Re: Repairing a SFD-1001 (8250/LP, 8050, 4040, 3040, 2040)

From: Gerrit Heitsch <>
Date: Mon, 15 Aug 2011 14:39:21 +0200
Message-ID: <>
On 08/14/2011 11:15 PM, Wolfgang Moser wrote:
> Anders, as far as I remember sometime in the past you told that the well
> known dumper programs from William, Olaf and Marko are not able to dump
> the RRIOT ROM and probably the DOS ROMs too from your DOS-1 equipped
> floppy. Did you ever find out what cases this inability? I am willing to
> try to fix my dumper to get this job done as long as we can find out
> that there is a way that will work in the end.

After reading the datasheet for the 6530 I am wondering if no one ever 
has built a small circuit to hook up to the user port of a C64 and dump 
the ROM of a 6530 that way. The circuit could be relatively simple, 
using a MC14040 (12bit binary counter) as the counter for the address 
lines plus maybe some glue logic to adjust polarity of the reset signal 
for the counter and control of the chip selects for the 6530.

The data lines of the 6530 would be connected to PB0-PB7 on the user 
port and the clock input for the counter to PA2.


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Received on 2011-08-15 13:00:18

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