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I typically solder in a socket, for several reasons:
- If/when the IC fails again, it will be less stressful on the board to swap it than to solder it again. It will also save the chip if turned out...

I am yes, near Bristol.

I sent you a PM, but since you're a new user I'm not sure if you can send/receive them yet. If you got it let me know and we can discuss payment, postage, etc.

Regards,...

I'd be interested in the following Engineering Drawings/Circuit Diagrams if you still have them:

11/23 (KDF11) Print Set
11/34
DL11
RK11
RL02 AK
RL11
RX11

I've got my TD8E working again; now I just have to give the left TU56 drive some attention.

Beside that I've been digitizing some message logs from "8BBS", the one and only PDP-8 BBS as far as I'm...

I started tracing all the signals and found out it was a solder blob all along, whoops! I must've done that when swapping out that 8242...

It now seems to be roughly in the state it was in before...

I'm looking for an H960 rack.

I'd either like to buy it, or trade for a newer DEC rack that looks like a H9644 but taller. I believe the SA600 storage array used it.

I'm near Bristol, England.

That's what I'm hoping for :)

Meanwhile I've tested the flip-flop for the unit select and it appears OK. I then followed the signal to a buffer, and have found that it doesn't always propagate a...

6527265273

This probably explained the TIMING ERROR STATUS BIT NOT SET IN COMMAND REGISTER error I was getting when running the diagnostics. What's supposed to happen (if I'm interpreting it...

The game of whack-a-bug continues...

There's an 8251 BCD to Decimal decoder on the controller that interprets the instructions being sent to it by the computer. Rather than decode correctly, it...

Rod "Panelman" Smallwood over on ClassicCMP makes very accurate replicas of the panel glass for various PDP-8s, so providing the PCB and switches are good that may be an option for you.

The later...

As evidenced by my other threads I've since found one of these.
That said I wouldn't turn my nose up at another ;)

Hi All,

I have a motherboard that I believe was from a Sun-4 4/260 or4/280.

It's untested, but visually OK apart from missing ROMs and bent pins on a couple of PALs. Selling As-Is as I have no...

Hi All,

I'm looking for a PDP-8/f or m. At a minimum I'd like the chassis with PSU, front panel, and backplane as I already have enough spare OMNIBUS boards to build up a basic system, although...

Since buying the logic analyzer, most of the chips that I'd initially suspected could have issues appear to be fine.
Meanwhile I found a copy of the TDFRMT source and produced a listing from it,...

Yup, looks like there's a problem with my Major Registers board. Fortunately I have a spare that doesn't have this problem, but I might as well run all the MAINDEC's while I'm at it...
I can now at...

Hmm, somewhere along the way I think the CPU has developed a fault...

I found Mike Thompson's simple TD8-E tests in another thread and tried checking the Command and Data Registers, and found that...

These have all since been found.

Jack,

Thanks, I'll have some more updates to it soon. The past couple of nights I've been busy with the logic analyzer, but so far haven't found anything suspect.

These are the ones I bought,...

I did, it seems pretty close at 8.41μs.

In the meantime I bought a cheapo logic analyzer so I could get a better look at things than with my 2-channel scope. I'm not sure if I'm onto something or...

Hmm, it looks as if I may have found my first bad part - an SP380 at E17. The inputs on pins 11 and 12 both go low while trying to run the formatter, but the output (NORed) on pin 13 stays low.
Pin...

I tried a couple of tapes that were known to read, write, and format correctly on the 21st, but those were the tapes I stared having trouble with a few days ago.
I tried to format another tape just...

September 4th:
While troubleshooting the left motor on the left drive, I discovered that the G847 for that drive had a bad MPSA55 transistor at Q5. The base and collector showed a dead short.
63733...

"Fixed". Kludgy but it'll do for now, at least until I find some fresh wire in the right gauge and colours.
63723

More grime... The fan was a bit hairy too.
637246372563726

But no more!...

Hi All,

Recently I bought a TU56 for my PDP-8/e setup, so thought why not document my progress here?

The story so far...

July 6th: Bought Drive from Al Kossow.
August 8th: Drive safely...

Hi All,

I'm stuck in England right now so haven't been able to get any work done on my 11/35 that's in California.
I do however have a complete KD11-A board set here, and most of a spare set back...