68k Mentat

The I.Q. Unlimited is an 8-bit home computer released by VTech (under their Advantech imprint) in 1991.


features of the computer include:

  • a Z80 processor, rated at 6 MHz but likely clocked at a slower speed.
  • a proprietary BASIC dialect, with a “BASIC Tutor” program designed to teach users how to program.
  • 10 other programs, including productivity and games.

The following ICs are on the computer’s mainboard:

  • a Zilog Z80 CPU (Z84C0006PEC)
  • a ROM containing 12 built-in programs (VTech LH534HY9)
  • a custom A/V controller (VTech 27-5063-01 1111F0249)
  • an I/O controller (TMP 42C50N)
  • a printer buffer (PC 74HC244P)
  • 128KB SRAM (Toshiba TC518128APL-10)


The computer’s hardware is largely compatible with VTech’s 1988 game console, the Socrates. Socrates game cartridges can fit in the I.Q.’s ROM slot, and reportedly games will function properly.

Two Socrates games require the console’s voice module add-on, and so will not work fully on the I.Q. Unlimited. I don’t own a voice module, but it does use the same size edge connector as the I.Q.’s unused floppy drive connector. It may be possible that the voice module would work, but you would have to remove the computer’s case in order to fit the cartridge.

On the I.Q. Unlimited, this expansion port was never used. It was intended to connect to a disk drive for permanent data storage, but the drive was never released. Instead, owners could use a RAM cartridge which provided an additional 64kb of storage accessible as drive C:.

Laser MSX

1985: VTech planned an MSX computer called “Laser MSX”, but decided to instead release an independent line of z80 computers, the Laser 350 / 500 / 700 / 750. All but the 350 used the case mold originally intended for the Laser MSX.

The Laser 750 contained 128 kb of RAM and a

[[ this section under revision ]]