Re: 6529 replacement

From: Gerrit Heitsch <>
Date: Fri, 04 May 2012 23:17:29 +0200
Message-ID: <>
On 05/04/2012 11:06 PM, wrote:
> Hi,
> Is there any way to replace a 6529 by something else ?
> What is it exactly ? a kind of combination of 74LS245 and 74LS373 ?

Sort of...

> Is the port all input or all output ?

The port ist both... If you want to use it as input, you set the port 
bit to '1' (HIGH) and then read it back. If it comes back as '0' (LOW) 
it was pulled low by an external source.

I picture the output stage like a gate of a 7406 plus a pullup resistor.

> What define the mode ? input/output ?

No data direction register.

> I found 8501 + TED and a 6529 but saw a 6529 only once on ebay….

They usually don't die. At least so far I didn't have one fail on me.

> Is there anything that can replace this component ? if not available ?

The 6529 used in the keyboard port of a C16 is only written to, as far 
as I know. So there you might be able to get away with a 74LS574 or 
74LS573 with the pinout adjusted. It'll produce much harder edges than 
that rather soft NMOS 6529 though.


       Message was sent through the cbm-hackers mailing list
Received on 2012-05-04 22:00:09

Archive generated by hypermail 2.2.0.