May 26, 2022 · The BIOS assigned INT 08H+ for their own interrupt handlers, for instance int 10H for VGA MODE switch, or int 13H for hard drive services. (Table of software-interrupt …

Sep 17, 2023 · The point is, if your switches is set to MDA, it gets stored into Equipment Flag bits, and when setting a new mode with Int 10h, the Equipment Flags are checked for display type. …

Jun 28, 2017 · On the way to protected or long modes, real mode code needs to provide a lot of visual feedback. Video services INT 10H provide this functionality, but lack fluidity. This …

Jan 4, 2019 · Your code is correct; a yellow prompt means that you’re using the red/green/brown palette. However, to get the low intensity variant, you also need to call interrupt 10h service …

May 26, 2019 · INT 10h/AH=06h and INT 10h/AH=07h can be used either to scroll a rectangular region of the screen or to clear the screen to a specified foreground/background colour …

mov si, HelloString lodsw mov cx,ax mov ah,0eh .repeat: lodsb int 10h loop .repeat ; .done: ret Beware that the above may not be the fastest way to loop, anymore. I once read that the more …

Aug 4, 2021 · How does the BIOS distinguish Interrupt(08h-12h) from INT instructions, vs. actual exceptions inside the CPU? 25 How can a 32-bit x86 CPU start with reset vector 0xFFFFFFF0 …

Oct 12, 2020 · Since the original IBM PC only supported 8 hardware interrupts, this meant that vectors 8 through 15 were used for hardware interrupts. IBM then started assigning BIOS …

Feb 25, 2017 · bits 16 mov dl, 0 ; Cursor position column mov dh, 0 ; Cursor position row ; Draw a really simple UI ; Draws a blue background mov ah, 09h mov al, 32 mov bl, 10h mov cx, …

pop dx rol dx, 1 push dx and dx, 0000000000000001 add dx, 30h push cx mov al, dl int 10h pop cx When you know that the BIOS.Teletype function expects the character in the AL register, …