-- NNGS.txt
Question: what value for parameter 3 bit 40H IM page 8 ?
x60000-9FFFF 256KB Display buffer (Not Used)
A00000-AFFFF 64K Display buffer
C0000 GDC Write Parameter, Read Status
C0001 GDC Write Command, Read Data
C0100-C01FF 256 Red Look up table
C0200-C02FF 256 Green Look up table
C0300-C03FF 256 Blue Look up table
C0700 3400 FF ZOOM 1 (FF default, 00 more blowup)
C0701 3401 FF ZOOM 2 (FF default, 00 more blowup)
C0702 3402 F ZOOM 4 (FF default, 00 more blowup)
C0703 3403 F ZOOM 8 (FF default, 00 more blowup)
C0704 3404 F MODE (00 plane, FF pixel)
C0705 3405 BANK0
C0706 3406 BANK1
C0707 3407 FF BUS ENABLE ((00 disable, FF enable)
INIT←TABLE DB 01FH 37Q ; standard initialization table
DB 03EH 76Q ; RS170A INTERLACED
DB 064H 144Q ; 512X480 DISPLAY
DB 008H ; 512X512 BIT-PLANE
DB 005H
DB 003H
DB 0F0H 360Q
DB 040H 100Q
PRAM←TABLE DB 000H ; screen parameters
DB 000H ; START DISPLAY AT 0,0
DB 000H
DB 07FH 177Q ;or IMAGE←BIT?
IMAGE←BIT DB 040H 100Q
hex octal page GDC Command Name
--- ----- ---- -----------------
0 0 9 Reset(,,,,,,,)
0C 14Q 10 BCtrlBlank()
0D 15Q 10 BCtrlUnblank()
6F 157Q 10 VSynchMaster()
46 106Q 11 Zoom(DispGChr)
47 107Q 11 Pitch(horizontalWordCount=PixCnt/8)
4A 112Q 12 Mask(MaskL, MaskH)
4B 113Q 10 CChar(,,)
6B 153Q 10 Start()
70 160Q 11 PRam( ... ) ;parameter ram
78 170Q 11 PRam( ... ) ;graphics parameters
Intialization:
Mem(C0704) ← FF, Mem(C0707) ← FF
Reset[0, 1F, 3E, 64H, 8, 5, 3, F0, 40H]
Pitch[047H, 40H]
VSynchMaster[06FH]
Zoom[46H, 0]
Mem(C0700-3) ← FF
CChar[4B, 0, 0C0, 0] ; disable character mode
PRam[70H, 0, 0, 0, 7F(or 3F)] ;screen parameters DISPLAY AT 0,0
PRam[78H, FF,FF,FF,FF, FF,FF,FF,FF ] ; graphics parameters
Mask[4AH, 0FF, 0FF] ; set mask to all 1s
Mem(C0100-C01FF) ← red
Mem(C0200-C02FF) ← green
Mem(C0300-C03FF) ← blue
Start[6BH] ; start the display
BCtrlUnblank[0D]
--------------------------------------------------------
Summary of init.asm:
NNGS ;ENABLE CARD AND PIXEL MODE ACCESS
PIX←DMA
Mem(C0704) ← FF, Mem(C0707) ← FF
RESET(AL) don't wait just do:
Reset[0, 1F, 3E, 64H, 8, 5, 3, F0, 40H]
INIT←PARMS
SET←PITCH
Pitch[047H, 40H] ;set pitch to 512X512 BIT-PLANE
VSynchMaster[06FH] ; set vertical sync
ZOOM
Zoom[46H, ZOOM=0]
FOR i from 0 to 3 do Mem(C0703+i) ← LeftShift(ZOOM, i)
DIS←CHR
CChar[4B, 0, 0C0, 0] ; disable character mode
PAR←RAM
PRam[70H, 0, 0, 0, 7F(or 3F)] ;screen parameters DISPLAY AT 0,0
GRAF←PAR
PRam[78H, FF,FF,FF,FF, FF,FF,FF,FF ] ; graphics parameters
SET←MASK(AX)
Mask[4AH, 0FF, 0FF] ; set mask to all 1s
CLEAR
Mem(C0705) ← 0, Mem(C0705) ← 0, For i = 0 to 0FFFF do Mem(A0000+i) ← 0
Mem(C0705) ←FF, Mem(C0705) ← 0, For i = 0 to 0FFFF do Mem(A0000+i) ← 0
Mem(C0705) ← 0, Mem(C0705) ←FF, For i = 0 to 0FFFF do Mem(A0000+i) ← 0
Mem(C0705) ←FF, Mem(C0705) ←FF, For i = 0 to 0FFFF do Mem(A0000+i) ← 0
RGBW←PAL
STEP←PAL(BX, DI)
PALMOV
VSYNC Memory(C0000:Status) and 020H 0->1
Mem(C0100-C01FF) ← red
Mem(C0200-C02FF) ← green
Mem(C0300-C03FF) ← blue
START←DISP
Start[6BH] ; start the display
UN←BLANK
BCtrlUnblank[0D]
CLR←MSK
SET←MASK [AX: 0FFFF]
BLANK
BCtrlUnblank[0C]
PLANE←DMA
Mem(C0704) ← 0, Mem(C0707) ← FF
OUT←COMD(AL)
Until Mem(C0000) and 2 = 0 wait
Mem(C0001) ← AL
OUT←PAR(AL)
Until Mem(C0000) and 2 = 0 wait
Mem(C0000) ← AL