Re: VIC-II DRAM refresh

From: Francesco Messineo <>
Date: Fri, 14 Oct 2016 15:40:26 +0200
Message-ID: <>
On Fri, Oct 14, 2016 at 3:36 PM,  <> wrote:
>> On 2016-10-14, at 15:24, Francesco Messineo <> wrote:

>> that's even stranger than what I've seen on the C64!
>> I have some suspects that the faster CIAs (6526A/B) sometimes have
>> problems on some
>> C64 revisions, but I've never been able to find a correlation on my
>> limited set of boards.
>> I've seen stock C64Cs coming with 6526B installed from factory anyway.
>> Perhaps the A2000 wants a -A or -B speed grade and can't work with the old 6526?
> A2000 (and other Amigas) uses the 8520 CIAs. I eventually solved the case, but I had to call the guy and tell him that I was sorry but his machine is so much of an atypical case that it needs to be given extra attention at later time and it had no chance to be ready as scheduled. We became good friends for years when I eventually repaired his machine and told him the full story.

isn't the 8520 a 6526A (or B?) but made with a different process? I
could use the 8520 in place of the 6526 with no problems once.

Also the 85-- version of the 6510 works fine in place of the original
(and vice-versa that I could tell).

       Message was sent through the cbm-hackers mailing list
Received on 2016-10-14 14:00:59

Archive generated by hypermail 2.2.0.