Re: ROM Dump of Amiga Keyboard controller

From: Gerrit Heitsch <gerrit_at_laosinh.s.bawue.de>
Date: Sat, 28 Jun 2014 19:12:08 +0200
Message-ID: <53AEF768.2070906@laosinh.s.bawue.de>
On 06/27/2014 02:15 AM, Kajtár Zsolt wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
>> As before, I still don't have a clear picture of how exactly is this
>> supposed to work. Either this or the (presumably simpler) approach with
>> an EPROM and a 4040. I think I am not alone in this and that is one of
>> the reasons nobody (including myself) haven't done it yet.
>
> It works the same way as the EPROW+counter approach. Except that the external
> 6502 is the "counter" for addressing the EPROM. Which has the benefit of
> inserting dummy fetches automatically to the bus when needed. This way you
> could use any assembler/monitor to produce the code for the EPROM, without
> tricks. And this 6502 could be used for the communication with the 6500/1 to
> dump it's content too.

An idea worth thinking about. You still have that clock divided by 2 
problem though and have to make sure somehow that the two 6502 are not 
off by half a cycle.

  Gerrit



       Message was sent through the cbm-hackers mailing list
Received on 2014-06-28 18:01:15

Archive generated by hypermail 2.2.0.