GENOA SuperVGA Chips. Genoa 5100/5200 Tseng ET3000 chips 256 Kbytes 5300/5400 Tseng ET3000 chips 512 Kbytes 6100 Own chip 256 Kbytes ?? 6200/6300 Own chip 256 Kbytes max 800x600/16 or 640x400/256 6400/6600 Own chip 512 Kbytes max 1024x768/16 or 800x600/256 6600 is the 6400 for MicroChannel 64/6600A support 70Hz refresh rate. 7900 is Tseng ET4000 based with SS24 DAC. New 7000 series appears to be Tseng 4000 based. 3C3h (R/W): Global Enable PS/2 Register bit 0 VGA Microchannel enabled if set 3C4h index 5 (R/W): Configuration Register bit 0 (R) PC/AT if set, PS/2 else 1 (R) 8bit bus if set, 16bit else 2 (R) 8bit ROM if set, 16bit else 3 Reserved 4 (R) I/O address 3xx if set, 2xx else 5-6 ROM BIOS size: 0: 24kb ROM 1: 30kb ROM 2: 32kb ROM 3: 0kb ROM 7 8 simultaneous fonts if set, 2 else 3C4h index 6 (R/W): Memory Segment Register bit 0-2 Read bank no. 3-5 Write bank no. 6 If clear use 3C2h bit 5 as A16 rather than bit 0/3 of this register. 3C4h index 7 (R/W): Enhanced Control #2 bit 0 External Clock select bit 2. Bits 0-1 are in 3C2h/3CCh bits 2-3. 1 Allow frequencies above 50MHz 2 16 bit video memory access if set 3 VGA on Motherboard if set, Card else 4 Reserved 5 TTL monitor if set, Analog else 6 Non-Maskable Interrupts Enabled if set 7 Reserved 3C4h index 8 (R/W): Enhanced Control #3 bit 0 MDA,Hercules or CGA emulation if set 1 MonoChrome Autoswitch if set. Causes NMI if 3B8h is written to 2 Color Autoswitch if set. Causes NMI if 3D8h is written to 3 EGA operation if set, VGA else 4 60Hz Vertical if set, 70Hz else 5 Enable flicker free function 6 Enable extended memory addressing 7 Enable 1024x768 addressing 3C4h index 10h (R/W): Enhanced Control #4 bit 0 Fast Scroll if set 1 Fast Decode if set 2 Enables 2 bank access if set 3 Pre_Wait enabled if set 4-5 Reserved 6 Fast Write enabled if set 7 Select memory bank 0 or 1 3CEh index 9 (R/W): Enhanced Control #5 bit 6 If set Access even pixels in plane 0/1 and odd pixels in plane 2/3. (Mode 7Fh) 7 If set Display even pixels from plane 0/1 and odd pixels from plane 2/3. (Mode 7Fh) 3CEh index 0Ah (R/W): Program Status Register 1 bit 0-7 Scratch 3CEh index 0Bh (R/W): Program Status Register 2 bit 0-7 Scratch 3d4h index 2Eh (R/W): Herchi Register bit 0 If set Maximum Scan Line Register (3d4h index 9) is programmable in CGA modes 1 Enables Chinese applications in Hercules mode if set 2-7 Reserved 3d4h index 2Fh (R/W): Interlace Control Register bit 0 Interlace active if set 1 Enable Quadword addressing mode 2 Select Character Clock as memory addressing counter clock 3 Interlaced Graphics/Alpha mode 4-7 Reserved 46E8h (R): Global Enable PC/AT Register bit 3 Adapter VGA enabled if set Bank select: Separate read and write banks are selected through 3C4 index 6. Memory locations: $C000:$37 2 bytes start of info table from start of ROM Usually $C000:$B4 $C000:x 1 byte $77 $C000:x+1 1 byte Version. $00 Genoa 6200 or 6300 $11 Genoa 6400 or 6600 $22 Genoa 6100 $33 Genoa 5100 or 5200 (Tseng 3000) $55 Genoa 5300 or 5400 (Tseng 3000) $C000:x+2 2 bytes $6699 ID Genoa Chip Set: ad:=memw[$C000:$37]; if (mem[$C000:ad]=$77) and (memw[$C000:ad+2]=$6699) then case mem[$C000:ad+1] of $33,$55:TSENG 3000 chips with special modes; $22:GENOA_6100 0:GENOA_6200 or GENOA_6300 $11:GENOA_6400 or GENOA_6600 end; Note that this would also ID the UMC 85c408 as a GENOA 6400, so test for UMC first Video Modes: The Genoa 5xxx series boards use Tseng modes. The 6xxx series boards use the following modes: 40h T 80 25 2 SuperEGA BIOS 3.0+ 41h G 720 348 2 SuperEGA BIOS 3.0+ at B000h 42h G 720 348 2 SuperEGA BIOS 3.0+ at B800h 43h T 80 29 2 (9x12) 44h T 80 32 2 (9x11) 45h T 80 44 2 (9x8) 46h T 132 25 2 (8/9x14) 47h T 132 29 2 (8/9x12) 48h T 132 32 2 (8/9x11) 49h T 132 44 2 (8/9x8) 58h T 80 32 16 (9x16) 59h G 720 512 16 PL4 5Ah T 100 42? 16 5Bh G 640 350 256 P8 5Ch G 640 480 256 P8 5Dh G 720 512 256 P8 5Eh G 800 600 256 P8 5Fh G 1024 768 16 PL4 60h T 132 25 16 (8x14) 61h T 132 29 16 (8x8) 62h T 132 32 16 (8x11) 63h T 132 44 16 (8x8) 64h T 132 60 16 (8x8) 6Ah G 800 600 16 PL4 6Bh T 100 75 16 6Ch G 800 600 256 P8 72h T 80 60 16 73h G 640 480 16 Pl4 74h T 80 66 16 (8x8) 75h G 640 528 16 PL4 SuperEGA BIOS 3.0+ 76h T 94 29 (8x14) SuperEGA BIOS 3.0+ 77h G 752 410 16 PL4 SuperEGA BIOS 3.0+ 78h T 100 75 16 79h G 800 600 16 PL4 7Ah T 114 60 (8x8) SuperEGA BIOS 3.0+ 7Bh G 912 480 16 PL4 SuperEGA BIOS 3.0+ 7Ch G 512 512 16 PL4 7Dh G 512 512 256 P8 7Eh G 640 400 256 P8 7Fh G 1024 768 4 PL2 Mode 7Fh: 1024x768 4 color 2 bits per pixel planar mode Even pixels are in planes 0 and 1, odd pixels are in planes 2 and 3. BIOS Extensions: ----------1010F0----------------------- INT 10 - Genoa 7900 Set 24bit mode AX = 10F0h BL = 3Eh Sets 640 x 480 16M color mode. Return: AX = 0010h if successful ----------1010F0----------------------- INT 10 - Genoa 7900 - Get DAC Type AX = 10F1h Return: AX = 0010h BX = 0000h Normal VGA DAC 16/256 colors = 0001h HiColor 5/5/5 format 16/256/32K colors = 0002h HiColor 5/6/5 format 16/256/32K/64K colors = 0602h Special New DAC 16/256/32K/64K/256K colors = 0802h Special New DAC 16/256/32K/64K/16M colors Note: *Genoa's MultimediaVGA Model 7900 will return BX = 0802H (8/8/8 format capability) and Model 7900sx will return BX = 0602H (6/6/6 format capability). Note: The one Genoa 7900 I've seen returns BX = 0803h.