19 Jul
2005
19 Jul
'05
10:44 p.m.
On Tue, 2005-07-19 at 20:28 +0100, Tony Duell wrote:
Conveniently, the heatsink fell off the PGA during cleaning (I wasn't
even poking at it, so the heatsink compound must have seen better days)
The chip's a 32332 - google suggests that's a second generation 32032
CPU, although it's not a part number I've come across before (we've got
some Natsemi databooks at BP; I'll have to see if it's listed)
Nice tip, ta :) I've nuked as much of the corrosion on the motherboard
as is possible and (as Sellam suspected) it's not too bad - I can see me
needing to redo some of the joints on the battery board, but I think the
motherboard may well be OK as-is.
Next on the list is re-fixing that heatsink and dumping the ROMs. PSU
test after that, then I need to find the battery board schematic I drew
ages ago for the MG-1 (they use the same board) and figure out how to
bypass the charging circuitry...
I've got a monitor with the machine, but not had a good look at it yet -
I'm not sure if I have a video lead so might have to break out the
'scope and work that one out.
Of course the hard disk may well be toast, in which case it's all for
nowt... getting MG-1 OS media is difficult enough, I expect it'd be
impossible for the 200 series machines!
cheers
Jules
On Mon, 2005-07-18 at 17:28 -0700, Vintage Computer Festival wrote:
> On Mon, 18 Jul 2005, Jules Richardson wrote:
Having now managed to see said pictures, I wonder if the CPU is on the
daughterboard. In particular, could the PGA package be something like a
32032? The other 2 'intersting' chips on said board might be an MMU and
FPU or something. Hmm, the
vinegar trick should probably go in the FAQ (along with the
fact that it tends to remove ink on ceramic chips - found that one out
the hard way once!)
I find citric acid more pleasant to use than vinegar, and just as effective.