5 May
2004
5 May
'04
6:34 p.m.
I have the thing opened up right now. There are 24 DIP switches, three
banks of eight, labeled SW1 through SW3. The settings currently are
Eeek!
thus, with bits numbered according to the markings on
the switch banks
and 1=on, 0=off:
12345678 <--bit numbers
SW1 11110110
SW2 11000010
SW3 10110110
There is a good deal of "small" logic, CMOS and TTL in the cases I've
bothered to look at the numbers on, a bunch of discrete components, and
three socketed "big chips": a 2732 UVEPROM with a sticker on which is
handwritten "1103" and "7.9"; a 74C154 (why this is socketed I have
no
idea); and something that looks like a CPU, on which is printed various
things in various ways; I think it's probably an 8031.
Possibly. The Bit Pad 1 used an 8035. And, IIRC a 2708 EPROM. It was
certainly a 3-rail thing, since one the problems with one of my BP1s was
that the PSU stopped giving the -5V output, the EPROM couldn't be read,
and the microcontroler did nothing useful...
There's also a momentary pushbutton switch of no obvious function
(inaccessible with the cover on) labeled SW4 and a six-contact
The BP1 has a reset button, but that's accessible without dismantling the
thing.
card-edge connector of equally obscure function.
No idea. PSU input?
-tony