Search found 239 matches

by lb3361
07 Dec 2022, 13:57
Forum: Hardware and software hacking
Topic: ROMv5 ?
Replies: 9
Views: 231

Re: ROMv5 ?

The purpose of this thread was to discuss what to do now that we essentially have what Marcel had planned for v5. This was intended to be purely technical but that was maybe premature. In relation to at67's post, there are in fact two questions to answer: Should there be a v5 release now that Marcel...
by lb3361
07 Dec 2022, 00:02
Forum: Hardware and software hacking
Topic: An ominous warning and a hardware puzzle
Replies: 0
Views: 41

An ominous warning and a hardware puzzle

The first three multiplexer inputs are tied to the instruction bits that determine when a branch should occur. For instance 100 means BGT, 110 means BNE, etc. For an unconditional branch, the instruction bits are 111. I maintain an experimental rom to play with all kind of crazy idea. I am particula...
by lb3361
06 Dec 2022, 18:16
Forum: Hardware and software hacking
Topic: ROMv5 ?
Replies: 9
Views: 231

Re: ROMv5 ?

veekoo wrote: 04 Dec 2022, 06:21 How is Pluggy Reloaded, does it work then with new release?
It certainly works with the current dev rom. Since this is a popular add-on, it would make sense to have a version of the browser in the ROM. I believe one needs a version that fails more gracefully in the absence of a Pluggy Reloaded.
by lb3361
05 Dec 2022, 20:43
Forum: Hardware and software hacking
Topic: ROMv5 ?
Replies: 9
Views: 231

Re: ROMv5 ?

On my own behalf, I'd quite like to get a SYS_MultiplyBytes into a future ROM version. There is already a SYS_Multiply_s16, written by at67, that multiplies two 16 bits numbers, returning the low 16 bits of the result. Of course one could improve its implementation in the future to make it much fas...
by lb3361
30 Nov 2022, 16:50
Forum: Hardware and software hacking
Topic: ROMv5 ?
Replies: 9
Views: 231

ROMv5 ?

I believe it is time to consider the release of a true ROMv5 because most of what Marcel has envisioned for ROMv5 has been achieved (see https://github.com/kervinck/gigatron-rom/blob/2d2ec7d35b8d37940faccbd7b7bf3b10cf19f916/Core/dev.asm.py#L91 and compare with https://github.com/kervinck/gigatron-ro...
by lb3361
21 Nov 2022, 23:32
Forum: Hardware and software hacking
Topic: Unified return from vCPU interrupt (vRTI)
Replies: 6
Views: 246

Re: Unified return from vCPU interrupt (vRTI)

Created pull request https://github.com/kervinck/gigatron-rom/pull/242. Let's see what at67 thinks! This includes a comment and new interface.json variables 'userVars_vX' clarifying the boundary above which programs can use zero page bytes. Here is the full comment # Management of free space in page...
by lb3361
21 Nov 2022, 01:25
Forum: Hardware and software hacking
Topic: Unified return from vCPU interrupt (vRTI)
Replies: 6
Views: 246

Re: Unified return from vCPU interrupt (vRTI)

Conclusion. I tend to believe one should bite the bullet and reserve two more bytes for saving the vIRQ state. One should do this even if we do not implement the unified vRTI because future developments will need for space in page zero and one needs to define clear rules about which zero page locati...
by lb3361
21 Nov 2022, 00:26
Forum: Hardware and software hacking
Topic: Gigatron emulator for MorphOS system
Replies: 6
Views: 156

Re: Gigatron emulator for MorphOS system

Ad1. I solved the problem. Youre right i must send ASCII codes, buf for cursor keys i must send codes 0, 1, 3, 7. Cursor keys are in fact the same as the famicom arrow keys. The whole situation is in fact a bit of a mess... The default state is 0xff which means that nothing is happening. In theory,...
by lb3361
19 Nov 2022, 13:36
Forum: Hardware and software hacking
Topic: Gigatron emulator for MorphOS system
Replies: 6
Views: 156

Re: Gigatron emulator for MorphOS system

1. How send to Gigatron core information about key from pad or keyboard? i mean: what is the transmission protocol? Set variable IN to the ASCII code of the key for two screen frames, then reset it to 0xff. https://github.com/kervinck/gigatron-rom/blob/master/Docs/gtemu.c#L11 2. I will try change s...
by lb3361
19 Nov 2022, 04:04
Forum: Hardware and software hacking
Topic: Unified return from vCPU interrupt (vRTI)
Replies: 6
Views: 246

Re: Unified return from vCPU interrupt (vRTI)

Turns out that there was a solution that does not involve tapping the reserved variable at address 0x04. This new version saved vPC in $30-$31, vCpuSelect in $32, and pushes vAC on the stack. Location $33 is reserved for now. This code is tricky because restoring the context takes 10 more cycles. If...