Setting up a VAXstation
ard at p850ug1.demon.co.uk
Thu Oct 4 12:53:49 CDT 2007
> > > I think we need to keep in mind
> > > Also, I do not have any of the tools or parts to crimp anything onto
> > > anything. I never have had and have never crimped a cable in 20y in
> > > the computer business, from junior workshop bod to IT manager for an
> > > international stockbroker.
> > Next you'll be telling me you've never used a soldering iron, 'scope,
> > logic analyser or machine code monitor either...
> I own a soldering iron and sometimes manage to use it without burning
I often get burns from soldering, but mainly because I am soldering quite
large bits of metal and i've not waited for them to cool down
sufficiently before handling them. 4mm plug pins are 'good' for this...
> myself too badly. I recently bought my first multimeter, as it was
> very cheap in Lidl and I thought it might come in handy some time,
There have been reports of the accuracy -- or lack of it -- of those
cheap meters, Many of them do odd things if the internal battery is flat
(and don't rely on the 'battery low' indicator for this), and there have
been problems due to the poor quality switches used.
A friend of mine was nearly killed due to this. He tested some wiring for
voltage-to-earth and the meter said it was essentially dead. SO he
started workign, alas the meter was malfuctioning, and he got the full
mains volatege across him. He imediately went and bought an expensive mad
> though I confess I don't know when, exactly. It's still in its box.
> 'Scope? Oscilloscope? No, never. Logic analyser? I only have a hazy
> idea what one is. Not sure I've ever seen one. M/C monitor? Not since
A logic analyser is a bit lile a 'scope in that it displays a grpah of
signals against time. The differnces are (a) it records the signals and
displays the recorded version (some 'scopes do that too -- storage
'scopes), (b) it only works with digital signals (it doesn't display the
voltage, only whether they are high or low), and (c) it has many more
input channels (even a good 'scope rarely has more than 4 channels, a
logic analyser will have 16 or more).
> Nope, in two decades of professional computer fettling, from minis to
> mainframes to workstations to PDAs to smartphones, and of course PC
> servers, laptops, desktops and many Macs, I've never soldered a chip
> or a PCB, never done anything more than remove & replace a socketed
I am puzzled by people who want to run old hardware, but who don't want
to learn to repair it to component level. I can understand why people
want to run the software under emulation (even if that's not what I want
to do), but I am seriously wondering what extra you get from running the
old machien _other_ than being able to fully understnad and repair the
Notice I said 'I am puzzled' not 'you are wrong'. Perhaps somebody could
> chip. I've built more machines than I can remember, fixed innumerable
> broken ones, restored old dead ones and given them away or sold them,
> but generally, to me, the smallest unit of a computer is a circuit
> board, and when one is dead, it gets thrown away and replaced.
I tend to take it to extremse the other way. I've rewonsd motors, made
mechanical bits from raw metal, kuldged in the 'wrong' chip, and so on.
How do you repair vintage machines when spare boards are not available?
And please don't throw away PCBs from vintage machines, even if they're
defective. Somevody else might be able to repair them, or use parts off
them. For example one machine I am currently working on has a RAM board
containing 16 off Intel 1103 DRAMs. These were the first 1Kbit DRAM chip
(35+ years ago...) and are very hard to find now. If one of those chips
fails and you replace the board, the old board could supply 15 very
useful chips to somebody else.
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