[abc80] Super Smartaid Cartridge

Peter Bortas zino at lysator.liu.se
Tors Apr 4 18:13:13 PDT 2019

Hi Mikkel,

On Wed, Apr 3, 2019 at 2:46 PM Mikkel Christensen <mikkel at mikjaer.com> wrote:
> My name is Mike, i run this small YouTube channel where i restore old
> computers, and currently im workin on an ABC 80!

Nice videos. As an aside, that keyboard might very well have been
working when the seller sent it. 100% of the Keytronics keyboards of
that generation is deteriorated to the point where they might work
when you take them down from the attic, but the foam doesn't really
stand up to transport. And since it was some discussion of if the
contacts where of the inductive or shorting type: They are inductive.
It might look like they conduct, but unless they have been damaged the
little foil bit that touches the keyboard has a see through isolating
layer at the bottom.

> Mine has this "Super Smartaid" catridge which is giving some problem,
> se the next 10 seconds of this video for the symptoms:
> https://youtu.be/H6KNZi3cBZ8?t=94
> I have taken it apart and discovered a leaked battery, which i plan to
> replace and to clean the board this next weekend.

For a leaking battery damage that looks pretty good. Here's hoping
there's no hidden damage!

> But i also tried to look around for schematics, rom images or
> information about the circuit in case my beforementioned attempt does
> not work. But it looks like the silkscreen has been sanded of the
> integrated circuits, and i have had no luck whatsoever finding anything
> about this cartdrige.
> Can any of you lend me a hand?

Let's see what we can do. You probably know step 0: Put some black
electricians tape over those EPROM windows before they die from
exposure. No Super Smartaid ROMs are listed in Mame, so it would be
great if you could dump them so we can get them emulated and saved for
the future.

That cartridge seems to be a a number of pretty neat convenience
extensions to Basic, you can find the manual here:
Let me know if you need help with any of the Swedish.

Those ICs with sanded text is very likely to be dead simple LS74
address decoding stuff. Why anyone would sand them while keeping the
text on the RAM is beyond me. The battery seems to be a backup of
settings, and the manual describes situations where the settings RAM
can get corrupted and make the machine unusable. It has the reset
procedure to fix that described under "RESERVUTGÅNG".

The manual also says that version 2 (which you have according to the
startup screen) will abort all programs after 8 * Ctrl-C. So that
might also be something to try when you get that strange startup

Best of luck, and keep us updated!

Peter Bortas

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