On Tue, Apr 24, 2018 at 6:24 PM Mike Loewen via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
I have what appears to be the CPU board for a Byte Shop BYT-8:
http://q7.neurotica.com/Oldtech/S100/ByteMPU-2.jpg
BYTE 4-76 MPU C1000-1001 ASSY REV A
It appears to be missing a ROM chip, and has definitely been hacked on (weird voltage regulator or transistor in lower left).
Is it worth putting this up for auction on the site-whose-name-shall-not-be-mentioned? I also have an unbuilt PCB.
Mike Loewen mloewen@cpumagic.scol.pa.us Old Technology http://q7.neurotica.com/Oldtech/
Hi Mike, I have 2 of those boards, both built from blank boards. One was obtained from Jonathan and one was bought from the "un-named auction site". I feel they are nice boards and are usually my go-to CPU board for testing other things out. You are not missing any ROMs, the leftmost 24 pin socket is for a 8214 priority interrupt controller and the one just to the right of that is for a 8212 I/O port/latch. The proper regulator in the lower left corner should be a 79L05 (-5v in a TO-92 pkg) but my guess is who ever built or repaired the board decided to use a 7905 in a TO-220 in it's place and couldn't fit it neatly since it is much larger. Jonathan has shared links to his docs for the board in the past including a manual & hi-res schematic scan here => <http://filedump.glitchwrks.com/manuals/s100/byt_8/>. If you are going to sell it, I would probably refit the proper regulator to make it more attractive for a buyer. I don't have a good idea on price on a populated board, but the blanks boards I bought were in the $35 to $50 range. I hope this helps a little. Regards, Jeff Galinat