The Mensch computer uses CS0B and CS1B to map 65c22s into memory.
https://www.westerndesigncenter.com/wdc/Mensch_Computer.php
I don’t really see how CS0B can replace ports but port expansion is obvious.
In older documentation CS1B was described as COProcessor expansion; even more mysterious. But in ...

Maybe this? http://biged.github.io/6502-website-arc ... comuf.com/

This thread might be helpful:
viewtopic.php?f=4&t=5698&hilit=W65c816sxb

If you wish to go further into the 65c134 there’s a patent available for reading:
US7123107A which can be found at google patents.
There’s also a variety of patents filed for the 65c265. Search William D. Mensch inventor.

Cheers,
Andy

For the 65816 based Apple IIGS there’s Marinetti.

https://sourceforge.net/projects/marinetti/

Here’s a link I found:

viewtopic.php?f=3&t=5226&p=61648&hilit=Rsc+forth#p61648

Cheers,
Andy

The w65c134s, according to WDC’S data sheet, doesn’t include Rockwell bit manipulation op-codes.

There’s also a redesign of the FPE and Number Cruncher coprocessor cards for the Apple IIe and IIGS here:
https://www.geekdot.com/numbercruncher-reloaded/

Cheers,
Andy

There’s also Merlin 32: http://brutaldeluxe.fr/products/crossdevtools/merlin/

Cheers,
Andy

Historically speaking, there was Rockwell’s RSC FORTH:
viewtopic.php?f=3&t=5226&hilit=Rsc+forth

Cheers,
Andy

The only source I know of is like a 65802; a 65816-6502 board here a2heaven.com.

Cheers,
Andy

Does your custom rom contain values for calculating FCLK over 6 mhz and corresponding baud rates?
The internal rom will default to 3.68 mhz on error.
BTW congrats!

Cheers, Andy

It was nice that WDC provides the source for the ‘265 monitor rom and reference manual. Out of the box the internal rom will start the ‘265 with virtually no resources only what ram, rom and I/O is on the chip. So while WDC ‘reserves’ some things for itself there’s no prohibition for writing your ...

I hardwired a 1.8432mhz oscillator to Timer 4 via P60. Does anyone have any idea how to use this to set the baud rates for, say, Port 3? I know to switch Bit 0 of the Timer Control Register to "1" to use that as TIN. Beyond that, I'm not sure what to do. The documentation isn't clear as to which ...

If one was to turn off CS2B that would pretty much disconnect all of the internal I/O and ram from the core 65c816. The only way I can conceive of reconnecting the internal I/O and ram is reset.

Cheers,
Andy

P.S. Bill Mensch has a number of patents relating to his micro-controllers. I usually use ...