Re: Unusual Apple // card

[John L <jlogo@zip.com.au>]

On Sat, 23 Mar 2002 01:21:42 +1200, dempson@actrix.gen.nz (David
Empson) wrote:

>John L <jlogo@zip.com.au> wrote:
>
>The 6821 is a PIA (Peripheral Interface Adaptor), which is a simple I/O
>chip providing two 8-bit parallel I/O ports (with the ability to
>configure each pin as either an input or output) and four handshake
>signals (two for each parallel port).
>
>> I have a picture at this URL (A bit unclear) if anyone wants a look:
>> 
>> http://www.zip.com.au/~jlogo/microw.jpg
>
>Any chance you could get a picture from close, and directly above the
>card?

Yes, I've taken a few more shots which can be viewed at this URL:

http://www.zip.com.au/~jlogo/mwcard.jpg
http://www.zip.com.au/~jlogo/mwleft.jpg
http://www.zip.com.au/~jlogo/mwright.jpg

>I can't see any obvious connectors.  What is the white chip on the right
>edge?  (I expect it is the EPROM.)  The components in the top left
>corner may also be of interest.

See the second picture URL posted above.

>Do any of the small ICs have numbers which _don't_ start with 74LS?  I
>see what look like two 8 pin chips.  What are their part numbers?

Ok, looking at the board closely I see  MC14669B  CA3140E DM7408N.
The rest are largely 74LS series chips.  The EPROM has a blue jumper
sitting next to it.   One can also see a three pin connector next to
the EPROM (see picture #3).

>Is there anything which looks like a crystal, and if so, can you see its
>speed rating?

No crystal that I can see.  The picture(s) might help here.




John