Search found 7 matches

by DavidS
Sat Nov 16, 2013 5:55 pm
Forum: Pi
Topic: 26bit CPU support
Replies: 13
Views: 10984

Re: 26bit CPU support

I have almost got my code cleaned up enough to show off what is working. So it should not be long before I have something to show off, I hope. The system is fairly simple at this time: A module that does the actual translation, and will be extend for more things. The module filename is 26Bitter, the...
by DavidS
Tue Nov 12, 2013 7:34 pm
Forum: General
Topic: Raspberry Pi compatibility
Replies: 6
Views: 9899

Re: Raspberry Pi compatibility

Off the top of my head: 1. Zarch - has self modifying code, writes directly to the RISCOS 3.1 screen memory and doesn't touch VIDC registers 2. Pacmania - no self modifying code, writes to the current screen memory and uses a 4-bit mode. Doesn't alter VIDC parameters 3. Elite - no self modifying co...
by DavidS
Tue Nov 12, 2013 7:25 pm
Forum: Pi
Topic: 26bit CPU support
Replies: 13
Views: 10984

Re: 26bit CPU support

David - we'll need to use B instead or BL to avoid R14 corruption and B explicitly to the next instruction on return. Yes we shall I made that post a bit to quickly, my appologies. Self-modifying code, I'll write up my notes when I get a chance, in short my idea was to leave all RAM as read/write, ...
by DavidS
Tue Nov 12, 2013 7:22 pm
Forum: Pi
Topic: 26bit CPU support
Replies: 13
Views: 10984

Re: 26bit CPU support

What follows is a quick overview of how I am looking at the implementation of a translator for running 26bit code on 32bit only ARM CPUs. This is only a quick foot note version quickly compiled from my source code, so any inacuracies are the result of reading my own source to quickly. Thus said I th...
by DavidS
Tue Nov 12, 2013 6:40 pm
Forum: Pi
Topic: 26bit CPU support
Replies: 13
Views: 10984

Re: 26bit CPU support

The target is to include cortex CPUs and should work well on the XScale and even SA110, ARM710, ARM610 etc in 32Bit mode as well. Or at least this is my understanding and what I am aiming for. We will see what Jon jas to say though/ Though it should be noted that these CPUs are similar enough that t...
by DavidS
Tue Nov 12, 2013 4:53 pm
Forum: Pi
Topic: 26bit CPU support
Replies: 13
Views: 10984

Re: 26bit CPU support

I am rewriting my JIT for your use and adding support for VIDC1/1a/2/20 as I go. Also your list of instructions is a bit incomplete do not forget: CMPP, TEQP, TSTP,CMNP. I am currently working on getting it working by replacing most ops with compatable OPs and using a small area of code at another l...
by DavidS
Tue Nov 12, 2013 4:43 pm
Forum: General
Topic: Raspberry Pi compatibility
Replies: 6
Views: 9899

Re: Raspberry Pi compatibility

Hello I am very interested in getting the emulation working starting from a hack that I had thrown togather in order to run some 26Bit software i am currently rewriting this to work with more software and be a bit more effecient. Also looking into methods of simulating the old HW on the newer boards...