MX 86000 512K, 800x600x256c/1024x768x16c MX 86010 1MB, 1024x768x256colors Support chips: MX8602 Clock chip. Supplies 25.175, 28.322, 40,44.9, 14.3, 16.3, 36, 65 MHz 3C4h index 26h (R/W): bit 0 Set for MX86000, clear for MX86010 3C4h index 30h-33h (R/W): Scratch Note: used by MXIC utilities to store the old IRQ 2 interrupt address. 3C4h index 34h (R/W): bit 0-1 Monitor type: 0=VGA, 1=8514A, 2=NEC 3D, 3=NEC 4D 3C4h index 65h (R/W): bit 6 Set to enable access to extended registers (3C4h index 8-FFh). 3C4h index 90h (R/W): bit 0-1 ?? 3C4h index A7h (W?): Enable extensions bit 0-7 Writing 87h to this register enables the MXIC extensions, writing 0 disables them. 3C4h index C2h (R/W): bit 2-3 Video RAM installed: 0=256k, 1=512k, 2=1M 3C4h index C3h (R/W): bit 2 Set to enable banked access via index C5h. 3 If set doubles image horizontally 7 Bus width?. 0=8 bit, 1=16 bit. 3C4h index C4h (R/W): bit 0 Clock Select bit 2 (bits 0-1 are in 3C2h/3CCh bits 2-3) 3 Select Memory Clock for Video Clock ? 6,7 Disables display if set 3C4h index C5h (R/W): Bank register bit 0-3 Write bank in 64k blocks. 4-7 Read bank in 64k blocks 3C4h index F0h (R/W): bit 0-1 3 if interlaced, 0 if not. 3 If clear the display will wrap at 256K. 4 If set display width or scanline width is slightly wrong ? 7 Disables display if set 3C4h index F1h (R/W): bit 0-1 Display Start Address bit 16-17 3C4h index F2h (R/W): bit 7 Set if IRQ2 enabled, clear if not. 3C4h index F3h (R/W): bit 0 Scrambles display if set ? 1 Vertical overflow ? 2 Disables display if set 3 If set the same (random ?) line is repeated down the entire screen 5 Disables display if set 6 If set the same (random ?) line is repeated down the entire screen 7 If set image looses vertical sync ?? Apparently the sequencer (3C4/5h) does not decode bit 3-4 of the index, thus index 7 is duplicated at 0Fh, 17h and 1Fh. Test for MXIC chip: old:=rdinx($3C4,$A7); wrinx($3C4,$A7,0); {Disable extensions} if not testinx($3C4,$C5) then begin wrinx($3C4,$A7,$87); if testinx($3C4,$C5) then if (rdinx($3C4,$26) and 1)=0 then MXIC MX86010 else MXIC MX86000 end; wrinx($3C4,$A7,old); Video modes: 50h T 132 25 16 (8x16) 51h T 132 30 16 (8x16) 55h G 800 600 16 PL4 56h G 1024 768 16 PL4 57h G 640 350 256 P8 58h G 640 400 256 P8 59h G 640 480 256 P8 5Ah G 800 600 256 P8 5Bh G 1024 768 256 P8