FLEX for the 6502 or building a compatible operating system...

[BillG]

19 hours ago, JamesD said:

Deciding on the memory map is tough.  Once you set it in stone you are stuck with it, so you want to get it right.

That is why I chose to spend so much time developing programs for FLEX - to help finalizing the memory map.

[BillG]

19 hours ago, JamesD said:

I searched for LUCIDATA Pascal and found where you've been posting, and your Github page.
That should work nicely.  In the search I ran across an article in a Heathkit related 1988 newsletter that mentions it was released into the public domain.
I spent several hours porting the UCSD P-Machine to the 6803.  About all I had left was the hardware specific changes, but I had to migrate machines, and the code is... um... currently misplaced.
I wanted to change the UCSD environment so it supported a shell where you could add commands or programs run from the command line under the P-Machine.
That way the system could be expanded easily, and it could run advanced commands that would otherwise require too much memory.

I found some of those Heath newsletters.

 

There was mention of a program to convert a P-code program to assembly language.  As far as I know, nothing like that was ever available for FLEX.

 

I steered away from UCSD for one huge reason - it is still under copyright.  I would hate to spend a bunch of time on something then get a cease and desist to stop using it.  That plus it lived in its own world and there was no way to run "foreign" programs.

[JamesD]

10 hours ago, BillG said:

I found some of those Heath newsletters.

 

There was mention of a program to convert a P-code program to assembly language.  As far as I know, nothing like that was ever available for FLEX.

 

I steered away from UCSD for one huge reason - it is still under copyright.  I would hate to spend a bunch of time on something then get a cease and desist to stop using it.  That plus it lived in its own world and there was no way to run "foreign" programs.

The 6800 is pretty difficult to target with stack based languages.  You can't even push/pull the X register.
Not too worried about UCSD.  Wish em the best of luck proving damages, and worst case, I distribute a source file which is protected speech here in the US.  I wrote 100% of the 6803 code.
 

[BillG]

4 hours ago, JamesD said:

The 6800 is pretty difficult to target with stack based languages.  You can't even push/pull the X register.
Not too worried about UCSD.  Wish em the best of luck proving damages, and worst case, I distribute a source file which is protected speech here in the US.  I wrote 100% of the 6803 code.
 

6502 is worse, with only 256 bytes max for the hardware stack.

 

If it was only for personal use, I would not worry about UCSD copyrights.  But if I have any intent of someone else adopting it, I choose things already in the public domain like FLEX and LUCIDATA.  And CP/M, though technically still copyrighted, is essentially public domain unless I am trying to make money selling copies of it.