MEM 0040h:0089h U - VIDEO (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./VGAVideo Graphics Array(Video Graphics Array) The video adapter introduced with the IBMInternational Busiuness Machines PS/2IBM PS/2, any model series of computers.) - MODE-SET OPTION CONTROL Size: BYTE SeeAlso: MEM 0040h:0087h,MEM 0040h:0088h Bitfields for Video mode-set option control: Bit(s) Description (Table M0027) 7,4 requested scan lines 0 0 350-line mode requested 0 1 400-line mode at next mode set 1 0 200-line mode requested 1 1 reserved Note: Apparently VGAVideo Graphics Array(Video Graphics Array) The video adapter introduced with the IBMInternational Busiuness Machines PS/2IBM PS/2, any model series of computers. BIOS(Basic Input/Output System) A set of standardized calls giving low-level access to the hardware. The BIOS is the lowest software layer above the actual hardware and serves to insulate programs (and operating systems) which use it from the details of accessing the hardware directly. mode set disregards bit 7 and uses byte 40h:88h to determine 200/350 selection when bit 4 is zero. Presumably bit 7 is a convenience for other purposes. Bit 7 is reset to zero after the mode set. 6 display switching enabled 5 reserved 4 if set: use 400-line mode at next mode set if clear: [VGAVideo Graphics Array(Video Graphics Array) The video adapter introduced with the IBMInternational Busiuness Machines PS/2IBM PS/2, any model series of computers.] emulate 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. at next mode set [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.] emulate 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., digital monitor, 200 lines, 8x8 text Note: this bit is set by the video mode set on VGAVideo Graphics Array(Video Graphics Array) The video adapter introduced with the IBMInternational Busiuness Machines PS/2IBM PS/2, any model series of computers., unchanged on 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. 3 default palette loading DISabled at mode set 2 mono display 1 gray scale summing enabled 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.] =1 if VGAVideo Graphics Array(Video Graphics Array) The video adapter introduced with the IBMInternational Busiuness Machines PS/2IBM PS/2, any model series of computers. active, =0 if 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.] reserved, zero Note: the Tseng ET4000 BIOS(Basic Input/Output System) A set of standardized calls giving low-level access to the hardware. The BIOS is the lowest software layer above the actual hardware and serves to insulate programs (and operating systems) which use it from the details of accessing the hardware directly. v3.00 uses bits 6-4 of 88h and bits 6-5 of 89h to specify graphics-mode refresh rates as follows 88h/6 640x480: 1 for 72Hz,0 for 60Hz 88h/5+89h/6 800x600: 00 60Hz 01 56Hz 11 72Hz 88h/4+89h/5 1024x768: 00 interlaced 01 60Hz 10 72Hz??? 11 70Hz