i cheated the program
the call to INT 10h, 4F11h returns 4F11h
so, i set a breakpoint and forced AX = 4Fh
this is the debug version of the program...
1073:0017 CD21 INT 21
1073:0019 B8114F MOV AX,4F11
1073:001C 33DB XOR BX,BX
1073:001E BF0000 MOV DI,0000
1073:0021 CD10 INT 10
1073:0023 E8F508 CALL 091B
-bp0 23
-g
VESA BIOS Extension/Flat Panel Interface (VBE/FP) Function Test Program.
Paused, hit a key.
AX returned from function request = AX=4F11 BX=0000 CX=1A9F DX=0197 SP=0200
BP=0000 SI=0000 DI=0000
DS=0F88 ES=0F88 SS=0F68 CS=1073 IP=0023 NV UP EI PL ZR NA PE NC
1073:0023 E8F508 CALL 091B ;BR0
-rax 4f
-g
004F
VESA BIOS Extension/Flat Panel Interface Function 0 is supported.
AH = 00: Function call successful.
Supplemental VBE Signature =
Supplemental VBE Version
Major version, Minor version = 00, 00
Bitfield of supported subfunctions
7 6 5 4 3 2 1 0
0 0 0 0 0 0 0 0
OEM Software Revision
Major version, Minor version = 00, 00
Pointer to Vendor Name String = 0000:0000
Pointer to Product Name String = 0000:0000
Pointer to Product Revision String = 0000:0000
Pointer to OEM String = 0000:0000
End function 0 display. Paused, hit a key.
AX returned from function request = 4F11
VESA BIOS Extension/Flat Panel Interface Function 0 is not supported.
Program terminated normally (1)
-q