Re: CBM720 heads up

From: A. Fachat <afachat_at_gmx.de>
Date: Sun, 26 Oct 2014 21:38:20 +0100
Message-ID: <6902544.pc28lLr9H1@euler>
Hi,

On Sunday 19 October 2014 21:21:22 you wrote:
> Hi Andre,
> on your pictures it looks like you built something to generate the 50 Hz
> square signal, so the signal is there ?

Yes, I built a small 555-based circuit for that.

> My CBM 700 sometimes shows the cursor and does not start up.
> Wiggling a bit at the eprom adapters helps.
> The rom sockets are bad, I have to replace them.
> Maybe your roms have contact problems too.
> Try removing the basic roms, the machine schould then start into the TIM
> monitor.

Thanks, that was a good tip. Now I can boot into the monitor and even enter 
commands. 

However, there seem to be some display addressing problems. Parts of the 
screen are displayed twice (each 256 bytes). You can, however, enter commands 
into the screen when in the "overwritten" area, and execute them. So to me it 
looks like it's a screen addressing problem.

https://www.flickr.com/photos/afachat/sets/72157647798386959/

André



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Received on 2014-10-26 21:01:55

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