Hiya
>Three boards which I expect are from an SwTPc. Each bears the SwTPc
>logo somewhere in the component-side etch.
Well, that's easy then :-)
>One I feel sure is a CPU board. It bears many DIPs, all socketed (and
>all sockets populated), a 7805 and four discrete transistors or similar
>devices soldered in, and miscellanous two-terminal devices (resistors,
>caps, a crystal, maybe some others I don't recognize). The "big chip"
>is an MC6800P; I also see an HM46810P, an MC14411P, and a chip labeled
>with the motorola logo and the text "SWTBUG 1.0" and a "7748" which I
>imagine is a datecode. Everything else is in the 8- to 20-pin range.
>On the card edge is a 50-pin single-row connector with slightly over
>2.5 pins to the centimetre, with one pin space filled with plastic.
Yup, it's a CPU all right. SS-50 bus.
>Next to the SwTPc logo is the text "MP-M". I suspect the 7805s are
>intended to have heatsinks which the board has been robbed of, probably
>at the same time as the socketed chips were removed. This has a
>card-edge connector apparently identical to that on the CPU board (just
>above).
Yup, memory board.
>A board which I feel sure is memory. It's marked "MP-8M2" and has a
>SPDT switch with the positions marked "WRT. PROTECT" and "NORMAL"; next
>to one row of 8 DIPs is "UPPER 4K" and next to another is "LOWER 4K".
>It also has two 7805s, each driving power to some of the chips - their
>outputs aren't wired together. There is also a DIP bank of four
>switches.
Yup, more memory.
The 30-pin card is an I/O card for the same box. The motherboard
ran the SS-50 bus, plus a decoder to eight SS-30 I/O sites, mem
mapped of course.
http://www.retro.co.za/6809/documents/ct-apr81.pdf
W
Received on Mon Dec 13 2004 - 00:20:46 GMT