Mattel Aquarius

Looking to compete in the home computer market, Mattel Electronics turned to Radofin, the Hong Kong based manufacturer of their Intellivision consoles. Radofin had designed two computer systems. Internally they were known as "Checkers" and the more sophisticated "Chess". Mattel contracted for these to become the Aquarius and Aquarius II, respectively. Aquarius was announced in 1982 and finally released in June 1983, at a price of $160. Production ceased four months later because of poor sales. Mattel paid Radofin to take back the marketing rights. Four other companies: CEZAR Industries, CRIMAC, New Era Incentives, and Bentley Industries also marketed the unit and accessories. The Aquarius was often bundled with the Mini-Expander peripheral, which added game pads, an additional cartridge port for memory expansion, and the General Instrument AY-3-8910 sound chip. Other peripherals were the data recorder, 40 column thermal printer, 4 and 16 kB RAM cartridges. Less common first party peripherals include a 300 baud cartridge modem, 32 kB RAM cart, four color plotter, and Quick Disk drive. ==Reception==

Although less expensive than the TI-99/4A and VIC-20 home computers it competed against, the Aquarius was made a less attractive purchase by its comparatively weak graphics and limited memory as well as the hidden cost of add-ons required to overcome the limitations of the base unit. which was a slight because the Aquarius was developed and released in the eighties. Of the 32 software titles Mattel announced for the unit, only 21 were actually released, and most of those were ports of Intellivision games, often inferior ports. Because of the hardware limitations of the Aquarius, the quality of many games suffered. The absence of any all-points-addressable graphics mode was so glaring that Radofin crafted the character set for the Aquarius with many tiles and sub-tiles, as well as block graphics characters, so games could at least feign sprites and use semigraphics. It proved to be not enough. Decades after the spectacular market failure and exceptionally short original product life of the Aquarius, retrocomputing enthusiasts returned to this platform with renewed interest and intrigue, partly due to rarity and hacker interest in working within—and pushing—tight system constraints. Multiple homebrew games were thus published scores of years after-the-fact, and development and niche user interest in Aquarius software continues, using surviving original hardware, FPGA implementations, and emulators. ==Technical specifications==

• CPU: Zilog Z80 @ 3.5 MHz • Memory: 4 kB RAM, expandable to 36 kB; 8 kB ROM • Keyboard: 48-key rubber chiclet keyboard • Display: semigraphics ( text characters - with a 25th "zero" row at top - with a size of pixels, equivalent to pixels) in 16 colors (TEA1002 colour encoder) • Sound: one voice, expandable to four voices • Ports: television, cartridge/expansion, tape recorder, printer • PSU: non-removable external power supply hard-wired into case providing 8.8 / 16 / -19 VDC ==Peripherals==

Despite its relatively short time on the market, Mattel Electronics and Radofin managed to have most of the announced peripherals available within a month or so of the release of the system. Some products never materialized beyond prototype phase, and some were available only in specific markets. Beginning in 2016, new user-designed peripherals began to show up, mostly on eBay or on vintage computer forums such as AtariAge. ==Interfacing==

, the DIN-type external cassette drive connector, the TV channel 3/4 selector switch, the TV output connector, and the hardwired power lead The Aquarius manual did not contain detailed documentation on any of the ports available, but Aquarius FAQ files and later retrocomputing websites shared the ascertained information. Cassette port The cassette port, although using the same 5-pin DIN 41524 connector as the TRS-80, did not have the same pinout and thus was incompatible with readily available cables for the TRS-80, even though they physically fit the sockets on both the computer and cassette player. The Aquarius-branded cassette deck came with the appropriate cable. The cassette port is a 5-pin female DIN 41524 connector The MIC and EAR connections from the Aquarius each go to the tip/center of one of the two mini-plugs being attached to the recorder; Ground goes to the base/outside of both mini-plugs. Printer port The printer interface is a 3.5 mm mini-stereo socket with 3 lines (tip, ring, sleeve), the same as on the Mattel Entertainment Computer System. The Aquarius printers came with their own cables. The interface conforms to RS-232 serial signal standards (+12VDC/-12VDC), and with knowledge of its pinout it is possible to interface with RS232-compatible serial printers. Typical serial printers had DB-25 interfaces; some had DE-9 interfaces; and some Radio Shack (RS) printers had round 4-pin female DIN serial interfaces (with the pin sockets numbered left-to-right: 4, 3, 2, 1). The following shows the pinout for the printer connector on the Aquarius, as well as for connection with the aforementioned serial printers: The serial transfer protocol is fixed to 1200 baud 8N2, and provided both carriage return and line feed commands to the printer; thus the printer needed to be set to not also execute a line feed on carriage return. Because the Aquarius printer port used only a minimum number of pins (TxD/DSR/GND), the use of this port was unidirectional, from the computer to the printer (or other attached serial device). == Character set ==

In September 2024, all remaining—hitherto missing—Aquarius characters were added to Unicode 16.0, in the Symbols for Legacy Computing Supplement Unicode block. The following table shows the Mattel Aquarius character set. Each character is shown with its Unicode equivalent. ==Software==

Software published for the Aquarius during its commercial life (1983–84): :† ROM cartridge Homebrew software developed for the Aquarius: == Aquarius II ==

Just after the release of the Aquarius, Mattel had announced plans for the Aquarius II. However, before this could happen, Mattel had returned the rights to Radofin and left the market. In April 1984, a sample of the Aquarius II- now marketed by Radofin themselves- was reviewed by UK magazine Your Computer, who quoted a price of £80 and considered it "a vast improvement over the Aquarius 1". and that it was actively promoted in France, with press advertisements from its official distributor appearing there towards the end of 1984. In spite of this, it was also not a commercial success. Technically otherwise identical to the previous version, the Aquarius II came with a 16 kB RAM extension, mechanical keyboard and Extended BASIC. ==References==