Re: a CIA riddle - please run these tests

From: Gerrit Heitsch <gerrit_at_laosinh.s.bawue.de>
Date: Thu, 18 Jun 2020 20:09:52 +0200
Message-ID: <8b7b4a8e-f88d-6d67-8e3f-33e4b72adf4e_at_laosinh.s.bawue.de>
On 6/18/20 7:37 PM, groepaz_at_gmx.net wrote:

> Now run the "delay2-new" and "delay2-old" programs. Green border means "test
> passed", and will generally tell if you have a "new" or "old" CIA. (Contrary
> to popular belief this can NOT be reliably determined from whats written on
> the chip)

So far I was always able to tell what kind of CIA it is by looking at 
the chip.

No, the 'A' after the 6526 is not an indicator.

I do know 3 CIAs though:

6526 (sometimes with 'R4')
8521R0 (also labeled as '6526' with '206A')
8521R1 (labeled 6526 with '216A')

The question is, can you tell the 8521R0 und R1 apart via software? I 
have seen the 8521R1 stamped as '6526B', meaning good for 3 MHz.

  Gerrit
Received on 2020-06-18 21:00:03

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