8085 IO ports

Tony Duell ard.p850ug1 at gmail.com
Thu Jan 19 09:47:04 CST 2017

On Wed, Jan 18, 2017 at 11:42 PM, Adrian Graham
<binarydinosaurs at gmail.com> wrote:
> On 18 January 2017 at 20:13, Tony Duell <ard.p850ug1 at gmail.com> wrote:
>> Just to keep you updated, I have located one of my units that contains said
>> drive. I am rather busy at the moment with more mundane things, but I will
>> try to pull it apart and identify said capacitors.
> Thanks Tony :)

I did have a little time today so I've taken it apart and taken some photos. I
will try to upload those next time I am in the library...

If the capacitors are the ones I think they are, the larger one nearer the
edge of the board is 47uF at 25V, the other is 10uF at 25V. They seem
to be power supply decoupling (the former is between the +12V rail and
ground, the latter is fed from a low value resistor from the +12V rail and
also goes to the +ve power pin of an LM324 op-amp). That means they
are not critical. But if they have been electrically damaged, it suggest
severe overvoltage on the 12V line which could have damaged other


More information about the cctalk mailing list