3 ms·
Don't remember (and can't be arsed to check) if it was int21, but IBM PC BIOS does have a call to write text to the (B8000, usually) screen text buffer, complet
by a1369209993 7y ago
Don't remember (and can't be arsed to check) if it was int21, but IBM PC BIOS does have a call to write text to the (B8000, usually) screen text buffer, complete with scrolling.
- spc476 7y agoI do remember (and don't have to check [1]) but MS-DOS used interrupts 20h through 2Fh (mostly 21h). BIOS used interrupts 10h through 1Fh. 10h was for text and graphics. The "text" screen could be at either B000:0000 (physical address B0000) or B800:0000 (physical address B8000) depending on if it was monochrome or color, so to be pedantic, one had to make a few checks to see what card was installed (if you wanted to bypass the BIOS). [1] Why do I even remember this stuff? I haven't used any of this since the early 90s! Sheesh!