RBIL61 - PORT 03D8-03DF - COLOR VIDEO - CRT MODE AND STATUS REGISTERS

PORTIBM PC Portable (uses same BIOS as XT) 03D8-03DF - COLOR VIDEO - CRT MODE AND STATUS REGISTERS

03D8  RW  CGAColor Graphics Adapter(Color/Graphics Adapter) One of the two video display boards introduced together with the original IBMInternational Busiuness Machines PCIBM PC.  See also HGC, MDA. mode control register  (except PCjr) (see #P0817)
	cannot be found on native color EGAEnhanced Graphics Adapter(Enhanced Graphics Adapter) IBMInternational Busiuness Machines's second color video board for the IBMInternational Busiuness Machines PCIBM PC family, capable of a maximum resolution of 640x350 pixels in 16 simultaneous colors of a total of 64 possible colors., color VGAVideo Graphics Array(Video Graphics Array) The video adapter introduced with the IBMInternational Busiuness Machines PS/2IBM PS/2, any model series of computers., but on most clones
03D9  RW  CGAColor Graphics Adapter(Color/Graphics Adapter) One of the two video display boards introduced together with the original IBMInternational Busiuness Machines PCIBM PC.  See also HGC, MDA. palette register (see #P0819)
	(MCGAMulti-Color Graphics Array(Multi-Color Graphics Array) The low-end color adapter offered in IBMInternational Busiuness Machines's early PS/2IBM PS/2, any model series machines.) CGAColor Graphics Adapter(Color/Graphics Adapter) One of the two video display boards introduced together with the original IBMInternational Busiuness Machines PCIBM PC.  See also HGC, MDA. border control register
	Cannot be found on native EGAEnhanced Graphics Adapter(Enhanced Graphics Adapter) IBMInternational Busiuness Machines's second color video board for the IBMInternational Busiuness Machines PCIBM PC family, capable of a maximum resolution of 640x350 pixels in 16 simultaneous colors of a total of 64 possible colors., VGAVideo Graphics Array(Video Graphics Array) The video adapter introduced with the IBMInternational Busiuness Machines PS/2IBM PS/2, any model series of computers. (without translation ROM(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs.) but
	  only most clones. Read access on Genoa SuperEGA is 'reset'???
03DA  R-  CGAColor Graphics Adapter(Color/Graphics Adapter) One of the two video display boards introduced together with the original IBMInternational Busiuness Machines PCIBM PC.  See also HGC, MDA. status register (see #P0818)
	color EGAEnhanced Graphics Adapter(Enhanced Graphics Adapter) IBMInternational Busiuness Machines's second color video board for the IBMInternational Busiuness Machines PCIBM PC family, capable of a maximum resolution of 640x350 pixels in 16 simultaneous colors of a total of 64 possible colors./VGAVideo Graphics Array(Video Graphics Array) The video adapter introduced with the IBMInternational Busiuness Machines PS/2IBM PS/2, any model series of computers.: input status 1 register
03DA  -W  color EGAEnhanced Graphics Adapter(Enhanced Graphics Adapter) IBMInternational Busiuness Machines's second color video board for the IBMInternational Busiuness Machines PCIBM PC family, capable of a maximum resolution of 640x350 pixels in 16 simultaneous colors of a total of 64 possible colors./color VGAVideo Graphics Array(Video Graphics Array) The video adapter introduced with the IBMInternational Busiuness Machines PS/2IBM PS/2, any model series of computers. feature control register (see #P0820)
	(at PORTIBM PC Portable (uses same BIOS as XT) 03BAh w in mono mode, VGAVideo Graphics Array(Video Graphics Array) The video adapter introduced with the IBMInternational Busiuness Machines PS/2IBM PS/2, any model series of computers.: 3CAh r)
03DA  -W  HZ309 (MDA(Monochrome Display Adapter) A text-only video adapter introduced together with the original IBMInternational Busiuness Machines PCIBM PC.  See also CGAColor Graphics Adapter, HGC./HGC(Hercules Graphics Card) A monochrome video adapter capable of 720x352 monochrome graphics.	 The HGC was the first non-IBM video adapter for the IBMInternational Busiuness Machines PCIBM PC.	 See also CGAColor Graphics Adapter, MDA./CGAColor Graphics Adapter(Color/Graphics Adapter) One of the two video display boards introduced together with the original IBMInternational Busiuness Machines PCIBM PC.  See also HGC, MDA. clone) card from in Heath/Zenith HZ150 PCIBM PC
