The Single-Board 6502
Assembler/text Editor (sold by M.S.S. Inc., POB 2034, Marshall, TX 75670).
What can you get for $25.00 these days? Well, if you like to tinker with software, you could get the beginnings of an interesting little assembler/editor. Or, you could get an education in what makes an assembler tick.
Actually, you do get more than just the beginnings of an assembler. It's almost complete.
What's all this nonsense you ask? OK, I'll try to describe it.
For $25.00 you get a standard, no frills line editor and 2-pass assembler that resides in slightly over 2K of memory. The assembler mnemonics are close to MOS Technology's standard. How close? The actual mnemonics correspond perfectly. It's the operand formats that differ. I'm sure you could get used to it, though.
The best thing about the package is that you get a source listing for it included for no extra money. It's not very well commented, but it's better than nothing. A serious student of the 6502 dialect should have little problem figuring out what's going on.
The reason I said that the package is ALMOST complete is because there's no built-in means of saving or loading assembler source code to/from cassette (or other mass storage device). If you want to do that, you'll have to add it yourself. They do, however present an example of a routine to add a new command to the system so, if you know what you're doing, you could probably add the necessary cassette support routines.
The fact that the source listing is included opens a rather exciting possibility. It's possible to make the assembler into a cross-assembler for some other CPU – like the 1802, for example. Then you could get that 1802 Simulator program by Dann McCreary and have a complete 1802 development system on your 6502!!!
Does that turn you on?
This assembler and its associated documentation is NOT for beginners! But, could be a good value if you know what you're getting into.