edas v1.8 ( C128 6502 assembler )
Version V1.8
By Mike Webb ( circa 1988 ) Recovered, archived and documented by Kevin Edwards
This is Mike Webb's 6502 Editor/ Assembler for the C128 - a very early IDE. Software Creations used this for their early NES development. It was also used for Commodore 64/128 games and utilities. Several other development studios around the Manchester area also used it, most likely without permission! Previous to this there was a version for the Einstein computer which was also developed by Mike Webb, known as ED.COM. Later versions of the editor/assembler were made for PC. These were written by Ste Ruddy and Mike Webb. Other platforms and processors were supported by these later versions - SNES, Z80, GAMEBOY etc.
I used this during the early development of NES Magic Johnson's Fast Break.
Source files are stored in tokenised format and have the extension '.src'. ASCII characters 0x80-0xff have special meanings and are expanded into several characters for mnemonic names and assembler commands.
The editor/assembler is contained within a single tokenised source file ( edasv1.8.src ) and can only be build using itself - the .prg is included here too to do this.
I have also included a de-tokenised version of the source file ( edasv1.8.asm ) so you can browse this using your text editor of choice.
I hope it is useful to people who have an interest in 6502 assembly language programming and to those who wish to know how games were made in the 1980s.
Build Steps
To build the code you will need to use the pre-assembled editor/assembler to assemble itself!
You will need to create an emulator disk image with 'a1.8.prg' and 'edasv1.8.src' ( such as edas.d71 ) and mount it to an emulator drive.
Run 'a1.8.prg' on a C128 / emulator with:-
BLOAD"A1.8" SYS 7168
Load up the tokenised source file 'edasv1.8.src' - see instructions below.
Additional Notes
There are no proper instructions available at this moment in time. I hope to add these in the near future.
There is basically a command mode, editor mode and debug mode.
On start-up you are in command mode:-
- Shift + Home Enter Command Mode from editor
- $ Perform a Directory listing
- L"edasv1.8.src" Load source file into memory
Enter 'X' to exit command mode and go into Editor mode.
You can find me on Twitter @KevEdwardsRetro where I ramble on about all kinds of retro computer and video game things. Please drop by and say hello.
Thank you for reading this far.