On Sat, 25 Aug 2012 19:30:12 +0100 "Gareth Magennis"
wrote in Message id:
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"Gareth Magennis" wrote in message
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"JW" wrote in message
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On Wed, 22 Aug 2012 09:57:52 +0100 "Gareth Magennis"
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Hi,
can't seem to even find a printable datasheet for this well obsolete
device.
Its an 8080A controller/bus driver, just wondering if anyone knows where
I
might find a replacement - perhaps someone knows of a common old piece of
equipment that might have one I can salvage.
This is in an AMS DMX 1580, a digital delay from the last century.
Ebay?
http://www.ebay.com/sch/i.html?_from...&_nkw=uPB8228C
Datasheet:
http://www.datasheetarchive.com/UPB8228C-datasheet.html
Intel also made the 8228. Very likely that Intel designed it, and NEC
copied.
Oops, must have made a typo when I searched Ebay yesterday.
There's one on Ebay UK too which I've just bought.
Cheers,
Gareth.
Damn, replacement didn't work.
Reason for suspecting this device was that the systems _WR line was held at
around 1 volt, other Address/Data lines look normal.
Isolating this device from that line produced a solid zero, so worth a punt,
I thought.
On boot up there doesn't appear to be any activity on the _WR line at all.
Sigh. Could be anything.
Do you have a schematic? The _WR line comes from the CPU, but perhaps it
goes somewhere else. Could the CPU itself be bad?