Re: Could you make a 'new', 'better' computer from the C64 just by reprogramming the PLA?

From: smf <smf_at_null.net>
Date: Thu, 4 Nov 2021 08:57:53 +0000
Message-ID: <fd52df67-a392-1835-d8cb-642d3972d0b9_at_null.net>
Their options were.

1. 64k slow dram + a single cheap static ram (which might have been free
at one point as they had a surplus from the pet).

2. faster/more expensive 64k dram & vic 2 with double the clock speed
(more heat/more failures etc), so that it could fetch the font/bitmap
and the color on alternate cycles.

3. more expensive vic 2 that stores the color as well as the characters
in a buffer, which would waste another 1/8th of the cpu (this is the
approach that the ted machines used).

You probably shouldn't question someones decisions if you don't
understand the reason why they made them.

"Tinkering with the address decoding logic" cannot do anything to get
rid of the static ram.


On 03/11/2021 21:37, Claudio Sánchez wrote:
>
> I think that was a solution of compromise so they could stop tinkering
> with the address decoding logic. Why should it be a problem to have
> color RAM mapped in DRAM in the first place? They had to include a
> SRAM chip in *every* computer (later revisions would have it included
> in that SHARP chip).
>
Received on 2021-11-04 10:00:02

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