Re: Re: Flashing C64 kernal with Nicolas Welte's Universal 6502 RAM/ROM Expansion

From: Niklas Ramsberg <niklas.ramsberg_at_gmail.com>
Date: Sat, 6 Mar 2021 14:29:33 +0100
Message-ID: <CAB7bzfc+3anLJkEwhCBrqmr0V-KkDE6viDVbn+xzYpWeFsmE_w_at_mail.gmail.com>
Hi Nicolas,

Nice to see that you're still here!

Den lör 6 mars 2021 11:49Nicolas Welte <no_spam_at_x1541.de> skrev:

> This means, the Flash is visible in the $A000-$FFFF area only, and the
> part from $8000-$9FFF is always hidden from the 6502 CPU.
>
> The Flash is mapped 32kB at a time into the upper 32kB of the VIC-20, but
> with only the area visible as described above. So you lose 8kB of the 32kB
> per selected bank.
>

So if I configure the VIC adapter for four different kernals I should be
able to flash three and just never switch in the empty lowest 8k. That
would work for me; I only really need two different kernals, at most three.


> For this reason I never used the VIC-20 or the PET to flash generic
> images. I used the 1541 instead, because it has all 32kB visible and I also
> added a connection for "auto-switching" the banks, so I could flash an
> 128kB file in one part. Also this was very fast, because flashing was done
> completely inside the 1541 without transferring data via the slow serial
> bus to the computer first.
>

Yes, that would of course expand my options, but the VIC version will do
for now :)

/Niklas
Received on 2021-03-06 15:00:02

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