Re: Commodore 65 and DIN8 cable

From: Michał Pleban <>
Date: Fri, 05 Feb 2016 21:21:02 +0100
Message-ID: <>

A quick update: Today I tried various resistor values between GND and
RDATA to no avail. So I decided the best solution for me would be a
shorter cable. I got a pair of scissors and began to cut the cable into
and shorter parts, while one of its end was still plugged into the C65.
I wrote a simple BASIC program which tries to download the disk
directory 100 times and gives the percentage of successful operations.

Here is the success rate as a function of cable length:

100 mm - 15%
60 mm - 70%
50 mm - 90%
40 mm - 95%
30 mm - 100%

Not bad - with a 30 mm cable I can read the directory reliably. SO to
test things further, I created a 64 kB SQL file, then used the DOS COPY
command to duplicate it, and finally used TYPE to display it on the
screen. All the operations were performed without errors.

So I conclude that a 30 mm cable does not cause any problems with disk
operations. Perhaps it would be best to make it 25 mm just in case - the
signals will also need to go a bit over the PCB and the flat ribbon
cable before they reach the drive.

The big question is now: where can I get a 25 mm mini-DIN8 cable? :-)


       Message was sent through the cbm-hackers mailing list
Received on 2016-02-05 21:00:10

Archive generated by hypermail 2.2.0.