8085 IO ports

Adrian Graham witchy at binarydinosaurs.co.uk
Sat Jan 21 10:06:10 CST 2017

On 19/01/2017 15:47, "Tony Duell" <ard.p850ug1 at gmail.com> wrote:

> 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
> parts.

Brilliant, thanks! Nice to see what a clean unit looks like too, mine looks
like it's been in the wars.

I'm back from a little break to see my Missus so I'll clean up the board and
see how bad the damage/rot is.


Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer

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