[abc80] Super Smartaid Cartridge

[H. Peter Anvin]

On 4/23/19 12:17 PM, Mikkel Christensen wrote:
>
> The yellow bricks ... any idea what they are? You can zoom in on them
> here:
>
> https://www.mikjaer.com/pics/IMG_3761.JPG
>
> It says 100nM63
>
> is that capacitors?
>

Yes; almost certainly used as decoupling capacitors on the power supply
(near each IC) to reduce noise.

> Finally i discovered that some of the scripts has silkscreens on the
> bottom?
>
> https://www.mikjaer.com/pics/IMG_3757.JPG
>
> Can we use that to figure out what they are?
They are probably lot numbers and are unlikely to be very meaningful.

The two large chips on the left are 8K (top) and 2K (bottom) EPROMs; I
bet reading out their contents will tell a *lot* about how the rest of
the board is set up.

Given the era, it is likely a simple 2-layer board, which would make it
possible to trace the connections; that would add even more clues.

I am willing to bet good money that the 14- and 16-pin chips on the
right are at least mostly 74LS or possibly 74S series chips; it is
*possible* some of them might be 4000 series CMOS chips used to build a
real time clock or similar; if so, those chips would be fed off the battery.

On 4/23/19 12:21 PM, Mikkel Christensen wrote:
> This one:
> 
> https://www.mikjaer.com/pics/IMG_3757.JPG
> 
> Seems to be this one:
> 
> https://www.alibaba.com/product-detail/Original-New-ic-SN74LS245N-DIP-74_60600814878.html?spm=a2700.7724857.normalList.89.361690f6MR2dEb
> 

Oh, you're right... it says LS245 and I didn't think that that was
simply a 74LS245. That is an 8-bit bus transceiver, that is a buffer
that can be turned in either direction; it would naturally be used to
connect to the data bus lines.

There is enough writing still left on the big chip in the middle that it
is clearly a 6116 series (2Kx8) CMOS RAM.

Incidentally, for details on chips still in production I usually go to
digikey.com and search, because you can get the data sheets directly
from there.

	-hpa