-- 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