Re: Differences between 8501R1 and 8501R4

From: Frank Wolf <webmaster_at_frank-wolf.org>
Date: Thu, 5 Dec 2019 13:16:01 +0100
Message-ID: <2e67ccfd-e564-cffe-ef03-8efd74885237_at_frank-wolf.org>
On 05/12/2019 12:59, Gerrit Heitsch wrote:
>
> Well, it's a 6502 core plus some I/O, rated for 2 MHz (will still run 
> at 2.2 MHz though (*)). The closest relatives would be the 8500 in the 
> C64 and then 8502 in the C128.
>
> From the numbering, the 8500 was started first, but I think the 8501 
> came to market first.

Agreed; see below:

I think the time line is something like: 6509 -> 6510 -> 7501 -> 8501 -> 
8500 or 8502.

The 6509 and 6510 have their sync pad logic moved from the left to the 
top of the die
and my guess is that 6509 just came before the 6510 just because of the 
numbering.

The 8501 still contains some left overs of the SYNC at the top where the 
bias generator
now resides. Therefore I guess that it came first or at the same time as 
the 8500
jsut has some wires removed or cut (compared to the 8501). 8502 might 
just be another
bond-out of the 8500 die... but I haven't seen shots yet.
Received on 2020-05-29 23:43:33

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