Assembly text editor
A DOS editor that writes directly to video memory.
x86 assembly, MS-DOS
Author’s notes
Amir Husain · software I wrote
It opens a file, shows it, and lets you move through it with the number keys. Written in assembly rather than C, so every part is explicit: the window, the cursor arithmetic, the keyboard handler and the special case for Enter are all instructions I wrote by hand.
There is no library between it and the screen. Characters go straight into video memory at B800:0000, with the program doing the arithmetic itself: a hundred and sixty bytes to a row, two bytes to a character cell, so the edit area starts at offset 320 and column three. Nine thousand bytes of source produce an eleven kilobyte program with no runtime underneath it.
Reading the demonstration
The recording opens a file and moves through its text. The original source handles the display, cursor positions, and key input explicitly.
About this recording and recovery
The recording and description are retained with the software. Where the recorded environment is identified, it is named beneath the recording. No additional repair history is asserted here.
Archive record
- Author
- Amir Husain
- Date
- c. 1995
- Environment
- x86 assembly, MS-DOS
- Reference
- ATX-SW-ASSEMBLY-EDITOR
The software archive preserves dates, implementation notes, and surviving source material. Contact the museum to explore the program’s documentation.