Re: Commodore 128 Startup advice

Date: Wed, 08 Mar 2017 17:26:32 +0100
Message-ID: <>

I'm a bit confused. First you say the C128 boots fine in 128, 40 
column config, then you say it won't, that is, from cold.

You didn't mention the 80 columns screen at all so I can assume you 
are talking only about the 40 columns mode.

My first problem: I got my experience for repairing computers by 
using the try and error method. The actual problem: I hardly ran 
into brooken C128s. The most common failures: RAM and CIAs, and in 
one occasion a ROM.

It boots fine in C64 mode so we can rule out the first 64 KB of RAM 
anyway. If possible, swap the banks and see if it boots fine in C64 
again. If so, you can rule out the RAM. If not possible, the C128 
uses the second bank for BASIC and IMHO won't affect the boot 

Recapping is not needed IMHO as bad capacitors cause problems 
randomly, not just at boor up.

Once booted up in garbage, have you tried to enter commands like 
DIRECTORY? If it is just a screen problem, the drive should start to 
rotate. One thing you can do is to replace the CIA serving the IEC 
bus and userport. If you don't have an extra CIA, swap the two on 
the board. And then boot the computer.

The boot problems could be caused by a flaky ROM. Whatever you have, 
replace the for sure. (easy for me to say because I have tons of 
them laying around).

Just trywith what I gave and let me know what happened.

Kind regards / Met vriendelijke groet, Ruud Baltissen

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Received on 2017-03-08 17:00:02

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