Mattel Aquarius Mini-Expander
| Mattel Aquarius Mini Expander | |
|---|---|
 |
|
| An Aquarius with the Mini Expander fitted behind it, holding a 4K memory cartridge and a game cartridge, and its two hand controllers (Jzh2074, CC BY-SA 4.0) | |
| Manufacturer | Radofin for Mattel Electronics[1][2] |
| Type | Expansion unit: two cartridge ports, two hand controllers, extra sound channels |
| Interface | Aquarius cartridge and expansion port |
| Compatible | Mattel Aquarius, Mattel Aquarius II[3] |
| Model | 4063[1] |
| Power | +5 V from the Aquarius[4] |
The Mattel Aquarius Mini Expander (model 4063) plugs into the cartridge port of the Mattel Aquarius. It adds a second cartridge port so that a memory cartridge and a program cartridge can be used together, two detachable hand controllers, and a sound chip that gives the Aquarius three sound channels.[1][2] Mattel also packed it with the computer, the printer and the data recorder in the Com/Pac package.[1]
Hardware
[edit | edit source]The Mini Expander has no power supply of its own and runs from the Aquarius's +5 V. Sean Harrington, who redrew and recreated it as an open-source board, describes it as a simple device of about 25 components.[4][5]
| Part | Function |
|---|---|
| AY-3-8910 | Sound generator and the two 8-bit I/O ports that read the hand controllers |
| 74LS244 (two) | Address buffers |
| 74LS04, 74LS02, 74LS30, 74LS74 | Address decoding and the sound chip's control lines |
| 2N3904 transistor | Mixes the sound chip's output into the Aquarius sound line |
| L1 (33 µH) with C8 (10 µF) and ceramic capacitors | Filter on the +5 V supply |
Harrington checked his recreation against Radofin's original schematic and corrected minor differences from the actual board.[4][5] MAME also emulates an AY-3-8910 in the Mini Expander, clocked at half the Aquarius processor clock.[6]
The sound chip is given differently elsewhere: the Aquarius FAQ calls it "the same as used on the Intellivision", and the computer historian Erik Klooster names it as the AY-3-8914.[1][7] Check the part on your own board.
Ports and controllers
[edit | edit source]The Mini Expander has two ports on top. Mattel's instructions put program and game cartridges in the front port and the 4K or 16K memory cartridge in the back port; with the 4K cartridge the Aquarius has 8K in all, with the 16K cartridge 20K.[2] Harrington's recreation adds solder jumpers so that RAM or ROM can be used in either slot, which the original does not offer.[5]
Each hand controller has a 16-position disc and six action buttons, and a detachable coiled cord about 8 feet (2.4 m) long.[2] The controllers resemble the Intellivision's but have six keys instead of twelve and no side buttons.[1] They are read through the AY-3-8910's two I/O ports.[4][8] Inside, a nine-wire cable runs to a conductive mylar pad, and the plugs are the same DE-9 type as Atari and Sega joysticks use, although those joysticks do not work in the Mini Expander.[5]
Use and care
[edit | edit source]- Turn the Aquarius off before sliding the Mini Expander into the cartridge port, and turn it on again only when the Mini Expander and cartridges are in place.[2]
- Hold the plug, not the cord, when unplugging a hand controller.[2]
- Do not lift the Aquarius by the Mini Expander or by the hand controllers.[9]
- Memory cartridges hold their contents only while the power is on; save programs to cassette.[2]
Repair notes
[edit | edit source]- The only electrolytic capacitor in the recreated circuit is C8, 10 µF, on the +5 V supply after the 33 µH choke L1. Check the value and polarity on your own board.[4]
- Harrington found the 33 µH choke hard to source for new boards and suggests bridging it with wire or a 0 Ω ferrite bead.[5]
- Each controller is a conductive mylar pad wired through a nine-wire cable. If directions or buttons are missing, check the cord, the plug and the pad. Harrington's recreation includes small boards that join the cable to the pad.[5]
Documentation
[edit | edit source]- Mattel's Mini Expander instructions (4063-0920, 1982), described on Mattel Aquarius Documentation.
