Date   : Sat, 03 Jan 2015 11:57:41 +0000
From   : bbcmicro@... (Wookie)
Subject: Off Topic: problems with my Risc PC

On 03/01/15 00:42, Michael Foot wrote:
> Try swapping the RAM and removing the VRAM. The green screen indicates all
> the basic tests passed, but maybe there is a RAM issue stopping it from
> continuing. The ROMs and CPU appear to be working.

Already tried swapping the RAM around, first trying one stick then 
another and in the other slot, but no joy. With no RAM in I get a light 
blue screen, so I think that means the RAM is okay.

There is no VRAM in the machine, It's a Viewfinder machine, but at the 
moment that is removed as well as the backplane and the network 
interface, so I'm just trying to get a picture from the original VGA out.

> Also try unplugging the hard drive and also booting with Shift held down (to
> bypass the boot sequence).

Harddisc and cdrom drive removed, just the floppy so I can get the 
error-code that isn't happening.

My spare SVGA monitor keeps blowing it's internal fuse so that's off to 
the tip today, I'll have to get another monitor from somewhere to try.

The TV I've been trying to use can sync the following ...

  640 x  400 @ 70
  640 x  480 @ 60 and 75
  800 x  600 @ 60 and 75 and 85
  852 x  480 @ 60
1024 x  768 @ 60 and 70 and 75 and 85
1280 x  768 @ 60
1280 x 1024 @ 60
1366 x  768 @ 60

I'd have thought 640 x 480 @ 60 is doable for a RiscPc with no VRAM.

Cheers
Howard
-- 
The problem with America is stupidity. I'm not saying there should be a 
capital punishment for stupidity, but why don't we just take the safety 
labels off of everything and let the problem solve itself?