Forth Advanced Run-Time
I've been coding in assembly on a Forth-friendly 6809 system I slapped together on the $30 Tang Nano 20K FPGA board.
I always wanted to try a 6809, mainly because it has a User Stack that works perfectly as a Forth Datastack -- complete with push and pull instructions. Unlike all other processors out there.
Well, the 68K allowed any address register to be used as a datastack, I suppose. But the U register is actually designed for Forth.
Anyway, I wrote a bootloader, which initializes the User Stack Pointer, and everything from that point is Forth-like. It also provides basic IO, Forth style, and a few basics, like printing strings and a simple memory dump and a binary loader so I can assemble and send code over RS232.
Forth Advanced Run-Time is almost ready for a Forth.
2025-04-16 · 1 year ago · 👍 drh3xx, wasolili, norayr, lowpass
8 Comments ↓
👽 spc476 · 2025-04-17 at 08:21:
You wouldn't happen to be using the 6809 assembler from https://github.com/spc476/a09, would you? Just curious ...
🐐 drh3xx · 2025-04-17 at 11:19:
sounds like a cool project
🚀 stack [OP/mod] · 2025-04-17 at 13:40:
yes! Is it yours, and was I giving you a hard time?
🚀 stack [OP/mod] · 2025-04-17 at 13:41:
Especially if you read the name as an acronym
👽 spc476 · 2025-04-17 at 20:45:
Yes, it's mine, and no, you weren't giving me that hard of a time. You at least did find two bugs in the assembler.
🚀 stack [OP/mod] · 2025-04-17 at 21:01:
@spc476, thank you again for the assembler. I like it more than a couple of others I tried.
What kind of a 6809 system do you have? Are you working on anything interesting?
👽 spc476 · 2025-04-18 at 00:55:
I have a Tandy Color Computer in storage, so I tend to use either the 6809 emulator I wrote (which is also part of the assembler), or XRoar, a Color Computer emulator.
Besides the assembler, I too, am currently working on a 6809 ANS Forth system, which started out as me trying to figure out how DOES> is implemented.
🚀 stack [OP/mod] · 2025-04-18 at 01:42:
Excellent. If you ever want to put together a 40Mhz 6809 on that $30 board, I'll be happy to assist.