Mattel Aquarius

In early 1980s computers became popular not only as work tools or scientific machines, but as toys to play games. Consoles with built-in or cartridge games were around since late 70s. The idea of "home computer" - computer with keyboard and programming language, but also capable of displaying graphics and animation needed for games, started to be implemented in many computers.
Mattel Electronics, a video game division of Mattel toy company, got its most success from video consoles like Intellivision. It was designed by British company Radofin and manufactured in Hong Kong. When Mattel decided to step into home computers business, a simple way of getting a computer was getting it from Radofin.
In early 1980s, Radofin already had 2 designs of microcomputers. Simple one, internally codenamed "Checkers" and advanced model (codename "Chess"). The first has been released in 1983 as Aquarius and the plan was to release the second as Aquarius II.
The first Aquarius machines were sold below manufacturing price. The gain was in its peripherals and cartridges, which had games, memory expansions, ports, joypads or 300-baud modem. Even a CP/M emulator cartridge has been announced. Unfortunately, 4kB of RAM was too small for any serious work except learning BASIC, which occupied most of RAM already. The BASIC was also limited (however only very first units have BASIC without FOR instruction) and peripherals releases became more and more delayed. Maybe because they ordered porting CP/M to the company which designed power supply units? Graphics was not programmable easily. Finally Mattel passed all computer busines to Radofin 4 months after releasing Aquarius. Radofin made it for few years trying to sell it here and there under different brands, but never made a big success.
Right before ending microcomputer business, a small number of Aquarius II computers have been released (by Radofin), but it was not machine previously known as "Chess". It was an extended Aquarius I. The only differences were casing, full-stroke keyboard and extended BASIC in ROM... still using 4kB of on-board RAM made a 20kB RAM cartridge a must-have. The "Aquarius III", real "Chess" machine has never been released.
This is the first Aquarius model released shortly after Mattel passed it to Radofin, probably for German market. It has a Z80 running at 3.5MHz, 4kB of RAM and built-in TV modulator. Its small keyboard is not very comfortable but usable, and graphics capabilities are, for that time, below average (80x72 in 16 colors). Although most games were released on cartridges, it has tape recorder connector.

Manufacturer Radofin / Mattel

Origin UK
Year of unit 1983
Year of introduction 1983
End of production 1987?
Speed 3.5MHz
(cartridge expansion possible)
Colors: 16
Sound: 1-voice
machine-code games on cartridges
Display modes: 80x72 16colors graphics
320x192 graphics
24x40 Text mode
Media: Cartridges, tape

Power supply:

External on permanently fixed cable.

 +5V, 1,2A
+12V 150mA
-12V 10mA.

Small warning: Original power supply's transformer is quite "soft" and has even +/- 24V when not loaded.

I/O: System bus / Cartridge connector
RF output
Tape I/O
Serial printer
Possible upgrades: Possible by cartridge expanders

Accessories in collection:
  - Original box and German manuals

Software accessibility: Fair (TOSEC)

My unit is in a good condition, it was sold for German market as it has German manuals, yet in its box there are markings in French and English too. Probably it's Mattel unit re-branded back to Radofin, as most components are from 1983 and there is still "MATTEL ELECTRONICS" visible in plastic on the bottom and under the cartridge connector cover.

Important notes about hardware:
 - Most I/O ports are connected right to chips pins WITHOUT ANY PROTECTION. Pay attention to peripherals.
 - Power supply unit is only a transformer, rectifier and set of capacitors. Output voltage without any load is usually +/-24V on 12V lines and +12V on 5V line. This voltage is regulated inside computer.
 - Power pinout on mainboard:
____               _______
   | /\ /      \
RF | \/ \______/
   |     ____
   | O   1234
 __|_______________ <-mainboard edge

1 - +12V 150mA (unregulated)
2 - GND
3 - +5V 1,2A (unregulated)
4 - -12V 10mA (unregulated)

Contents: Starting Recording media Pinouts Links


The machine starts and offers option to boot to BASIC by displaying "BASIC Press RETURN key to start" on slowly blinking screen. If you press Return then, it'll start MS BASIC from 1982.

To save your current program on tape, use CSAVE (CTRL-A) and program name in quotes:


Program names can be 6 characters max. Then you press Record on tape deck and Return on Aquarius.
Verifying saved program is with CLOAD? command.

To load program, use CLOAD (CTRL-Z) followed by program name in quotes:


or just empty CLOAD to load first program it encounters. It should respond like "FOUND "MYPROG"" and load. If you type the program name and other program will be encountered on tape, its name will be shown and loading it will be skipped.

Recording media

Generally there are two formats: BIN, which are direct binary dumps of ROMs used in cartridges and CAQ, cassette dump format. CAQ can be used in emulator like Virtual Aquarius or converted to WAV by CAQ2WAV tool available in Virtual Aquarius package.
Another emulator is AqEmu, also made in early 2000s.






1 - Output (to recorder)
2 - GND
3 - Input (from recorder)



Serial printer:

1 - GND
2 - DSR?
3 - TxD

1200baud, 8-bit, no parity, 1 stop bit, hardware handshaking (DTR/DSR).
RS232-levels compatible, not TTL. Yes, you can LPRINT to a PC terminal.


Here is a good pinout of cartridge slot.




Links: - Virtual Aquarius emulator, along with CAQ games and tool (CAQ2WAV) to play them back. - Mattel Aquarius TOSEC software supplied by Mostly binary cartridge dumps, some CAQs. - Mattel Aquarius FAQ. - In collection. - Very good technical page. - Another collector's description. - Nice history description - Composite video output by use of MAX4090 chip - Aquarius modern expander.