BBS: Inland Empire Archive
Date: 12-15-92 (13:58) Number: 234
From: ERIC B. FORD Refer#: NONE
To: SCOTT WUNSCH Recvd: NO
Subj: 256 colors in 16 Conf: (2) Quik_Bas
> EBF> I know that. I mean how do you make the screen
> flicer fast enough? You
> EBF> can't redraw it. You can't practically have
> every other line flicker the
> EBF> screen. Must be some interrupt?
> Draw the red part of each pixel on page #1, green on
> #2, blue #3. Then just switch the vpage between the
> three quickly. Normally, this would just entail a
> simple SCREEN ,,,1 and so on. However, since we would
> have to use mode X in order to get 256 with multiple
> pages, it must be done by calling an interrupt,
> telling the card to change pages.
Right that's what I'm saying. No one is going to have half
their program switching the page. There must be an
interrupt. BUT WHERE??? WHAT??? HOW??? I got this thing
on VGA interrupts, (below) but I can't find what I'm
looking for.
Current video mode = 03
Sequencer registers:
-----------------------------------------------
0h: 03h 3 :Reset
1h: 00h 0 :Clocking mode
2h: 03h 3 :Map mask
3h: 00h 0 :Character map select
4h: 02h 2 :Memory mode
Miscellaneous output register
: 67h :
CRTC data register contents:
-----------------------------------------------
0h: 5fh 95 :Horizontal total (+5= 100)
1h: 4fh 79 :Horizontal display enable end
2h: 50h 80 :Start horizontal blanking
3h: 82h 130 :End horizontal blanking (= 98)
4h: 55h 85 :Start horizontal retrace
5h: 81h 129 :End horizontal retrace (= 97)
6h: bfh 191 :Vertical total (= 447)
7h: 1fh 31 :Overflow
: Bit 9 :0 - Vertical Retrace start
: Bit 9 :0 - Vertical Display enable end
: Bit 9 :0 - Vertical Total
: Bit 8 :1 - Line compare
: Bit 8 :1 - Start vertical blank
: Bit 8 :1 - Vertical Retrace start
: Bit 8 :1 - Vertical Display enable end
: Bit 8 :1 - Vertical Total
8h: 00h 0 :Preset row scan
9h: 4fh 79 :Maximum scan line address (= 15)
: :double scan set to 0
ah: 0dh 13 :Cursor start
bh: 0eh 14 :Cursor end
ch: 00h 0 :Start address high
dh: 00h 0 :Start address low
eh: 07h 7 :Cursor location high
fh: 80h 128 :Cursor location low
10h: 9ch 156 :Vertical retrace start (= 412)
11h: 8eh 142 :Vertical retrace end (= 414)
: :CRTC registers 0 to 7 write protected.
: :Refresh Cycle Select=0
: :(not)Enable vertical interrupt=0
: :(not)Clear vertical interrupt=0
12h: 8fh 143 :Vertical display enable end (= 399)
13h: 28h 40 :Offset (logical line width)
14h: 1fh 31 :Underline location (= 31)
: :Double word mode=0
: :Count by 4 mode=0
15h: 96h 150 :Start vertical blanking (= 406)
16h: b9h 185 :End vertical blanking (= 441)
17h: a3h 163 :Mode Control ()
18h: ffh 255 :Line compare ()
Attribute controller registers:
-----------------------------------------------
0h: 00h 0 :Palette color #0
1h: 00h 0 :Palette color #1
2h: 00h 0 :Palette color #2
3h: 00h 0 :Palette color #3
4h: 00h 0 :Palette color #4
5h: 00h 0 :Palette color #5
6h: 00h 0 :Palette color #6
7h: 00h 0 :Palette color #7
8h: 00h 0 :Palette color #8
9h: 00h 0 :Palette color #9
ah: 00h 0 :Palette color #10
bh: 00h 0 :Palette color #11
ch: 00h 0 :Palette color #12
dh: 00h 0 :Palette color #13
eh: 00h 0 :Palette color #14
fh: 00h 0 :Palette color #15
10h: 04h 4 :Attribute mode control
11h: 00h 0 :Border color
12h: 0fh 15 :Color plane enable
13h: 08h 8 :Horizontal pixel panning
14h: 00h 0 :Color select
Graphics controller registers:
-----------------------------------------------
0h: 00h 0 :Set/reset
1h: 00h 0 :Enable set/reset
2h: 00h 0 :Color compare
3h: 00h 0 :Data rotate/function select
4h: 00h 0 :Read map select
5h: 10h 16 :Graphics mode
6h: 0eh 14 :Miscellaneous
7h: 00h 0 :Color don't care
8h: ffh 255 :Bit mask
---
* Origin: Eric Ford (1:3632/1.6)
