Search found 31 matches

by qwertyface
05 Jul 2021, 13:04
Forum: Hardware and software hacking
Topic: Additional facilities for native code programming / a new SYS function calling convention
Replies: 3
Views: 420

Re: Additional facilities for native code programming / a new SYS function calling convention

Thanks for taking the time to reply - I'm glad that you don't think my thoughts are completely crazy! I still want to have a play with this idea, but it's about three down on my stack of Gigatron things I want to do. I see a couple of major issues with the approach I described above: If we imagine t...
by qwertyface
24 Jun 2021, 12:09
Forum: Hardware and software hacking
Topic: Additional facilities for native code programming / a new SYS function calling convention
Replies: 3
Views: 420

Additional facilities for native code programming / a new SYS function calling convention

Hi everyone, I've been pondering a bit on the native-code / SYS function interface, and if and how it could be changed to support a more structured style of native-code programming. I'm largely just writing this to get these ideas out of my head (where they've been quite distracting). I think this i...
by qwertyface
22 Jun 2021, 08:12
Forum: Hardware and software hacking
Topic: New vCPU instructions 2.0
Replies: 91
Views: 11106

Re: New vCPU instructions 2.0

Yes, I think to do both bytes and the transfer in 30 is not possible. If you could do it in two-phases it should work (but how would you dispatch to different code the on the second and subsequent calls?). My implementation of Arithmetic shift-right is 45 excluding the cost of dispatch and I thought...
by qwertyface
21 Jun 2021, 08:56
Forum: Hardware and software hacking
Topic: New vCPU instructions 2.0
Replies: 91
Views: 11106

Re: New vCPU instructions 2.0

Nice. Looping works out an awful lot smaller than trying to do the whole thing in one go, and will win in cost in a lot of cases. Are you planning to do the same thing for logical and arithmetic right shift? The same broad approach would work, but the cost of repeatedly entering the right-shift tabl...
by qwertyface
15 May 2021, 07:25
Forum: Hardware and software hacking
Topic: GtForth - Forth on top of the vCPU
Replies: 9
Views: 958

Re: GtForth - Forth on top of the vCPU

I am still far from understanding the big picture though... How do you plan to implement the words? Are you going to implement the full set of words of the Forth standard in native code (ROM)? It's hard to see the big picture when it's only half drawn. :D In ROM, yes, in native code, no. To the ext...
by qwertyface
15 May 2021, 03:51
Forum: Hardware and software hacking
Topic: Expanding ROM space
Replies: 7
Views: 831

Re: Expanding ROM space

It's an interesting idea, but I'm not sure that it works in practice. For one thing, you can't really get out of the page without setting y. You also can't practically write much native code without writing to page zero. Bear in mind that the packing density also depends on the amount of the page gi...
by qwertyface
14 May 2021, 08:33
Forum: Hardware and software hacking
Topic: GtForth - Forth on top of the vCPU
Replies: 9
Views: 958

Re: GtForth - Forth on top of the vCPU

Also having the vCPU emulator helped me test the system more quickly. I've also benefited from using an emulator for testing. I've got pytest/hypothesis unit tests for all of the words that I've implemented, most of which are written in a fairly high-level way . Perhaps this is something that we co...
by qwertyface
13 May 2021, 21:27
Forum: Hardware and software hacking
Topic: GtForth - Forth on top of the vCPU
Replies: 9
Views: 958

Re: GtForth - Forth on top of the vCPU

This is really cool, congratulations! It must have been a ton of work. If I may say so, it's lovely neat source as well. I'm sure I have a lot to learn from it, in particular the work on how the Python assembler module packs code into memory. I also like your approach to self-hosting. For obvious re...
by qwertyface
04 May 2021, 11:10
Forum: Hardware and software hacking
Topic: New vCPU instructions 2.0
Replies: 91
Views: 11106

Re: New vCPU instructions 2.0

Just a couple of comments: I see you've moved code some code to page 0. If I ever complete and merge my Forth, I need a short routine in page 0 (currently 5 instructions). Could you try to leave at least that much space for my purposes? The location isn't important. I see that you're making changes ...
by qwertyface
02 Dec 2020, 10:15
Forum: Hardware and software hacking
Topic: List of possible Gigatron mods
Replies: 14
Views: 3471

Re: List of possible Gigatron mods

This got me thinking. Who else has written (native) code for the Gigatron? Obviously Marcel and there is one other project I'm aware of - https://hackaday.io/project/168293-gigatron-forth Working directly with the op-codes is a significant undertaking and it looks like the Gigatron Forth project mi...