Potential targets

[larsbrinkhoff]

8-bit devices:

• [x] 6502
• [ ] 68HC05/08/RS08
• [x] 8051
• [x] AVR
• [ ] H8/300L
• [x] PIC (just midrange for now)
• [ ] ST6
• [x] STM8

16-bit devices:

• [x] MSP430
• [ ] PIC24 (dsPIC)
• [ ] MAXQ20
• [ ] R8C
• [ ] RL78
• [ ] H8/300H
• [ ] 68HC11/12
• [ ] 68HC16
• [ ] C166/C167/ST10/XE2000

32-bit devices:

• [x] Cortex-M, in particular M0
• [ ] Xtensa (ESP8266)
• [ ] RISC-V
• [ ] PIC32 (MIPS)
• [ ] ARC
• [ ] ColdFire
• [ ] MicroBlaze

[larsbrinkhoff]

Rough plan, subject to changes:

• PDP-8: done.
• Cortex-M: done.
• PDP-1
• Xtensa

[larsbrinkhoff]

PowerPC doesn't seem to be a hot candidate. Parts are "not for new designs" and the smallest program size is 448K which can easily accomodate a resident compiler.

Can't find any SPARC microcontrollers on DigiKey. But I live next doors to the makers of the LEON...

[larsbrinkhoff]

Historical survey: Microcontrollers sold by ELFA in 2005:

• 68HC05/08
• 68HC11
• PIC12/16/18
• Basic Stamp/Atom
• ST6
• ST7
• AVR
• SX
• MSP430
• Z8

[larsbrinkhoff]

I have to take it back about the PowerPC. The e200 series seems to be alive and kicking. Probably on its way out, but still.

[larsbrinkhoff]

Someone asked about C16x/ST10? I'm adding targets if there's a chance someone will use them one day. (Or if they seem interesting to me personally.) I never saw anyone mention C16x or ST10 before. STM seems to classify it as a legacy product.

Availability of parts and evaluation boards is also a factor to consider.

[TG9541]

Hmm.. that was I - until I realized that those were already listed. I once worked a lot with C16x, ST10F269, ST10F276, and I also did some XE2000 coding. The instruction set should be well suited for a Forth kernel. But you're right, these µCs are a thing of the past, just like GSM phones ;-)

[larsbrinkhoff]

I don't see any tiny MIPS devices. The PIC32 ones are smallish.

This one isn't small except in physical dimensions. Still nice:
http://vocore.io/v2.html

[TG9541]

Well, I guess it's sufficient to run 256 interactive Forth consoles, with a generous helping of RAM each, concurrently.

[larsbrinkhoff]

640KB ought to be enough for anybody.

EDIT: For ten anybodies - if they're forthers!

[TG9541]

Yes. My Life in a Terabyte is my witness.

[larsbrinkhoff]

TMS320 DSPs?

There's a plethora of parts. I can't even begin to list them.

• C2000 series - 32 and 16 bit fixed point.
• C5000 series - 16-bit.
• C6000 series - VLIW, fixed and floating point.

At least for the C28x 32-bit family, there are inexpensive Launchpad boards.

I already have a C55x board, because I ordered the wrong thing when I was getting an MSP430 Launchpad.

[larsbrinkhoff]

There are also Launchpad boards with Cortex-R parts.

[larsbrinkhoff]

Good article:
https://jaycarlson.net/microcontrollers/

Mentions the LC87.

[sbridger]

I think that the PIC16F1XXX enhanced midrange would be sufficient. They are cheaper than any older midrange parts, more capable, and pretty much completely overlap the pinouts and capabilities. (perhaps with the exception of some 6 pin parts. But what could you connect the tether to?)

The twin pointers and larger stack should make them significantly better forth targets I would think.

Also, unlike many other current processors, some of the 8 and 14 pin parts have such small flash space tethered forth may be the only choice.

[larsbrinkhoff]

I already support the original midrange PIC, so I'm guessing (without having checked) that adding the enhanced parts to the zoo wouldn't bee too hard.