Tomy Tutor / Tomy Pyūta (ぴゅう太)

This is a marvelously under explored system from 1982.

I have a US Tomy Tutor, modified with a pico-psu, F18A VGA replacement for the TMS9918 video chip, and a custom built cherry switch keyboard.

I also have a Tomy Pyūta mk II, but the only mods I’ve made to it, are to tap the composite video output. This mod is easily reversable.

My Projects for the Tomy Tutor

The US Tomy Tutor I purchased, mostly worked. The 1 & 2 keys did not work correctly, making it difficult to play games. I tried repairing the pathetic thing, but I just kept making it worse. So I replaced it completely:

Pico PSU

The power supply inside the US Tomy Tutor was failing, so I replaced it. I used a PICO-PSU. This uses an external AC to 12VDC adapter, borrowed from an old laptop. And then the PICO-PSU passes the 12VDC and adapts down to 5VDC regulated power. The Tomy is also designed to require -5VDC, but this is not used by the computer once the F18A vdp replacement is installed.

The -5VDC is exposed to the cartridge port, but Tomy cartridges never used it. I suspect this was wishful thinking for adopting TI-99/4A GROM cartridges.


I haven’t written any software to utilize the F18A, but it makes it convenient to hook up to my existing VGA to HDMI setup.


The Tomy Tutor is quite the marvel to me. Just a TMS9995, sound chip, TMS9918 VDP, some ram, and rom, and you have a computer… There are no complicated PPIs or General IO 9901 chips for joystick and keyboard. Just some comparators and decoders, creatively hooked up to the IO mechanism of the TMS9995.

Someday, I’d like to decode the OS ROMs for the Tutor, and understand how much of the 4A architecture they borrowed, and what it would have taken to pull off the use of a 4A’s peripheral expansion box and peripherals, as was advertised but never realized.