[Coco] Pretty new screen
cwgordon at carolina.rr.com
Fri Mar 6 09:19:35 EST 2009
WOW!! Here is something unusual. I tried today to check out the chips (all
soldered but two), and the only way I could see anything on the screen was
to tune to channel 2 (3 or 4 do not pick anything up). I still have the
screen pictured in the link I gave, but it will ONLY come in on channel 2.
The 2 socketed chips are the SN74LS785N hidden partially under the keyboard,
and the XC80652P (58C8444), just to the right of the RF output.
This is, of course, the 26-3127B Korean Coco2
> -----Original Message-----
> From: coco-bounces at maltedmedia.com [mailto:coco-
> bounces at maltedmedia.com] On Behalf Of afra at aurigae.demon.co.uk
> Sent: Thursday, March 05, 2009 11:58 AM
> To: coco at maltedmedia.com
> Subject: Re: [Coco] Pretty new screen
> Which CoCo model is this ?
> Whilst I agree with Robert who said that it would be impossible to
> tell for certain, the one time I have seen a pattern like that before
> from a Dragon, which is basically the same as the CoCo 1/2, the
> problem was the 74LS244 buffer chip that sits between the processor
> data bus and the RAM/VDG data bus. Said LS chip had died and no data
> was getting writen to the RAM, and so the VDG was just pulling out
> whatever default patern was there.
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