Re: Strange Problem Amiga 2000

From: Gerrit Heitsch <>
Date: Sat, 6 Oct 2018 21:11:32 +0200
Message-ID: <>
On 10/06/2018 08:52 PM, Mia Magnusson wrote:
> Den Sat, 6 Oct 2018 19:52:23 +0200 skrev Francesco Messineo
> <>:
>> On Sat, Oct 6, 2018 at 7:45 PM Gerrit Heitsch
>> <> wrote:
>>> Well, this version is using an early version of the Zorro bus, the
>>> whole logic implemented in PALs and TTLs and not a BUSTER chip as
>>> in the later A2000 where AGNUS came in 84pin PLCC instead of 48pin
>>> DIP. There are some problems with the bus protocol on the Zorro
>>> slots.
> Well, the "protocol" itself is mostly just the autoconfig process,
> which is super simple to implement (and most likely not a problem). The
> problems it might have seems more likely to be of the analogue kind,
> i.e. reflections or similar.
> That might, or might not, be an issuie in your case.

All interesting signals (address, data and some control signals) for the 
Zorro slots have to go through a bunch of 74LS245, so reflections on the 
long traces for the slots can't be the issue.

Received on 2018-10-06 22:00:05

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