;**************************************************************************** ;* ;* The Universal VESA VBE ;* ;* Copyright (C) 1993 Kendall Bennett. ;* All rights reserved. ;* ;* Filename: $RCSfile: _video7.asm $ ;* Version: $Revision: 1.2 $ ;* ;* Language: 8086 Assembler ;* Environment: IBM PC (MS DOS) ;* ;* Description: Assembly language support routines for Video 7 SuperVGA's. ;* ;* Contains code to perform initialisation, bank switching ;* and extended page flipping if possible. ;* ;* $Id: _video7.asm 1.2 1993/09/24 05:23:45 kjb release $ ;* ;* Revision History: ;* ----------------- ;* ;* $Log: _video7.asm $ ;* Revision 1.2 1993/09/24 05:23:45 kjb ;* Fixed a number of bugs. ;* ;* Revision 1.1 1993/09/19 01:27:05 kjb ;* Initial revision ;* ;**************************************************************************** grVIDEO7_V1 = 0 ; Video 7 version 1-4 chipsets grVIDEO7_V5 = 1 ; Video 7 version 5 chipsets ;---------------------------------------------------------------------------- ; VIDEO7V1_bank Change to a new 64k bank (reading and writing) ;---------------------------------------------------------------------------- ; ; Entry: AX - Number of 64k bank ; ; Registers: All preserved! ; ;---------------------------------------------------------------------------- PROC VIDEO7V1_bank far push ax push cx push dx and al,0Fh ; Mask to 4 bits mov ch,al mov dx,3C4h mov ah,ch and ah,1 mov al,0F9h ; Index of Extended Page Select register out dx,ax ; Program PS bit in register mov al,ch and al,1100b ; Bits 3-2 for read field mov ah,al shr ah,2 ; Bits 1-0 for write field or ah,al ; Combine two values mov al,0F6h out dx,al ; Index the bank select register inc dl in al,dx ; Read old value and al,11110000b ; Zero out old bits or al,ah ; Combine with new values out dx,al ; Program the values mov ah,ch and ah,10b ; Mask out bit 2 shl ah,4 ; Put into bit 5 mov dx,3CCh ; Address Miscellaneous register in al,dx ; Read old value and al,0DFh ; Zero bit 5 mov dx,3C2h or al,ah ; Or in the page bit out dx,al ; Program the new value pop dx pop cx pop ax ret ENDP VIDEO7V1_bank VIDEO7V1_bank_len = ($-VIDEO7V1_bank) ;---------------------------------------------------------------------------- ; VIDEO7V5_bank Change to a new 64k bank (reading and writing) ;---------------------------------------------------------------------------- ; ; Entry: AX - Number of 64k bank ; ; Registers: All preserved! ; ;---------------------------------------------------------------------------- PROC VIDEO7V5_bank far push ax push dx and al,0Fh ; Mask to 4 bits shl al,4 ; Shift into bits 7-4 mov ah,al mov dx,3C4h mov al,0E8h ; Index of write bank register out dx,ax ; Program the write bank mov al,0E9h ; Index of read bank register out dx,ax ; Program the read bank pop dx pop ax ret ENDP VIDEO7V5_bank VIDEO7V5_bank_len = ($-VIDEO7V5_bank) ;---------------------------------------------------------------------------- ; VIDEO7V5_rbank Change to a new 64k read bank (reading only) ;---------------------------------------------------------------------------- ; ; Entry: AX - Number of 64k bank ; ; Registers: All preserved! ; ;---------------------------------------------------------------------------- PROC VIDEO7V5_rbank far push ax push dx and al,0Fh ; Mask to 4 bits shl al,4 ; Shift into bits 7-4 mov ah,al mov dx,3C4h mov al,0E9h ; Index of read bank register out dx,al ; Program the value pop dx pop ax ret ENDP VIDEO7V5_rbank VIDEO7V5_rbank_len = ($-VIDEO7V5_rbank) ;---------------------------------------------------------------------------- ; VIDEO7_page Set the extended CRT starting address. ;---------------------------------------------------------------------------- ; ; Entry: BL - Index of start address low register ; BH - Bits 7-0 of new start address ; CL - Index of start address high register ; CH - Bits 15-8 of new start address ; SI - Bits 16+ for new start address ; ; Registers: AX,BX,CX,DX,SI ; ;---------------------------------------------------------------------------- PROC VIDEO7_page far SetLowStartAddress mov dx,3C4h mov al,0F6h out dx,al ; Index extended start address inc dx in al,dx ; Read current value and al,0CFh ; Zero out start address 17-16 bit 5-4 and bl,3 ; Mask out all but bottom 2 bits shl bl,4 ; Shift left into correct position or al,bl ; Or in the new start address out dx,al ; Output the address ret ENDP VIDEO7_page VIDEO7_page_len = ($-VIDEO7_page) ;---------------------------------------------------------------------------- ; VIDEO7V1_setup Setup the SuperVGA for correct operation ;---------------------------------------------------------------------------- PROC VIDEO7V1_setup near outp 3C4h, 6, 0EAh ; Enable extended registers ret ENDP VIDEO7V1_setup VIDEO7V1_setup_len = ($-VIDEO7V1_setup) ;---------------------------------------------------------------------------- ; VIDEO7V5_setup Setup the SuperVGA for correct operation ;---------------------------------------------------------------------------- PROC VIDEO7V5_setup near outp 3C4h, 6, 0EAh ; Enable extended registers modinx 3C4h, 0E0h, 80h, 80h; Set split bank mode ret ENDP VIDEO7V5_setup VIDEO7V5_setup_len = ($-VIDEO7V5_setup) ;---------------------------------------------------------------------------- ; VIDEO7_exit Return the SuperVGA to default operation ;---------------------------------------------------------------------------- PROC VIDEO7_exit near outp 3C4h, 6, 0AEh ; Disable extended registers modinx 3C4h, 0E0h, 80h, 0 ; Disable split bank mode ret ENDP VIDEO7_exit VIDEO7_exit_len = ($-VIDEO7_exit) ;---------------------------------------------------------------------------- ; VIDEO7_init ;---------------------------------------------------------------------------- ; We have a Video7 V7VGA SuperVGA, so set up vectors for this card. ;---------------------------------------------------------------------------- PROC VIDEO7_init ; Setup the correct vectors to use the Video7 bank switching and paging ; routines. The version 5 chipsets support the dual banking mode. mov [TwoBanks],false mov [WriteBank16],offset VIDEO7V1_bank mov [WriteBank16Len],VIDEO7V1_bank_len mov [WriteBank256],offset VIDEO7V1_bank mov [WriteBank256Len],VIDEO7V1_bank_len mov [NewPage16],offset VIDEO7_page mov [NewPage16Len],VIDEO7_page_len mov [NewPage256],offset VIDEO7_page mov [NewPage256Len],VIDEO7_page_len mov [SetupSVGA],offset VIDEO7V1_setup mov [SetupSVGALen],VIDEO7V1_setup_len mov [ExitSVGA],offset VIDEO7_exit mov [ExitSVGALen],VIDEO7_exit_len cmp [CntChipID],grVIDEO7_V5 jl @@Exit mov [TwoBanks],true mov [WriteBank16],offset VIDEO7V5_bank mov [WriteBank16Len],VIDEO7V5_bank_len mov [WriteBank256],offset VIDEO7V5_bank mov [WriteBank256Len],VIDEO7V5_bank_len mov [ReadBank16],offset VIDEO7V5_rbank mov [ReadBank16Len],VIDEO7V5_rbank_len mov [ReadBank256],offset VIDEO7V5_rbank mov [ReadBank256Len],VIDEO7V5_rbank_len mov [SetupSVGA],offset VIDEO7V5_setup mov [SetupSVGALen],VIDEO7V5_setup_len @@Exit: ret ENDP VIDEO7_init