johnmac@fawlty.towers.oz (John MacLean) (12/21/89)
I got hold of my Video Overlay Card (VOC) a while back and am desperate to get 400 line graphics going (and determine if there are any other modes). Would someone please help! This is what I have worked out so far: $C0B1: NEWNEWVID register %ABCDEFGH D = 1 bank $E0 SHR D = 0 bank $E1 SHR E = 1 standard SHR as we know it today E = 0 weird SHR as described below B = 1 appears to hang machine H = 1 no video output in text mode Wierd SHR: $2000-$9CFF pixel map data as usual $9D00-$9E7F appears to do absolutely nothing $9E80-$9EE3 SCBs for every second SHR line (100 of them) $9EE4-$9EFF appears to do absolutely nothing $9F00-$9FFF 16 palettes, 16 bytes each, only Blue/Green components I have no idea where the Red components of each palette are, or the other SCBs for that matter. I have tried setting the reserved bit in each SCB, and various other bits around $C000. Please help, someone out there must know how to do this ... John MacLean. -- This net: johnmac@fawlty.towers.oz.au Phone: +61 2 427 2999 That net: uunet!fawlty.towers.oz.au!johnmac Fax: +61 2 427 7072 Snail: Tower Technology Unit D 31-33 Sirius Rd, Lane Cove, NSW 2066, Australia.
johnmac@fawlty.towers.oz (John MacLean) (12/27/89)
Just an update, $5E80..$5EE3 contains the other 100 SCBs $5F00..$5FFF contains the 0R components of each palette Anyone know how to get 400 lines yet, (or know anyone who knows!). John Mac. -- This net: johnmac@fawlty.towers.oz.au Phone: +61 2 427 2999 That net: uunet!fawlty.towers.oz.au!johnmac Fax: +61 2 427 7072 Snail: Tower Technology Unit D 31-33 Sirius Rd, Lane Cove, NSW 2066, Australia.