](http://mtx.interactive.as/) **... READ THE ONLINE VERSION BY CLICKING BELOW :** comments: - author: Roger Jowett (Ulster Londonderry) date: Saturday 6th April 2013 text: |- http://www.youtube.com/watch?v$zsjTpFR0oYQ please help we have zx spectrum 48k and one 128k program running at 6mhz using external ram and snapper discs from velesoft site - author: Roger Jowett (Ulster Londonderry) date: Saturday 6th April 2013 text: |- http://www.youtube.com/watch?v$zsjTpFR0oYQ please help we have zx spectrum 48k and one 128k program running at 6mhz using external ram and snapper discs from velesoft site - author: Claus (Sweden) date: Friday 13rd July 2012 text: Hmmm, is said same Sound and VDP as MSX, i dont think so. Memotech use a Texas Soundprocessor, wich is equal to Colecovision and Sega SC-1000 console. But not compatible with MSX, sound data can by the way be converted, but is not compatible. I know this since i have been converted a few MSX games to Memotech, read more at www.mtxworld.dk - author: Thomas date: Friday 24th June 2011 text: Does anyone know which CHIP was used to give the 80 column display on the RS128... ?? If so please leave a comment - author: Lez (England) date: Tuesday 21st June 2011 text: The RS128 had a second video processor giving a color 80 column display. It also had a ROM board for adding Roms and RS232 ports. But basically it was an MTX512. related: - /museum/memotech-mtx-500-512 oc_id: 202 source: url: https://web.archive.org/web/20230205013511/http://www.old-computers.com/museum/computer.asp?c=202 date: '2023-02-05' --- The Memotech RS128 is the successor of the [Memotech MTX 512](/museum/memotech-mtx-500-512/). It looks like the MTX 512 and has almost the same characteristics. Like the MTX 512, it sports an aluminum case. Contrary to the MTX, it has RS-232 built-in interfaces, primarily used to connect the FDX floppy drive (the data are sent from the disk to the RAM at a whopping 9600 baud!). The FDX unit comes with a 80 columns card and allows the RS128 to run CP/M programs.\ It was supplied with NewWord (word processor) and SuperCalc (spreadsheet).\ Only the lower 64 KB can be used, the upper 64 KB are used as a RAM disk. Similar the MTX512, the RS128 has characteristics very near of the [MSX computers](/museum/msx-1/) (same sound chip & video for example) but wasn't able to use MSX software.