; ID_VL.EQU SC_INDEX = 03C4h SC_RESET = 0 SC_CLOCK = 1 SC_MAPMASK = 2 SC_CHARMAP = 3 SC_MEMMODE = 4 CRTC_INDEX = 03D4h CRTC_H_TOTAL = 0 CRTC_H_DISPEND = 1 CRTC_H_BLANK = 2 CRTC_H_ENDBLANK = 3 CRTC_H_RETRACE = 4 CRTC_H_ENDRETRACE = 5 CRTC_V_TOTAL = 6 CRTC_OVERFLOW = 7 CRTC_ROWSCAN = 8 CRTC_MAXSCANLINE = 9 CRTC_CURSORSTART = 10 CRTC_CURSOREND = 11 CRTC_STARTHIGH = 12 CRTC_STARTLOW = 13 CRTC_CURSORHIGH = 14 CRTC_CURSORLOW = 15 CRTC_V_RETRACE = 16 CRTC_V_ENDRETRACE = 17 CRTC_V_DISPEND = 18 CRTC_OFFSET = 19 CRTC_UNDERLINE = 20 CRTC_V_BLANK = 21 CRTC_V_ENDBLANK = 22 CRTC_MODE = 23 CRTC_LINECOMPARE = 24 GC_INDEX = 03CEh GC_SETRESET = 0 GC_ENABLESETRESET = 1 GC_COLORCOMPARE = 2 GC_DATAROTATE = 3 GC_READMAP = 4 GC_MODE = 5 GC_MISCELLANEOUS = 6 GC_COLORDONTCARE = 7 GC_BITMASK = 8 ATR_INDEX = 03c0h ATR_MODE = 16 ATR_OVERSCAN = 17 ATR_COLORPLANEENABLE = 18 ATR_PELPAN = 19 ATR_COLORSELECT = 20 STATUS_REGISTER_1 = 03dah