Hi all,
I was finally able to recover an assembler I wrote back in the mid 80s as a kid on my US ZX81. Being a young whipper snapper, of course I didn't document it so I've been trying to recollect how it works by reading through the code. I'm doing a video on it which I'll post here when done.
I've seen two other Assemblers so far, one by Bug Byte and one by Cinagro Software (I'm sure there are others). Both seem to load a machine code routine into memory and then you can load your assembly (similar to how MCODER does it)...which is likely preferred to my method which slaps about 8K of BASIC after the assembly (though there is a NEW command that can remove the BASIC assembler for you).
It has a few idiosyncrasies, like having to differentiate a 2-byte vs 3-byte LD instruction by affixing a + in front of it (I guess I was too lazy to figure it out in another way). It also supports labels, as well as support for relocating code with a label, i.e. START = 16544 would do that...and also lets you piece together multiple smaller bits by basically assembling code, erasing the assembly (viea ERASE) and then creating the next module...that's a way to deal with the memory limitations of having to drag around 8K of BASIC.
This is 100% written in BASIC, with the exception of two routines that are loaded from data (string of numbers) that a) increase the size of the REM via DIM and b) remove the entire BASIC or just the Assembly (NEW and ERASE). I will have to spend some time seeing what all you can do with it. I think it supports most Z80 instructions, and the ones it doesn't, you can enter via the DATA statement. Once debugged, then I need to think about writing a guide for it (or maybe the video I create will be that) before distributing it to the general public.
Here are some screenshots, with the first two showing what it looks like after running the program with the associates assembly:
- Loop.png (82.44 KiB) Viewed 214 times
- Graphic.png (80.49 KiB) Viewed 214 times
- Instr_1.png (89.58 KiB) Viewed 214 times
- Instr_2.png (92.23 KiB) Viewed 214 times