Search found 235 matches

by lb3361
30 Nov 2022, 16:50
Forum: Hardware and software hacking
Topic: ROMv5 ?
Replies: 3
Views: 86

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: 217

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: 217

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: 5
Views: 105

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: 5
Views: 105

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: 217

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...
by lb3361
11 Nov 2022, 22:19
Forum: Hardware and software hacking
Topic: Unified return from vCPU interrupt (vRTI)
Replies: 6
Views: 217

Re: Unified return from vCPU interrupt (vRTI)

Turns out that gtBasic programs compiled for ROMv5a and using "INIT TIME" or "INIT MIDI" are only avoiding the vIRQ locations $30 to $33. This means that these programs can use $34 as the low byte of an integer variable. I would want these programs to work unchanged on the DEVROM...
by lb3361
11 Nov 2022, 14:32
Forum: Kit assembly gallery
Topic: New one Gigatron in Poland
Replies: 4
Views: 165

Re: New one Gigatron in Poland

The memory expander looks neat! What do you propose as the next extension I am quite partial, but you might find interesting to build a 128kb ram and IO extension, https://forum.gigatron.io/viewtopic.php?p=2047#p2047, then try to browse a sdcard attached to the spi bus, https://forum.gigatron.io/vie...
by lb3361
10 Nov 2022, 15:42
Forum: Hardware and software hacking
Topic: Unified return from vCPU interrupt (vRTI)
Replies: 6
Views: 217

Re: Unified return from vCPU interrupt (vRTI)

It looks good to me, as long as it passes compatibility tests I think it's a definite improvement. Thanks. The only program that seriously exercises vIRQ+v6502 is the Apple1 emulator and it works perfectly fine. I also successfully tried some of my programs that use vIRQ with vCPU only. At67, can y...
by lb3361
10 Nov 2022, 04:31
Forum: Hardware and software hacking
Topic: Unified return from vCPU interrupt (vRTI)
Replies: 6
Views: 217

Unified return from vCPU interrupt (vRTI)

The gigatron virtual interrupt system (see https://github.com/kervinck/gigatron-rom/blob/master/Docs/Interrupts.txt) is a bit complicated because there are two ways to return from an interrupt. There is a fast way (LDWI $400 LUP 0) which does not save the current interpreter and therefore cannot wor...