Search found 645 matches

by at67
16 Mar 2021, 12:04
Forum: Hardware and software hacking
Topic: New vCPU instructions 2.0
Replies: 95
Views: 47957

Re: New vCPU instructions 2.0

Cheers Walter!

Update:

Don't write code when you are tired, if you do...sleep on it and then check it in the morning...before making forum posts about it.
  • POKEV removed as it was totally pointless...
We're back to one free instruction slot.
by at67
16 Mar 2021, 04:16
Forum: Hardware and software hacking
Topic: New vCPU instructions 2.0
Replies: 95
Views: 47957

Re: New vCPU instructions 2.0

Update:

Fill the remaining free instruction slot with:
  • POKEV writes the byte contained in vAC.lo to the address contained in the zero page variable [var], 28 cycles
by at67
14 Mar 2021, 22:19
Forum: Kit assembly gallery
Topic: And again a new Gigatron fan
Replies: 15
Views: 12394

Re: And again a new Gigatron fan

Thanks for this information. The XOR and sprite thing is of course very dependent on the colors and background. I still have a lot to learn about the Gigatron, I've only known it for 3 months. After the hardware, I want to get more involved with programming the Gigatron. I find the emulator from at...
by at67
14 Mar 2021, 00:48
Forum: Hardware and software hacking
Topic: New vCPU instructions 2.0
Replies: 95
Views: 47957

Re: New vCPU instructions 2.0

Update: I managed to find another 2 instruction slots by optimising instructions that weren't returning to NEXTY and that had a 3 instruction prologue, (this set of circumstances allows those instructions to be moved to 2 instruction prologue opcodes). I also tried to optimise the more commonly use...
by at67
12 Mar 2021, 11:24
Forum: Hardware and software hacking
Topic: New vCPU instructions 2.0
Replies: 95
Views: 47957

Re: New vCPU instructions 2.0

Update: ANDB was removed ORB was removed XORI was moved from an external page back to page3, cycle time was decreased from 20 back to 14 I fell for the same trap a second time...thinking I could move XORI out of page 3 to make room for more instructions, the instruction following XORI is BRA; it mo...
by at67
11 Mar 2021, 21:37
Forum: Hardware and software hacking
Topic: New vCPU instructions 2.0
Replies: 95
Views: 47957

Re: New vCPU instructions 2.0

Update: Thanks to lb3361 for the idea of a more formal and consistent naming scheme: NOTB was removed XORB was removed XORI was moved from page3 to an external page, cycle time increased from 14 to 20 MOVBA was renamed to MOVA MOVB was renamed to MOV LDQW was renamed to MOVQW LDQ was renamed to MOV...
by at67
11 Mar 2021, 21:21
Forum: Hardware and software hacking
Topic: New vCPU instructions 2.0
Replies: 95
Views: 47957

Re: New vCPU instructions 2.0

The problem is that sys calls (especially the long ones) do not schedule as well as short instructions. The VCPU might stall until one reaches a blank That's true to some extent, but the advantage of sys calls is that the more densely you compress the call with the equivalent functionality of separ...
by at67
11 Mar 2021, 02:00
Forum: Hardware and software hacking
Topic: New vCPU instructions 2.0
Replies: 95
Views: 47957

Re: New vCPU instructions 2.0

I'd be surprised if you didn't have these problems in Basic as well to some level. I do have these issues, I use helpers like these, (their function pointers live in zero page RAM rather than needing the LDWI/CALL thunk for ROM's < 5a): %SUB convert8Arr2d convert8Arr2d ADDW memIndex0 ADDW memIndex0...
by at67
10 Mar 2021, 20:44
Forum: Escape Meta Alt Control Shift
Topic: A monthly Gigatron meetup on Zoom.
Replies: 4
Views: 5752

Re: A monthly Gigatron meetup on Zoom.

That sounds like a great idea, I'm not sure I could attend regularly, (I think that's around 3:00am my time), but I could try and show up every now and then.
by at67
10 Mar 2021, 20:27
Forum: Hardware and software hacking
Topic: New vCPU instructions 2.0
Replies: 95
Views: 47957

Re: New vCPU instructions 2.0

I was mostly thinking about what's needed to resurrect the C compiler to be honest. The main issues for a C compiler are to make sure we can do move things around easily, and in particular easily enough to deal with real stack frames. Otherwise the needs are similar to those of Basic I believe. Per...