Unknown Apple 2 cards - test-drb@ccmp.vtda.org

5 Jun 2003

Hello Jules,

...
  ZIF-socketed card ("unknown_04.jpg" on the
website):  The ZIF socket
 is a 28-pin unit. I'd say it was a programmer, but wouldn't it need
 an external 24V (??) supply if that were true? 
Looks like the Vpp generator is on the far right below the multiturn
pot. It will be something like TL497.

...
  The 40-pin chip is marked as "S6821P",
whatever one of those is. 
68xx series paralell I/O chip.

...
  The first 3 of the switches are labelled as
'16', the next 3
 as '32' and the last 4 (overlapping by 1 with the previous 3) as '64'.

First three on for 2716, next 3 on for 2732 and the last 4 on for 2764.

...
  Card with 8 LEDs and 4 empty 16-pin DIL sockets
("unknown_02.jpg" on the
 website): Any ideas? 
Looks like a digital I/O card. The 6522s are also paralell I/O chips.
Leads to the outside world would plug into the DIL sockets.

Cheers,
	Lee.

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