http://www.stardot.org.uk/forums/viewto ... f=8&t=4281
The old black box electronics, its a small plastic tray into which someone has put some electroncs, dangled a cord out one edge, then filled the whole thing with black epoxy.

Ok so what's inside ?
Best guess its a 146818 RTC chip, a battery and other bits and pieces.
Reasoning is it would:
a) Fit inside the casing (just).
b) Interface easily with the userport, its 8 bits plus some read/write signals which could be multiplexed.
c) Its common as mud, hence the need to hide it in epoxy.
d) Its included in the later Master 128, and strangely if you use a Master with certain versions of Level3 you don't need the external RTC.
Anyway, all I can get out of it at the moment is the number 223. Which does mean I am reading something at least.