5 Feb
2009
5 Feb
'09
12:38 a.m.
Hi all
I had a super Xmas break and as a result The following have been
restored to factory spec and are running.
On TCP/IP network
VAX 4000 M500
VAX 4000 M200
MicroVAX 3100
VAX Station 3100
Alpha 3000
Alpha Station 200
Stand alone
Rainbow 100+ Needs a DECnet adapter
11C23 Running Micro RSX needs the DECNet board (which I do have) and
the Cable which I don't.
Decmate III
Working Periperals
VT200's
VT320's
VT240
Awaiting Parts/Attention
PDP 8e - Has a difficult to trace hardware problem
It was running but now I can't toggle in a test proigram.
Set address -> DEP -> Set Data - > DEP (Increments the
address ok)
Go back and examine memory = nothing.
System has four x 4K core memory.
Removing any one or three out of four makes no difference.
I'm rusty on PDP8's ( I last worked on one in 1972)
Help!!!!!!!!!!!!!
VAX 4000 M300
(Needs the upper outer door and the door for the front of
the CPU compartment
PRO 350 Needs a RD-5X MF ST506 Drive
PRO 380 Needs a RD-5X MF ST506 Drive
VT 103 (Needs a monitor board)
PDP-11/94 (Needs KDJ11-EB = M8981-BA)
Wish List
DEC logo colour monitors of any type.
VAX VLC's
11/05
11/10
11/34
11/70
RL01's
VT100's
VT102
VT4XX
LA36
LA180
BA123 (Enclosure)
BA23 (Enclosure)
11X94-E (Enclosure)
Rod Smallwood
6 Feb
6 Feb
10:54 a.m.
PDP 8e - Has a difficult to trace hardware problem=20
It was running but now I can't toggle in a test proigram.
Set address -> DEP -> Set Data - > DEP (Increments the
address ok)
Go back and examine memory =3D nothing.
System has four x 4K core memory.=20
Removing any one or three out of four makes no difference.
I'm rusty on PDP8's ( I last worked on one in 1972)
Help!!!!!!!!!!!!!
Why do you say this fault is hard to trace? Have you tried to track it
down (and if so, what did you find)?
In general, faults that 'stay put' are a lot easier to find that
intermittants, which have the 'interesting' habit of vinishign as soon as
the 'scope or logic analyser is next ot the machine :-)
Anyway, it's been some time since I've worked on the 8/e, althogh I know
whre the maintenance manuals are if you want me to figure things out. But
with a fualt like this, I think I'd start by looking at the Omnibus lines
-- is the CPU outputinng an address, data, and the appropriate control
lines? If not (and the fact that none of your memory works would seem to
indicate a CPU fault), then work backewards from the incorrect/missing
bus signal.
-tony
5798
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ard＠p850ug1.demon.co.uk -
RodSmallwood＠mail.ediconsulting.co.uk