PORTIBM PC Portable (uses same BIOS as XT) 02C6-02C9 - 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. - 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. REGISTERS (alternate address)
PORTIBM PC Portable (uses same BIOS as XT) 03B0-03BF - 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. (Monochrome Display Adapter based on 6845)
PORTIBM PC Portable (uses same BIOS as XT) 03BF - Hercules configuration switch register
PORTIBM PC Portable (uses same BIOS as XT) 03C0-03C1 - 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. - ATTRIBUTE CONTROLLER
PORTIBM PC Portable (uses same BIOS as XT) 03C2-03CF - 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. - MISCELLANEOUS REGISTERS
PORTIBM PC Portable (uses same BIOS as XT) 03C6-03C9 - 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./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. - 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. REGISTERS
PORTIBM PC Portable (uses same BIOS as XT) 03CA-03CD - 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./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. - GRAPHICS POSITION
PORTIBM PC Portable (uses same BIOS as XT) 03CE-03CF - 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./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. - GRAPHICS CONTROLLER REGISTERS
PORTIBM PC Portable (uses same BIOS as XT) 03D0-03D3 - 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 Graphics Adapter) - MIRRORS OF 03D4/03D5
PORTIBM PC Portable (uses same BIOS as XT) 03D4-03D5 - COLOR VIDEO - CRT CONTROL REGISTERS
PORTIBM PC Portable (uses same BIOS as XT) 0EE8 - S3 86C928 video controller (ELSA Winner 1000)
PORTIBM PC Portable (uses same BIOS as XT) 0EE8-0EEF - 8514/A and compatible (e.g. ATI Graphics Ultra) - HSYNC WIDTH
PORTIBM PC Portable (uses same BIOS as XT) 12EE - ATI Mach32 - CONFIGURATION STATUS 0
PORTIBM PC Portable (uses same BIOS as XT) 16EE - ATI Mach32 - CONFIGURATION STATUS 1
PORTIBM PC Portable (uses same BIOS as XT) 1C85 - Compaq Qvision EISA(Enhanced Industry-Standard Architecture) A 32-bit superset of the IBMInternational Busiuness Machines ATIBM PC AT's expansion bus (which is now known as the ISA or Industry-Standard Architecture bus). - Virtual Controller ID
PORTIBM PC Portable (uses same BIOS as XT) 1EE8-1EEF - 8514/A and compatible (e.g. ATI Graphics Ultra) - VSYNC WIDTH
PORTIBM PC Portable (uses same BIOS as XT) 1EEC - Mach64 - ???
PORTIBM PC Portable (uses same BIOS as XT) 2100 - XGA(Extended Graphics Array) Video Operating Mode Register
PORTIBM PC Portable (uses same BIOS as XT) 2101 - XGA(Extended Graphics Array) Video Aperture Control
PORTIBM PC Portable (uses same BIOS as XT) 2102-2103 - XGA(Extended Graphics Array) ???
PORTIBM PC Portable (uses same BIOS as XT) 2104 - XGA(Extended Graphics Array) Video Interrupt Enable
PORTIBM PC Portable (uses same BIOS as XT) 2105 - XGA(Extended Graphics Array) Video Interrupt Status
PORTIBM PC Portable (uses same BIOS as XT) 2106 - XGA(Extended Graphics Array) Video Virtual Memory Control
PORTIBM PC Portable (uses same BIOS as XT) 2107 - XGA(Extended Graphics Array) Video Virtual Memory Interrupt Status
PORTIBM PC Portable (uses same BIOS as XT) 2108 - XGA(Extended Graphics Array) Video Aperture Index
PORTIBM PC Portable (uses same BIOS as XT) 2109 - XGA(Extended Graphics Array) Video Memory Access Mode
PORTIBM PC Portable (uses same BIOS as XT) 210A - XGA(Extended Graphics Array) Video Index for Data
PORTIBM PC Portable (uses same BIOS as XT) 210B - XGA(Extended Graphics Array) Video Data (byte)
PORTIBM PC Portable (uses same BIOS as XT) 210C-210F - XGA(Extended Graphics Array) Video Data (word/dword)
PORTIBM PC Portable (uses same BIOS as XT) 2110-211F - IBMInternational Busiuness MachinesInternational Busiuness Machines) A hardware, software and other service technology company founded in 1911. XGA(Extended Graphics Array) (eXtended Graphics Adapter 8514/A) (second installed)
