Original author(s) Size 8KB | Platform Atari 400/800/XL/XE Type Assembler | |
Developer(s) Shepardson Microsystems Stable release 1.0 / 1981; 36 years ago (1981) | ||
The Atari Assembler Editor is a cartridge-based development system used to edit, assemble, and debug 6502 programs for the Atari 8-bit computers. It was programmed by Kathleen O'Brien of Shepardson Microsystems. It was the first commercially available assembler for the Atari 8-bit computers.
Contents
In the manual, Atari recommends the Assembler Editor as a tool for writing subroutines to speed up BASIC, primarily because assembly times are extremely slow for anything but the smallest programs. The Atari Macro Assembler was offered by Atari to provide better performance and more powerful features, such as macros, but it was disk-based, copy-protected, and did not include an editor or debugger.
Despite the recommendation, commercial software was written using the Assembler Editor, such as the game Galahad and the Holy Grail.
Details
The Assembler Editor is two-pass 6502 assembler in an 8KB cartridge. Both source and object code can be in memory simultaneously, allowing repeated editing, assembly, and running of the resulting code without accessing a disk or tape drive.
Edit
The cartridge starts in EDIT mode. The programmer enters lines of assembly source into the Atari BASIC-like editor. Source text must be prefixed with a line number, or it is interpreted as a command. Errors are reported with numeric error codes.
Code is assembled with the ASM command.
Debug
The debugger, really a monitor, is entered with the BUG command. The debugger allows the viewing and changing of registers and memory locations, code tracing, single-step and disassembly.
The X command returns to EDIT mode.
Example Code
The following is example code for Hello World! written in Atari assembly language:
Legacy
Optimized Systems Software purchased the original rights to the Atari Assembler Editor from Shepardson Microsystems and released an improved version as EASMD, which was superseded by MAC/65 in 1982. The Assembler Editor continued to be available from Atari and increased in popularity as the price dropped to US$10 or $5 in the latter half of the 1980s.