	bit7-1=0: unknown, zero is default and known to function
		   properly at least in CGAColor Graphics Adapter(Color/Graphics Adapter) One of the two video display boards introduced together with the original IBMInternational Busiuness Machines PCIBM PC.  See also HGC, MDA. modes.
	bit 0 = 1 override 3x8h bit3 control register that switches
		   CRT beam off if bit3 is cleared. So screens always
		   stays on.
	bit 0 = 0 3x8h bit3 indicates if CRT beam is on or off.
		   No more info available. Might conflict with EGAEnhanced Graphics Adapter(Enhanced Graphics Adapter) IBMInternational Busiuness Machines's second color video board for the IBMInternational Busiuness Machines PCIBM PC family, capable of a maximum resolution of 640x350 pixels in 16 simultaneous colors of a total of 64 possible colors./VGAVideo Graphics Array(Video Graphics Array) The video adapter introduced with the IBMInternational Busiuness Machines PS/2IBM PS/2, any model series of computers..
03DB  rW  clear light pen latch	(not MCGAMulti-Color Graphics Array(Multi-Color Graphics Array) The low-end color adapter offered in IBMInternational Busiuness Machines's early PS/2IBM PS/2, any model series machines.)
		  (R/W only with Genoa SuperEGA)
03DC  RW  (not MCGAMulti-Color Graphics Array(Multi-Color Graphics Array) The low-end color adapter offered in IBMInternational Busiuness Machines's early PS/2IBM PS/2, any model series machines.) preset light pen latch
03DC  -W  (CGAColor Graphics Adapter(Color/Graphics Adapter) One of the two video display boards introduced together with the original IBMInternational Busiuness Machines PCIBM PC.  See also HGC, MDA.) set light pen latch
03DD  -W  (MCGAMulti-Color Graphics Array(Multi-Color Graphics Array) The low-end color adapter offered in IBMInternational Busiuness Machines's early PS/2IBM PS/2, any model series machines.)  Extended mode control register
	  (Plantronics & Genoa SuperEGA: Plantronics ColorPlus control,
		      compatible with MCGAMulti-Color Graphics Array(Multi-Color Graphics Array) The low-end color adapter offered in IBMInternational Busiuness Machines's early PS/2IBM PS/2, any model series machines.???)
	(default is 00h, in mode 13h: 04h)
	bit7 =1: DAC(Digital-to-Analog Converter) A hardware device (in its simplest form, nothing more than a set of interconnected resistors) which converts a digital number into an analog signal whose voltage is proportional to the value of the digital number.  VGAVideo Graphics Array and later color video boards use DACs to convert color values into the analog signals sent to the display; sound boards normally use DACs as well. active, cannot be read
	     =0: DAC(Digital-to-Analog Converter) A hardware device (in its simplest form, nothing more than a set of interconnected resistors) which converts a digital number into an analog signal whose voltage is proportional to the value of the digital number.  VGAVideo Graphics Array and later color video boards use DACs to convert color values into the analog signals sent to the display; sound boards normally use DACs as well. not active, read allowed
	bit6-5 : reserved
	bit4   : AST_PLANTRONICS
	bit3   : reserved
	bit2 =1: videomode 13h with 256 colors active
	bit1	: reserved
	bit0 =0: reserved
     	Note:	Apparently on the AST "ColorGraphPlus", its Enhanced mode can
		  be activated with 90h and reset with 00h; on this card the
		  Plantronics mode can be enabled with 10h.
03DE  --  (MCGAMulti-Color Graphics Array(Multi-Color Graphics Array) The low-end color adapter offered in IBMInternational Busiuness Machines's early PS/2IBM PS/2, any model series machines.) reserved
03DE  -W  (AT&TAmerican Telephone and Telegraph & color ET4000 in AT&TAmerican Telephone and Telegraph compatibility mode & C&T 82C426)
	  AT&TAmerican Telephone and Telegraph mode control register (see #P0821)
	(register enabled in ET4000, if bit7=1 in CRTC 3D4h/34h.)
03DF  --  (MCGAMulti-Color Graphics Array(Multi-Color Graphics Array) The low-end color adapter offered in IBMInternational Busiuness Machines's early PS/2IBM PS/2, any model series machines.) reserved
03DF  ?W  CRT/CPU(Central Processing Unit) The microprocessor which executes programs on your computer. page register	 (PCjr only)