- Aquarius Mini Expander v1-1-0 Rev C schematic (Harrington, 2021, GPL).
Related pages
[edit | edit source]- Mattel Aquarius
- Mattel Aquarius II
- Mattel Aquarius Documentation
- Mattel Aquarius General Maintenance
References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Fred Horvat and Gil Parrish, "Mattel Aquarius FAQ", last updated 6 May 2001 (retrieved 2026-10-19), "What Hardware was Released?": Aquarius Mini Expander, model 4063; two detachable 6-key, 16-position disc hand controllers, like the Intellivision's with 6 keys instead of 12 and no side buttons; "a decent sound chip (the same as used on the Intellivision)" giving 3 sound channels; two cartridge slots, one for memory and one for a program; Com/Pac package; model numbers ending in C were CRIMAC products and the others Radofin products.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Mattel Electronics, Aquarius Mini Expander instructions, 4063-0920 (illustrations © Mattel, Inc. 1982), hosted here as File:Aquarius Mini Expander Instructions.pdf: contents (Mini Expander, two hand controllers each with a detachable 8' coiled cord); make sure the Aquarius is off, slide the Mini Expander into the cartridge port; front program/game port and back memory port; 4K cartridge gives 8K and 16K gives 20K; memory cartridges store information only while the power is on; 16-position disc and 6 action buttons; hold the plug to remove a controller.
- ↑ Kathleen Peel, "Review: Aquarius II", Your Computer, April 1984, p. 64, Internet Archive copy (retrieved 2026-10-19): the Aquarius II uses the peripherals designed for the first Aquarius; the Mini Expander adds two joysticks, a cartridge and a memory port and costs £40.
- ↑ 4.0 4.1 4.2 4.3 4.4 Sean P. Harrington, Aquarius Mini Expander v1-1-0 Rev C schematic, 14 February 2021, hosted here as File:Aquarius Mini Expander v1-1-0 Rev C Schematic.pdf: AY-3-8910 (U1) with I/O ports A and B to the control pad connectors J3 and J4; 74LS244 address buffers U2 and U3; 74LS04, 74LS02, 74LS30 and 74LS74; 2N3904 sound mix and amplifier; L1 33 µH and C8 10 µF on VCC with ceramic C1-C7, C9, C10; front and rear card edge ports.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 Sean P. Harrington, Aquarius Mini Expander 1-1-0, README (GitHub, retrieved 2026-10-19): expands sound to three voices and adds a RAM slot, a cartridge slot and control pad ports; "only about 25 components"; an excellent Radofin document records the original schematic and was used to verify the recreation, with minor discrepancies corrected from the actual board; solder jumpers added to allow RAM or ROM in either slot; the L1 33 µH choke is difficult to source and may be bridged with wire or a 0 Ω ferrite bead; small control pad interface boards join the nine wires of the controller cable to the mylar pad; switchable use of Atari or Sega joysticks not supported "despite the same DB9 plugs".
- ↑ MAME source, src/devices/bus/aquarius/mini.cpp at commit eee415b (retrieved 2026-10-19): "Aquarius Mini Expander", AY8910 at the derived clock divided by 2; two cartridge slots; 16-direction controllers with six buttons each.
- ↑ Erik Klooster, "Mattel Aquarius - home computer with the shortest career", History of Home and Game Computers (as quoted in Wikipedia's Mattel Aquarius article, retrieved 2026-10-19): "the Mini Expander was equipped with the same sound chip (AY-3-8914) as the Intellivision".
- ↑ M. van der Steenoven, "The handcontrollers", Mattel Aquarius Homecomputer system technical information (retrieved 2026-10-19): the hand controllers are read through I/O ports A and B of the AY-3-8910.
- ↑ Radofin Electronics (Far East) Ltd, Aquarius Guide to Home Computing, 5931-0038R-1 (1983), retyped transcription hosted here as File:Aquarius Guide to Home Computing (Radofin edition, retyped).pdf, from the Internet Archive item AquariusGuideToHomeComputing (retrieved 2026-10-19), "Key points for trouble free use": never lift Aquarius by external wires, by the Mini Expander or its hand controllers.