It won't come as a surprise to learn that this one is a rebadge too:Typing Tutor III Letter Invaders kind of way. The class mode, however, offers multiple lessons:
Another thing you won't be surprised by: there's not much inside. It's pretty much mostly keyboard.
If we look back at the boards, we see a dotted area outline with the legend "U1" under that folded length of stiff ribbon cable. Time to pull out more screws and turn the board over.
The first clue comes from another VTech computer called the Laser 50, though not one that Dick Smith Electronics is known to have rebadged, which was sold in several countries including the United States. It resembles a Casio Pocket Computer and functions much the same way (even with the same P0 through P9 BASIC program spaces), but has a full keyboard and a carrying handle. Hmmmmm, does this form factor look familiar?
There is precedent for subsuming multiple functions into a single chip; it makes manufacture cheaper (and these things are all about cheap). Many of the small Pocket Computers used similar all-in-one chips that contained the CPU, LCD driver, I/O, mask ROM and RAM. Armed with this information, we can comfortably conjecture that there are two in the Laser 50 because it has a 16 character display, so they must each run one half, and the Type-right just has one because it only has eight characters. Likely the only difference between the T7812 and T7813 are the contents of the mask ROM.
That just leaves what the CPU is. The Laser 50 does not have any facility for directly writing machine code programs, and we can't get into its ROM/ROMs (though if I wanted to wreck my wife's precious toy and be doomed to sleep outside forever I might be able to get the ROM out of it), but there are other Toshiba T-chips serving as CPUs in other machines. The ones I could find after a few hours of Googling include:
- T7775 (MSX). This contains a Toshiba Z80 clone CPU with Intel i8255 PPI clone I/O and clock-bus-mapper-glue, with separate VDP (video), PSG (sound), ROM and RAM. It only appeared in four systems and they all dated from 1985.
- T7826. This turns up in another cheap-as VTech device, the Whiz Kid. This unit has a copyright date of 1984. It seems even more deprived than the units here, but later, related-in-name-only toys in this series were more functional and some even had speech synthesis.
- T7937 and T7937A (MSX-Engine v1). This also contains a Z80 clone CPU (the TMP84C00A), plus other notionally discrete peripheral T-chips on die, namely the Toshiba T7766A (PSG clone) and Toshiba T6950B (VDP clone). It also carries a TMP82C55A (8255 PPI clone) and clock-bus-mapper-glue, but uses separate RAM and ROM.
- T9763, T9769 and T9769A,B,C (MSX-Engine v2). These are upgraded versions of the T7937 series with MSX 2/2+ capability, but are otherwise the same, and also use separate RAM and ROM.
Last but not least, which came first, the
chicken Type-right or the Laser 50? Given the tendency of cost-reduced designs to be follow-ons, and that T-chip numbers appear to be more or less sequential, the Type-right appears to have been a cost-reduced design based on the Laser 50. And, well, probably a better design as well. After all, hers still works.