>From: "Sellam Ismail" <foo_at_siconic.com>
>
>On Thu, 2 Jan 2003, John Lawson wrote:
>
>> On Thu, 2 Jan 2003, Vintage Computer Festival wrote:
>>
>> > I've got the PICK CHECK signal from the reader going into CB2. I have
a
>> > 1K resistor going from CB2 to ground.
>> ^^^^^^^^^^^
>> Try changing to 5K or even 10K (what I always use for pull ups/downs in
>> TTL work. I think you're burying the poor PICK CHECK signal. Actually
>> all the resistors oughta be 10K, IMHO.
>
>I'll certainly try that. But I'm wondering why that should be necessary
>when the 6522 data sheet says that particular pin is a TTL level output.
Hi
I thought you were using the pin as an input. As an input,
there is no pullup and a floating pin would not be good.
Dwight
>
>Sellam Ismail Vintage Computer
Festival
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Received on Thu Jan 02 2003 - 15:17:00 GMT