yes, exactly - it can make a big performance difference in Taliforth. Have some words that 'inline' access to a few key zeropage registers would avoid a bunch of (even inline) stack manipulation in tight loops.

Conversely, a bunch of non-performance-critical Tali words are effectively inlining ...

I wanted to streamline some code like u A ! and A @ for heavily used variables, so I started hand-coding assembly for some inline "register" words that interacted directly with fixed 16-bit zero page cells.

In Taliforth (and I guess many other 6502 forths) we use X as the data stack pointer so ...

yes, i like Garth's idea of adding a couple of primitives too. I think I can speed up the 65c02-on-65c02 emulator a lot with inlined const and some well-chosen bit-twiddling words for all the flag updates. needs a bit of thought about exactly what words tho.

yes, for Tali. Looks like it automatically does the inlining from the postpone literal already :heart:


42 const fubar ok
fubar . 42 ok
.s <0> ok
: snafu fubar + ; ok
see snafu
...
943 2A lda.#
945 dex
946 dex
947 0 sta.zx
949 1 stz.zx
94B 80BE jsr 2 STACK DEPTH CHECK
94E clc
94F 0 lda.zx
951 2 ...

It seems like CONSTANT words compile a reference to themselves, so the value isn't looked up til run-time.
I guess this allows the value to change before the word executes which is perhaps a benefit in some cases.

I want to make a CONST word which just inlines itself at compile-time, so the value ...

Confirmed that Klaus Dormann's test suite passes with the code as shown above:

- the 6502 functional tests take about 45m to complete at 100MHz. These tests run natively in about 97M cycles. The emulated version takes 264B(!) cycles, an average of 2700 native cycles per emulated cycle, although ...

That's a good idea to use DISASM! I updated the listing above to fix BCD mode and also added a P. word to show status flags which was invaluable while fighting with BCD - what a mess that is. The randomized tests all pass now, still working thru checking Klaus suite tho it is super slow

Not yet, just the randomized tests for all wdc opcodes I linked above. That's a good thought tho, might need to implement decimal mode and take a stab at it.

Emulate the 65C02 in a 65C02 forth, itself running on a 65C02 emulator of course... To illustrate it emulates the assembled version of its own UM* word, as well as passing a large suite of tests.

For some reverse-engineering I wanted some simple logic equations describing each opcode to reason ...

in case it's useful I wrote a simple python implementation of prodos8 which makes it easy to create and manage prodos images anywhere python runs.

see https://github.com/patricksurry/pyprodos

i've found this supports a painless build cycle for either simulated or hardware 6502 stuff, especially ...

lol, the keyboard is this nullbits kit, love it!

https://nullbits.co/nibble/

it does in fact *also* have some underglow LEDs which I use to indicate different layers.

it has a more powerful CPU than the breadboard, but i just use it to send ascii keypresses using SPI

Here's the result of my latest Forth adventure (see what I did there?). This is a full TaliForth port of the original Colossal Cave Adventure (350pt version) for the 65C02 that runs in just 64K. Thanks to SamCoVT for all the support hacking on the amazing TaliForth code base!

source on github

I ...

I ended up implementing >SREC / SREC> words for my taliforth console which makes it easy to paste compiled code snippets thru the terminal.

just for fun i'm also trying a very simple delta-coding thing so I can generate small binary patches with respect to the code that's already in the eeprom ...

For simplicity I added the generated .asm code to the repo as well as updating the author info. Happy holidays all.

Great sleuthing - that is indeed him, and he is happy to share for educational use:

.. Yes, I wrote the 2KSA when I was *supposed* to be writing my PhD thesis on nitrogen fixation in soybeans. Forty-some years later, I'm still using microcomputers (Raspberry Picos running Python) to study nitrogen ...