Date   : Thu, 30 Jan 1997 23:32:40 -0000
From   : "Kenny & Joanne" <kennyr@...>
Subject: Fw: Fw: BBC computer help requested

There are two main chips which handle the BBC video display. If the error
occurs in Modes 0-6 then have a look at  the 6845 ic (40 pin). If it is Mode
7, then look at the teletext chip. Can't remember the exact number, but it
ends in something like 050. It is off to the right of the 6502 CPU. I will
dig out a circuit diagram and have a look!

Hope this is of some help for now!




-----Original Message-----
From: Mark Usher <marku@...>
To: BBC MICRO Mailing List POSTINGS <bbc-micro@...>
Date: 16 February 1998 14:40
Subject: [BBC-Micro] Fw: BBC computer help requested


>Forwarding a plea for help. I've informed the poor soul that I've forwarded
>the message and that he should subscribe.
>Can anyone suss this ?
>
>Mark Usher
>
>-----Original Message-----
>From: Andrew Davie <adavie@...>
>Newsgroups: comp.sys.acorn.hardware,comp.sys.acorn.misc
>Date: Samstag, 14. Februar 1998 06:30
>Subject: BBC computer help requested
>
>
>>I have just retreived a BBC computer.
>>Seems to work fine, and I have managed to get directories of several of
the
>>(rather warped) 5.25 disks.  I'm extremely surprised any data is readable
>at
>>all - nice looking tandem dual floppy.
>>However, onscreen I see there's a problem with the machine.
>>I see perhaps 1/5th of the screen and then it repeats.  Furthermore, the
>>width of the screen isn't correct... that is, I see 20 or so character
wide
>>lines displaying and thus staircaising.  I suspect its a hardware problem
>>(almost 100% certain here, I've tried software mode changes - same in
every
>>mode), but have nil hardware expertise.
>>So, when (occasionally) i see a > prompt, and type, i see what I type
>>perhaps 20 times in varying places on the screen, each line offset from
the
>>other.
>>Can anyone suggest my first steps to playing with it - what sort of chips
>>should I be looking for, perhaps?
>>I know, I'm behind the 8-ball, but you're all such brilliant guys at
>>restoration, right?
>>Any help much appreciated.
>>Cheers
>>Andrew
>
>
>