WTD: support ICs

From: Dwight K. Elvey <dwightk.elvey_at_amd.com>
Date: Tue Jul 30 14:58:01 2002

>From: ard_at_p850ug1.demon.co.uk
>
>>
>> Hi
>> I'm always looking for DTL chips. Finding these
>> would be great. Anyone with some of these hiding
>> away or some old surplus board with them on it,
>> I'd be interested. I forget the numbers I need
>> but one is a open collector nand ( something like
>> 935? but that sounds like a RTL). I'll have to make
>
>It's been a long time, but I thought the 935 was an hex inverter
>(open-collecotr output, of course -- aren't _all_ DTL chips like that).
>The quad 2-input NAND is the 846 (I was repairing a board that used one,
>surrounded by TTL chips, the other day).
>
>Unless the _input_ characteristics are important (they were on this
>board, as the inputs came from RC networks), you can often use the
>equivalent TTL part (open-collector outputs, so something like a '03 for
>the NAND or a '05 for the inverter) with resistor pull-ups (around 3k
>from each output to Vcc). It's not original, but it normally works.
>
>-tony
>
>

Hi Tony
 I think the one number I'm thinking of was something38
and not somthing35. Yes, it is true that a TTL will
sub in most cases but there is one that doesn't work
and that is where you have the expanded input ( also one
of the chips I'm looking for ). This was only done
on the DTL and not supported on the TTL of similar
function.
 I have to go back and look to see what the numbers were.
Dwight
Received on Tue Jul 30 2002 - 14:58:01 BST