Interesting... PDP-8/m Mem problems

OK, granted I don't know what I'm doing, but... I don't think there is anything wrong with the G104 board. I've been examining E24 and E28. The problem with E28 is it's not getting any input, and unless I'm mistaken E24 isn't either. The board is broken into 3 sections, and I've also checked the section next to it to get a better idea of what I should be seeing. Now for some very un-technical talk. I've been trying to find the lines that bring the bits from the Core board to the G104 board. As far as I can tell the bits are brought over on the back side of connectors 'F' and 'G'. There are 12 dual pin groups. The four that correspond to E24 and E28 aren't acting right. With the logic probe, when examining locataions, I only get a beep on the 8 that are acting right when it checks Memory locations: xxx0 - xxx3 (the ones effected by the bad 8251 on the G227 board). On the other 4 I always get a beep, no matter what location. So.... My conclusion is that the section on G104 that contains E24 and E28 isn't getting any bits, and may very well be a totally functional section. Having said that, I'm more than a little stumped as to how to attack the Core Board itself seeing as how it's sandwiched between two other baords. Zane | Zane H. Healy | UNIX Systems Adminstrator | | healyzh(a)aracnet.com (primary) | Linux Enthusiast | | healyzh(a)holonet.net (alternate) | Classic Computer Collector | +----------------------------------+----------------------------+ | Empire of the Petal Throne and Traveller Role Playing, | | and Zane's Computer Museum. | | http://www.aracnet.com/~healyzh/ |