PORTIBM PC Portable (uses same BIOS as XT) 2120-212F - IBMInternational Busiuness MachinesInternational Busiuness Machines) A hardware, software and other service technology company founded in 1911. XGA(Extended Graphics Array) (eXtended Graphics Adapter 8514/A) (third installed)
PORTIBM PC Portable (uses same BIOS as XT) 2130-213F - IBMInternational Busiuness MachinesInternational Busiuness Machines) A hardware, software and other service technology company founded in 1911. XGA(Extended Graphics Array) (eXtended Graphics Adapter 8514/A) (fourth installed)
PORTIBM PC Portable (uses same BIOS as XT) 2140-214F - IBMInternational Busiuness MachinesInternational Busiuness Machines) A hardware, software and other service technology company founded in 1911. XGA(Extended Graphics Array) (eXtended Graphics Adapter 8514/A) (fifth installed)
PORTIBM PC Portable (uses same BIOS as XT) 2150-215F - IBMInternational Busiuness MachinesInternational Busiuness Machines) A hardware, software and other service technology company founded in 1911. XGA(Extended Graphics Array) (eXtended Graphics Adapter 8514/A) (sixth installed)
PORTIBM PC Portable (uses same BIOS as XT) 2160-216F - IBMInternational Busiuness MachinesInternational Busiuness Machines) A hardware, software and other service technology company founded in 1911. XGA(Extended Graphics Array) (eXtended Graphics Adapter 8514/A) (seventh installed)
PORTIBM PC Portable (uses same BIOS as XT) 2170-217F - IBMInternational Busiuness MachinesInternational Busiuness Machines) A hardware, software and other service technology company founded in 1911. XGA(Extended Graphics Array) (eXtended Graphics Adapter 8514/A) (eighth installed)
PORTIBM PC Portable (uses same BIOS as XT) 217A-217B - ET4000/W32 CRTC-B/Sprite
PORTIBM PC Portable (uses same BIOS as XT) 23C0-23CF - Compaq QVision - BitBLT engine
PORTIBM PC Portable (uses same BIOS as XT) 28E9 - 8514/A - WD Escape Functions
PORTIBM PC Portable (uses same BIOS as XT) 2C80-2C8F - VESA(Video Electronics Standards Association) An industry group which sets both hardware and software standards and recommendations. The term VESA is also used to denote compliance with the VESA SuperVGA BIOS Extensions, a standard set of video BIOS functions for accessing video modes of higher resolution than those defined by IBMInternational Busiuness Machines. XGA(Extended Graphics Array) Video in EISA(Enhanced Industry-Standard Architecture) A 32-bit superset of the IBMInternational Busiuness Machines ATIBM PC AT's expansion bus (which is now known as the ISA or Industry-Standard Architecture bus). slot 2
PORTIBM PC Portable (uses same BIOS as XT) 33C0-33CF - Compaq QVision - BitBLT engine
PORTIBM PC Portable (uses same BIOS as XT) 36EE - ATI Mach8/Mach32 - FIFO OPTION
PORTIBM PC Portable (uses same BIOS as XT) 3C80-3C8F - VESA(Video Electronics Standards Association) An industry group which sets both hardware and software standards and recommendations. The term VESA is also used to denote compliance with the VESA SuperVGA BIOS Extensions, a standard set of video BIOS functions for accessing video modes of higher resolution than those defined by IBMInternational Busiuness Machines. XGA(Extended Graphics Array) Video in EISA(Enhanced Industry-Standard Architecture) A 32-bit superset of the IBMInternational Busiuness Machines ATIBM PC AT's expansion bus (which is now known as the ISA or Industry-Standard Architecture bus). slot 3
PORTIBM PC Portable (uses same BIOS as XT) 42E8 - 8514/A and hardware-compatible video cards
PORTIBM PC Portable (uses same BIOS as XT) 42EC - ATI Mach64 - ???
PORTIBM PC Portable (uses same BIOS as XT) 42ED - ATI Mach64 - ???
PORTIBM PC Portable (uses same BIOS as XT) 42EE-42EF - ATI Mach32 - MEMORY BOUNDARY REGISTER
PORTIBM PC Portable (uses same BIOS as XT) 42EF - ATI Mach64 - ???
