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Gentlemen :

I was digging around in some of my REALLY OLD junk and ran across a box that
had all of my saved 8080 based stuff . I ran into one of my old buddies the 8255
. Do they still make this part ? I decided to use this thing to help interface
the 2103 to my 8 bit based projects as I keep running out of pins on the ARMite
to use for control . I think that this may be the solution to the problem as it
has the ability to source / send up to 3 separate 8 bit ports in a MUX/DEMUX
kinda mode .
Apparently this thing is bufferered as well . My question :

As this chip uses the old MICROBUS technology , do any of you guys know of the
actual buffering specs ?

I have used this thing before with everything from the 8080 thru the 88000
series , 6502 , 6505 , 6509 , 6510 and the like with no real problems . I guess
that it is good that I kept some of the IC's from my video/arcade vending days !
Funny that I can't find my old stock of games boards for Galaga , Defender ,
PacMan and the like though .

Don't give up . Rick

> As this chip uses the old MICROBUS technology , do any of you guys know of
the actual buffering specs ?
>

Its possible someone still makes the 8255, but its probably real expensive if
its available.

These days there are SPI or I2C IO expanders of many shapes and sizes, and that
is the best way to add IOs.

Here's the site for the DigiKey order sheet:
http://search.digikey.com/scripts/DkSea ... P82C55A-ND

Just down the page is the data sheet link for Intersil's version. Perhaps that
has the data you seek.
Take care.
KenJ

I used the 8255 extensively back in the 8080/8085/8086 days. I don't recall that
it has any storage space, just three 8 bit I/Os per chip and a programmable
control I/F.

Gentlemen :

Thanx for the advice from Bruce , Ken Jennejohn and Jmrobert .
Great advice boys ! As an old guy getting back into the "mix" I sometimes froget
about some otherwise obvious sources . The newer ones , of course ; come from
you guys .

I did resolve a couple of the issues previously described to a satisfactory
conclusion . Parts sourcing is still kind of a sore spot though . CANADA
apparently is still considered to be a "third world" country as far as shipping
is concerned . Amazing since about 80% of our
population is within 50 miles of the US border ! Only one LINE in between .
We're still the US number 1 trading partner though .

Regards for your guys' efforts . Thanx again for the help !

Rick On your project; Don't Give Up ! EVER . It's too much fun !