Bitfields for CGAColor Graphics Adapter(Color/Graphics Adapter) One of the two video display boards introduced together with the original IBMInternational Busiuness Machines PCIBM PC.  See also HGC, MDA./Hercules mode control register:
Bit(s)	Description	(Table P0817)
 7-0	=A0h color ET4000: second part of 'key', see Hercules compatibility
	  register (see PORTIBM PC Portable (uses same BIOS as XT) 03BFh) for details. For resetting the key, e.g.
	  write 01h to PORTIBM PC Portable (uses same BIOS as XT) 03BFh and 29h to PORTIBM PC Portable (uses same BIOS as XT) 03D8h.
 7	(Hercules) page select
	=0 B0000h
	=1 B8000h
 6	color ET4000 only, read-only: report status of bit 1 (enable 2nd page)
	  of hercules compatibility register (see PORTIBM PC Portable (uses same BIOS as XT) 03BFh)
 5	=1  blink enabled instead of foreground high-int.
 4	=1  640*200 graphics mode (CGAColor Graphics Adapter(Color/Graphics Adapter) One of the two video display boards introduced together with the original IBMInternational Busiuness Machines PCIBM PC.  See also HGC, MDA.)
 3	=1  video enabled (HZ309, see PORTIBM PC Portable (uses same BIOS as XT) 03DAh bit 0)
 2	=1  monochrome signal
		(MCGAMulti-Color Graphics Array(Multi-Color Graphics Array) The low-end color adapter offered in IBMInternational Busiuness Machines's early PS/2IBM PS/2, any model series machines.) in mode 6 and 11h color comes from palette
		  regs 00 (black) and 07 (white), and can be changed there.
 1	=0  text mode
	=1  320*200 graphics mode
 0	text columns (0 = 40*25 text mode, 1 = 80*25 text mode)
SeeAlso: #P0818


Bitfields for CGAColor Graphics Adapter(Color/Graphics Adapter) One of the two video display boards introduced together with the original IBMInternational Busiuness Machines PCIBM PC.  See also HGC, MDA. status register:
Bit(s)	Description	(Table P0818)
 7-6	not used
 7	(C&T Wingine) vertical sync in progress (if enabled by XR14)
 5-4	color EGAEnhanced Graphics Adapter(Enhanced Graphics Adapter) IBMInternational Busiuness Machines's second color video board for the IBMInternational Busiuness Machines PCIBM PC family, capable of a maximum resolution of 640x350 pixels in 16 simultaneous colors of a total of 64 possible colors., color ET4000, C&T: diagnose video display feedback, select
	  from color plane enable
 3	in vertical retrace
	(C&T Wingine) video active (retrace/video selected by XR14)
 2	(CGAColor Graphics Adapter(Color/Graphics Adapter) One of the two video display boards introduced together with the original IBMInternational Busiuness Machines PCIBM PC.  See also HGC, MDA.,color EGAEnhanced Graphics Adapter(Enhanced Graphics Adapter) IBMInternational Busiuness Machines's second color video board for the IBMInternational Busiuness Machines PCIBM PC family, capable of a maximum resolution of 640x350 pixels in 16 simultaneous colors of a total of 64 possible colors.) light pen switch is off
	(MCGAMulti-Color Graphics Array(Multi-Color Graphics Array) The low-end color adapter offered in IBMInternational Busiuness Machines's early PS/2IBM PS/2, any model series machines.,color ET4000) reserved (0)
	(VGAVideo Graphics Array(Video Graphics Array) The video adapter introduced with the IBMInternational Busiuness Machines PS/2IBM PS/2, any model series of computers.) reserved (1)
 1	(CGAColor Graphics Adapter(Color/Graphics Adapter) One of the two video display boards introduced together with the original IBMInternational Busiuness Machines PCIBM PC.  See also HGC, MDA.,color EGAEnhanced Graphics Adapter(Enhanced Graphics Adapter) IBMInternational Busiuness Machines's second color video board for the IBMInternational Busiuness Machines PCIBM PC family, capable of a maximum resolution of 640x350 pixels in 16 simultaneous colors of a total of 64 possible colors.) positive edge from light pen has set trigger
	(VGAVideo Graphics Array(Video Graphics Array) The video adapter introduced with the IBMInternational Busiuness Machines PS/2IBM PS/2, any model series of computers.,MCGAMulti-Color Graphics Array(Multi-Color Graphics Array) The low-end color adapter offered in IBMInternational Busiuness Machines's early PS/2IBM PS/2, any model series machines.,color ET4000) reserved (0)
 0	horizontal retrace in progress
	=0  do not use memory
	=1  memory access without interfering with display
	    (VGAVideo Graphics Array(Video Graphics Array) The video adapter introduced with the IBMInternational Busiuness Machines PS/2IBM PS/2, any model series of computers.,Genoa SuperEGA) horizontal or vertical retrace
	(C&T Wingine) display enabled (retrace/DE selected by XR14)
SeeAlso: #P0817,#P0819,#P0762


