6502.org

I'm getting ready to release an update. I'll try to fix these issues before it goes out. it shows how much I was rushing to get the documentation up to date. I hate doing documentation, even though I appreciate it when its done.

thanks!

Daryl

The updates have been completed.

Several documentation errors were corrected in context selective help and help file.
Corrected COP opcode to require an Immediate operand. It was treated like BRK, with an optional operand.
Corrected assembly listing with values greater than $FFFF being truncated.
Added optional parameters to .DATE and .TIME directives. These allow changing or omitting the separator characters.

Added .LSTR & .LSTRING directives. These work just like .STR & .STRING but have a 16 bit length variable vs. an 8 bit length. Maximum editor line length of 1024 limits the strings to about 1016 characters, but that's better than 255 for longer strings. There are work arounds for even longer strings.

The new version is 1.3.4 and the Executable and source code are on my website.
Here's the link -> https://sbc.rictor.org/kowalski.html

Enjoy!

Daryl

OK, I'll look into this. I'm swamped with other stuff for a while, but will work on this as time permits.

Thanks!

Daryl

The P comes from "Processor status." When I see SR, my mind goes to "Shift Register," because of the VIA. I never had any trouble with S, because the 6502 had TXS and TSX right from the beginning, eight years before the '816 was out. The one that does trip me up though is K, and I keep having to look it up because I can't remember if it's "data banK" or "program banK." I do like the fact that all the assembly-language mnemonics are three letters though.

All the machine language monitors I've used over the last 40+ years, starting with Jim Butterfield's Supermon, through Supermon 64, Commodore's resident monitor in the C-128 (basically Supermon 64 with some enhancements to take advantage of the 128) and Fiscal Information's LKMON (which shipped with the Lt. Kernal hard drive subsystem) use two-character names for registers. Jim Butterfield used AR, XR and YR for the accumulator and index registers, and the same register designations I mentioned for the program counter, status register and stack pointer. When I wrote Supermon 816, I copied the register naming pattern established long ago by Jim Butterfield because I knew that pattern would be familiar to a lot of potential users.

As for the TSX and TXS instructions (and the 816's TCS and TSC instructions), those names are the way they are because MOS Technology followed the IEEE-694 standardized assembly language mnemonic structure (now inactive)—register naming had little to do with it. That standard specified three character mnemonics, with the first character indicating the nature of the operation (e.g., L for load, T for transfer, S for store, etc.). With only three characters allowed in the mnemonic, it took some creativity to somehow represent the operation, the source and the destination. That is why register-to-register mnemonics use a single letter for each register.

So, I tested this on all 4 versions I have on my website. All 4 assemble with LDA #0 vs. LDA #123. This includes the last version Michal posted.

Do you have a version where this works? it would be easier to troubleshoot if I had a working version to reference.

Daryl

I got the same listing as you on all 4 versions.

if I read it correctly, we should see LDA #123 vs LDA #0. So there is a problem, even though there are no ERROR messages generated.

So I was wanting to know what version this worked on previously?

I scraped up a copy of 1.2.6 and the conditional assembly worked on that. As I recall, Michal had done some work with a third level of variables that was present in the 1.2.12 version he posted to github. I have the source for 1.2.6 so I'll compare that to see if I can find the issue.

DAryl

So its even more odd now. I got home and ran the code and experienced the problem. Now, without changing anything, its working correctly on 3 versions.

This is going to be a hard one to track down.

Daryl