PORTIBM PC Portable (uses same BIOS as XT) 46E8 - VGAVideo Graphics Array(Video Graphics Array) The video adapter introduced with the IBMInternational Busiuness Machines PS/2IBM PS/2, any model series of computers. - VIDEO ADAPTER ENABLE
PORTIBM PC Portable (uses same BIOS as XT) 46EE - ATI Mach32 - ???
PORTIBM PC Portable (uses same BIOS as XT) 46EF - ATI Mach64 - ???
PORTIBM PC Portable (uses same BIOS as XT) 4AE8-4AE9 - 8514/A and compatible - CRT CONTROL
PORTIBM PC Portable (uses same BIOS as XT) 4AEE - ATI Mach32 - ???
PORTIBM PC Portable (uses same BIOS as XT) 4C80-4C8F - VESA(Video Electronics Standards Association) An industry group which sets both hardware and software standards and recommendations. The term VESA is also used to denote compliance with the VESA SuperVGA BIOS Extensions, a standard set of video BIOS functions for accessing video modes of higher resolution than those defined by IBMInternational Busiuness Machines. XGA(Extended Graphics Array) Video in EISA(Enhanced Industry-Standard Architecture) A 32-bit superset of the IBMInternational Busiuness Machines ATIBM PC AT's expansion bus (which is now known as the ISA or Industry-Standard Architecture bus). slot 4 (see 3C80-3C8F)
PORTIBM PC Portable (uses same BIOS as XT) 52E8-52E9 - C&T 82c480 - EXTENDED CONFIGURATION REGISTER 0
PORTIBM PC Portable (uses same BIOS as XT) 52EE-52EF - ATI Mach32 - SCRATCH REGISTER 0 (USED FOR ROM(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs. LOCATION)
PORTIBM PC Portable (uses same BIOS as XT) 56E8-56E9 - C&T 82c480 - EXTENDED CONFIGURATION REGISTER 1
PORTIBM PC Portable (uses same BIOS as XT) 56EE-56EF - ATI Mach32 - SCRATCH REGISTER 1
PORTIBM PC Portable (uses same BIOS as XT) 5AE8-5AE9 - C&T 82c480 - EXTENDED CONFIGURATION REGISTER 2
PORTIBM PC Portable (uses same BIOS as XT) 5AEE - ATI Mach32 - ???
PORTIBM PC Portable (uses same BIOS as XT) 5C80-5C8F - VESA(Video Electronics Standards Association) An industry group which sets both hardware and software standards and recommendations. The term VESA is also used to denote compliance with the VESA SuperVGA BIOS Extensions, a standard set of video BIOS functions for accessing video modes of higher resolution than those defined by IBMInternational Busiuness Machines. XGA(Extended Graphics Array) Video in EISA(Enhanced Industry-Standard Architecture) A 32-bit superset of the IBMInternational Busiuness Machines ATIBM PC AT's expansion bus (which is now known as the ISA or Industry-Standard Architecture bus). slot 5
PORTIBM PC Portable (uses same BIOS as XT) 5EE8-5EE9 - C&T 82c480 - EXTENDED CONFIGURATION REGISTER 3
PORTIBM PC Portable (uses same BIOS as XT) 63C0-63CF - Compaq QVision - BitBLT engine
PORTIBM PC Portable (uses same BIOS as XT) 66EC - ATI Mach64 - ???
PORTIBM PC Portable (uses same BIOS as XT) 6AEC-6AED - ATI Mach64 - ???
PORTIBM PC Portable (uses same BIOS as XT) 6AEE - ATI Mach8/Mach32 - MAXIMUM WAIT STATES
PORTIBM PC Portable (uses same BIOS as XT) 6C80-6C8F - VESA(Video Electronics Standards Association) An industry group which sets both hardware and software standards and recommendations. The term VESA is also used to denote compliance with the VESA SuperVGA BIOS Extensions, a standard set of video BIOS functions for accessing video modes of higher resolution than those defined by IBMInternational Busiuness Machines. XGA(Extended Graphics Array) Video in EISA(Enhanced Industry-Standard Architecture) A 32-bit superset of the IBMInternational Busiuness Machines ATIBM PC AT's expansion bus (which is now known as the ISA or Industry-Standard Architecture bus). slot 1
PORTIBM PC Portable (uses same BIOS as XT) 6EEC - ATI Mach64 - ???
