More VTech hacking

Posted by pulkomandy on Sun Mar 28 21:53:57 2021  •  Comments (0)  • 

Oh wow, have I not made any progress on VTech things since 2017!?

Anyway, you may have read the previous article about this. I have mentionned this to a few people and eventually one of them contacted me, informing that there was more ongoing work on the V.Smile. Having other people to discuss things with has renewed my interest in these things.

This resulted in a 3 hour bike ride to get yet another V.Smile, including a complete set of controllers (dance mat, the two different available keyboards, and a graphics tablet. The seller asked me if I needed some games and who would be using the system. Their reaction when I told them that the console was for my own use and that I would program my own games for it was well worth the long bike ride as you can imagine.

For now this results in a new Wiki for V.Smile things and some progress in documenting the hardware there. This was a work of collecing info from old datasheets recovered from, cross-checking with the existing emulators, and a bit of guessing. I also finally started using my logic analyzer, and documented the protocol for the controllers (not all of them yet, because the graphic tablet need batteries and I don't have enough).

There is also some work in progress (not only by me, it's nice to be in a team) to write an assembler targetting the V.Smile CPU, and a development Smartridge is being worked on as well. So that should finally put V.Smile development within reach of more people.

I also contacted Bobzy again and learnt that he was working on the VTech IQ unlimited laptop (also known as the Equalizer in the US, apparently). It has 2MB of RAM, and a Motorola Dragonball EZ CPU. The display is a reasonable 480x272 pixels and support grayscales. So I found one on eBay and it will soon be delivered to me. Bobzy has been working on a Linux port, but I wonder if EmuTOS would work, to provide an alternative to Atari's own Stacy and ST Book laptops (which are either bulky and heavy or rare and impossible to find). Wouldn't it make a nice lovely little machine?

I thought this was the most powerful machine in the VTech lineup (excluding the boring modern things that run Android), but it turns out I had missed the VTech Helio PDA, which is faster and has more RAM, as well as an almost opensource OS (they published the source with a rather permissive license, except you are not allowed to use them for other hardware). I may keep looking for one of these as well (if I can find one at an acceptable price or with a flashy color plastic, not boring blue).

Considering all this new hardware made me remember that I had unexplored/undumped machines at home too. So I did some research on the CQFD Scientus, which I had come accross in a garage sale a few years ago. I thought I had broken something when disassembling it but iit turns out it was just a wire desoldered from the motherboard.

I was curious about the CQFD branding. The macine design looked somewhat similar to VTech things, and Internet knew nothing about this machine. And the motherboard has VTech chips. I discovered that CQFD is a second brand created by VTech France to position their machines more as toys (as if the existing machines didn't look enough like toys already). It apparently existed between 1998 and 2001.

Other than that the Scientus is not super interesting, I suspect it will be running a Z80 based system like many other VTech machines, but the display is just too small to do anything useful with it. Not to mention there are some empty columns, in a weird mix of text mode (where you would have 8x8 cells of pixels separated from each other) and graphics (where it would be a single continuous matrix).

I should dump the ROM still, to explore what's in it. Surprisingly it's an UV erasable EPROM, which I guess indicates that this machine was not produced in huge quantities (otherwise VTech would probably have made a proper mask ROM for it?).

Also while looking at it I found out that one chip used for sound generation is in common with the IQ Unlimited laptop. I saw a TI logo on it and now I suspect that it is only a volume control chip (as they have some in a similar package for which I found datasheets).

See you soon (well... sometimes in the next 4 years?) for more news about this!

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