I'm trying to read the value 1000h which can be found in the address 0000h:044Ch and put it in the ax register by using the mov instruction. Every time I get back another value than the expected 1000h.
This is the instruction I use in TASM:
mov ax, [word ptr 0000h:044Ch]
I have checked the vaue in ax in the debugger.
You will have to set one of the segment registers to 0x0000 and then access the word at offset 044ch through that segment register. Something like this should work:
xor ax, ax ; XOR register with itself same as setting register to 0
mov es, ax ; ES = 0
mov ax, [es:044ch] ; Get size of text video page of current display mode in bytes
; AX now has the 16-bit WORD value at 0000h:044ch
shr ax, 4 ; Divide by 16 to get size in paragraphs
add ax, 0b800h ; Add to the base of text video memory segment to get page 1 segment
; Then you can put AX in a segment like ES to access text video memory
mov es, ax ; ES = segment of page 1 of current text video mode