PORTIBM PC Portable (uses same BIOS as XT) 6EEE - ATI Mach8/Mach32 - ENGINE VIDEO BUFFER OFFSET LOW
PORTIBM PC Portable (uses same BIOS as XT) 72EC - ATI Mach64 - ???
PORTIBM PC Portable (uses same BIOS as XT) 72EE - ATI Mach8/Mach32 - ENGINE VIDEO BUFFER OFFSET HIGH
PORTIBM PC Portable (uses same BIOS as XT) 72EF - ATI Mach64 - ???
PORTIBM PC Portable (uses same BIOS as XT) 76EE - ATI Mach8/Mach32 - ENGINE DISPLAY PITCH
PORTIBM PC Portable (uses same BIOS as XT) 7AEE - ATI Mach8/Mach32 - EXTENDED GRAPHICS ENGINE CONGIFURATION
PORTIBM PC Portable (uses same BIOS as XT) 7C80-7C8F - VESA(Video Electronics Standards Association) An industry group which sets both hardware and software standards and recommendations. The term VESA is also used to denote compliance with the VESA SuperVGA BIOS Extensions, a standard set of video BIOS functions for accessing video modes of higher resolution than those defined by IBMInternational Busiuness Machines. XGA(Extended Graphics Array) Video in EISA(Enhanced Industry-Standard Architecture) A 32-bit superset of the IBMInternational Busiuness Machines ATIBM PC AT's expansion bus (which is now known as the ISA or Industry-Standard Architecture bus). slot 7
PORTIBM PC Portable (uses same BIOS as XT) 7EEE - ATI Mach8/Mach32 - BOUNDS ACCUMULATOR (RIGHT)
PORTIBM PC Portable (uses same BIOS as XT) 82E8-82E9 - 8514/A and compatible - CURRENT Y POSITION
PORTIBM PC Portable (uses same BIOS as XT) 82EA-82EB - S3 Trio64 - CURRENT Y POSITION 2
PORTIBM PC Portable (uses same BIOS as XT) 83C0-83CF - Compaq QVision - Line Draw Engine
PORTIBM PC Portable (uses same BIOS as XT) 83C4 - Compaq Qvision EISA(Enhanced Industry-Standard Architecture) A 32-bit superset of the IBMInternational Busiuness Machines ATIBM PC AT's expansion bus (which is now known as the ISA or Industry-Standard Architecture bus). - Virtual Controller Select
PORTIBM PC Portable (uses same BIOS as XT) 83C6-83C9 - Compaq Qvision EISA(Enhanced Industry-Standard Architecture) A 32-bit superset of the IBMInternational Busiuness Machines ATIBM PC AT's expansion bus (which is now known as the ISA or Industry-Standard Architecture bus). - 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. color registers
PORTIBM PC Portable (uses same BIOS as XT) 86E8-86E9 - 8514/A and compatible - CURRENT X POSITION
PORTIBM PC Portable (uses same BIOS as XT) 86EA-86EB - S3 Trio64 - CURRENT X POSITION 2
PORTIBM PC Portable (uses same BIOS as XT) 8AE8-8AE9 - 8514/A and compatible - DESTINATION Y POSITION
PORTIBM PC Portable (uses same BIOS as XT) 8AEA-8AEB - S3 Trio64 - DESTINATION Y COORD 2 / AXIAL STEP CONSTANT 2
PORTIBM PC Portable (uses same BIOS as XT) 8EE8-8EE9 - 8514/A and compatible - DESTINATION X POSITION
PORTIBM PC Portable (uses same BIOS as XT) 8EEA-8EEB - S3 Trio64 - DESTINATION X COORD 2 / AXIAL STEP CONSTANT 2
PORTIBM PC Portable (uses same BIOS as XT) 8EEE - ATI Mach32 - READ EXTENDED GRAPHICS CONFIGURATION
