16 Oct
2007
16 Oct
'07
2:05 p.m.
On 10/16/07, William Donzelli <wdonzelli at gmail.com> wrote:
Multiwire, as was pointed out elsewhere (though there's another
technology that we used for our VAXBI boards, called "Unilayer" which
is much like Multiwire, except, I think, the difference is that the
Unilayer wire nest is laid out on a bit of pressure/heat-sensitive
adhesive sheet, then bonded to the substrate as a unit, not one wire
at a time.
...The RDM
board is bad, but that's not required
to get the machine to run. It appears to be failure of
the RAM on the RDM board, actually. Which of course is
soldered to the board, and there is no diagnostic
routine to find out which chip is bad...
Most (all?) RDMs for the VAX-11/750s were made from that odd circuit
board process where wires are laminated right to the board (the name
escapes me right now, and I will remember just after sending this). Those boards could develop faults from the wires
breaking.
I suppose that's possible, but unless there has been mechanical damage
or massive cyclical temperature shifts, I think the wires are somewhat
sturdy. I certainly can believe there's a bad SRAM on that board,
especially if they are 2114s or similar.
But as the OP said, it's not an essential board.
-ethan