Bitfields for CGAColor Graphics Adapter(Color/Graphics Adapter) One of the two video display boards introduced together with the original IBMInternational Busiuness Machines PCIBM PC.  See also HGC, MDA. palette register:
Bit(s)	Description	(Table P0819)
 7-6	not used
 5	=0 active 320x200x4 color set: red, green brown
	=1 active 320x200x4 color set: cyan, magenta, white
 4	intense colors in graphics, background colors text
 3	intense border in 40*25, intense background in 320*200, intense
	  foreground in 640*200
 2	red border in 40*25, red background in 320*200,	red foreground in
	  640*200
 1	green border in 40*25, green background in 320*200, green foreground
	  in 640*200
 0	blue border in 40*25, blue background in 320*200, blue foreground in
	   640*200
SeeAlso: #P0817,#P0818


Bitfields for color EGAEnhanced Graphics Adapter(Enhanced Graphics Adapter) IBMInternational Busiuness Machines's second color video board for the IBMInternational Busiuness Machines PCIBM PC family, capable of a maximum resolution of 640x350 pixels in 16 simultaneous colors of a total of 64 possible colors./VGAVideo Graphics Array(Video Graphics Array) The video adapter introduced with the IBMInternational Busiuness Machines PS/2IBM PS/2, any model series of computers. feature control register:
Bit(s)	Description	(Table P0820)
 7	ET4000 only: enable NMIsee Non-Maskable Interrupt generation ('key' protected)
 6-4	not used
 3	(VGAVideo Graphics Array(Video Graphics Array) The video adapter introduced with the IBMInternational Busiuness Machines PS/2IBM PS/2, any model series of computers.) 0 = normal vsync, 1 = vsync OR display enable
 2	reserved (0)
	(C&T Wingine) disable 16-bit operations
 1	(EGAEnhanced Graphics Adapter(Enhanced Graphics Adapter) IBMInternational Busiuness Machines's second color video board for the IBMInternational Busiuness Machines PCIBM PC family, capable of a maximum resolution of 640x350 pixels in 16 simultaneous colors of a total of 64 possible colors.,ET4000,Wingine) FEAT1 control bit1 (pin17 feature connector)
	(VGAVideo Graphics Array(Video Graphics Array) The video adapter introduced with the IBMInternational Busiuness Machines PS/2IBM PS/2, any model series of computers.) reserved (0)
 0	(EGAEnhanced Graphics Adapter(Enhanced Graphics Adapter) IBMInternational Busiuness Machines's second color video board for the IBMInternational Busiuness Machines PCIBM PC family, capable of a maximum resolution of 640x350 pixels in 16 simultaneous colors of a total of 64 possible colors.,ET4000,Wingine) FEAT0 control bit0 (pin19 feature connector)
	(VGAVideo Graphics Array(Video Graphics Array) The video adapter introduced with the IBMInternational Busiuness Machines PS/2IBM PS/2, any model series of computers.) reserved (0)
SeeAlso: #P0818


Bitfields for AT&TAmerican Telephone and Telegraph mode control register:
Bit(s)	Description	(Table P0821)
 7	reserved
 6	underline color attribute enable
	ET4000: enabled, if bit6=1 in CRTC 3D4h/34h.
 5	reserved
 4	reserved
 3	alternate page select (=1: 2nd 16KB page, with bit0=0)
 2	alternate font select (0=default font block)
 1	reserved
 0	double scan line mode (0=IBMInternational Busiuness MachinesInternational Busiuness Machines) A hardware, software and other service technology company founded in 1911. 200, 1=AT&TAmerican Telephone and Telegraph 400 line graphics)
	(ET4000) enabled, if bit7-6=11b in CRTC 3D4h/34h.