PORTIBM PC Portable (uses same BIOS as XT) 92E8-92E9 - 8514/A and compatible - BRESENHAM ERROR TERM
PORTIBM PC Portable (uses same BIOS as XT) 92EA-92EB - S3 Trio64 - LINE ERROR TERM 2
PORTIBM PC Portable (uses same BIOS as XT) 96E8-96E9 - 8514/A and compatible - MAJOR AXIS PIXEL COUNT
PORTIBM PC Portable (uses same BIOS as XT) 96EA-96EB - S3 Trio64 - MAJOR AXIS PIXEL COUNT 2
PORTIBM PC Portable (uses same BIOS as XT) 9AE8-9AE9 - 8514/A and compatible - GRAPHICS PROCESSOR STATUS / COMMAND
PORTIBM PC Portable (uses same BIOS as XT) 9AEA-9AEB - S3 Trio64 - DRAWING COMMAND 2
PORTIBM PC Portable (uses same BIOS as XT) 9AEE - ATI Mach8/Mach32 - LINEDRAW INDEX REGISTER
PORTIBM PC Portable (uses same BIOS as XT) 9EE8-9EE9 - 8514/A and compatible - SHORT STROKE VECTORS
PORTIBM PC Portable (uses same BIOS as XT) A2E8-A2EB - 8514/A and compatible - BACKGROUND COLOR
PORTIBM PC Portable (uses same BIOS as XT) A2EE-A2EF - ATI Mach8/Mach32 - LINE DRAW OPTIONS
PORTIBM PC Portable (uses same BIOS as XT) A6E8-A6EB - 8514/A and compatible - FOREGROUND COLOR
PORTIBM PC Portable (uses same BIOS as XT) AAE8-AAEB - 8514/A and compatible - WRITE MASK
PORTIBM PC Portable (uses same BIOS as XT) AEE8-AEEB - 8514/A and compatible - READ MASK
PORTIBM PC Portable (uses same BIOS as XT) AFFF - VIDEO REGISTER
PORTIBM PC Portable (uses same BIOS as XT) B2E8-B2EB - 8514/A and compatible - COLOR COMPARE
PORTIBM PC Portable (uses same BIOS as XT) B2EE - ATI Mach32 - ???
PORTIBM PC Portable (uses same BIOS as XT) B6E8-B6E9 - 8514/A and compatible - BACKGROUND MIX
PORTIBM PC Portable (uses same BIOS as XT) B6EE - ATI Mach32 - ???
PORTIBM PC Portable (uses same BIOS as XT) BAE8-BAE9 - 8514/A and compatible - FOREGROUND MIX
PORTIBM PC Portable (uses same BIOS as XT) BAEE - ATI Mach32 - ???
PORTIBM PC Portable (uses same BIOS as XT) BEE8-BEE9 - 8514/A and compatible - MULTIFUNCTION CONTROL
PORTIBM PC Portable (uses same BIOS as XT) C2EE - ATI Mach32 - ???
PORTIBM PC Portable (uses same BIOS as XT) C6EE - ATI Mach32 - SHORT-STROKE VECTOR
PORTIBM PC Portable (uses same BIOS as XT) CAEE - ATI Mach32 - ???
PORTIBM PC Portable (uses same BIOS as XT) D2EE - ATI Mach32 - ???
PORTIBM PC Portable (uses same BIOS as XT) DAEE-DAEF - ATI Mach8/Mach32 - SCISSORS REGION (LEFT)
PORTIBM PC Portable (uses same BIOS as XT) DEEE-DEEF - ATI Mach8/Mach32 - SCISSORS REGION (TOP)
PORTIBM PC Portable (uses same BIOS as XT) E2E8-E2E9 - 8514/A and compatible - PIXEL DATA TRANSFER
PORTIBM PC Portable (uses same BIOS as XT) E2EE-E2EF - ATI Mach8/Mach32 - SCISSORS REGION (BOTTOM)
PORTIBM PC Portable (uses same BIOS as XT) E6EE-E6EF - ATI Mach8/Mach32 - SCISSORS REGION (RIGHT)
PORTIBM PC Portable (uses same BIOS as XT) EAE8-EAEB - S3 Trio64 - PATTERN
PORTIBM PC Portable (uses same BIOS as XT) FAEE - ATI Mach32 - CHIP IDENTIFICATION REGISTER
PORTIBM PC Portable (uses same BIOS as XT) FEEE-FEEF - ATI Mach8/Mach32 - DIRECT LINE DRAW REGISTER