Search found 488 matches
- 16 Feb 2020, 23:31
- Forum: Hardware and software hacking
- Topic: Expansion bus
- Replies: 98
- Views: 101037
Re: Expansion bus
If there's another master on the i2c bus, there isn't much we can do. As I understand it, we have to become responsive to its clock. That's the same problem we faced with PS/2 and that we ran away from. But given that SPI software support is still ploughing on I believe we have time to get it right....
- 16 Feb 2020, 22:00
- Forum: Hardware and software hacking
- Topic: associate the .gt1 filetype for web autoloading
- Replies: 8
- Views: 10168
Re: associate the .gt1 filetype for web autoloading
Maybe you need to explain a bit more. Is that something you have experience with applying in a similar context? Is it your project?ECL wrote: ↑16 Feb 2020, 21:24 https://addons.thunderbird.net/en-US/th ... hunderlink
could be useful as a basis for implementing such .gt1 links
- 15 Feb 2020, 16:49
- Forum: Escape Meta Alt Control Shift
- Topic: Discrete transistor computers
- Replies: 2
- Views: 7667
Discrete transistor computers
Homebrew CPU wisdom dictates that discrete transistor computers must be much slower than TTL computers. "Due to capacitances and noise levels", as people usually put it. The MT15, Megaprocessor and Monster6502 are then given as examples. After all, each of those max out well below 1 MHz. H...
- 15 Feb 2020, 14:22
- Forum: Hardware and software hacking
- Topic: Expansion bus
- Replies: 98
- Views: 101037
Re: Expansion bus
Do you mean that any i2c transfer shouldn't be operated in parallel with SPI0/1 activity? That's not an unreasonable constraint. If software can handle it, there's no need to add hardware for it. The mantra still stands. Anyway, in this schematic, SS2/3 must be kept low during SPI transfer so that M...
- 11 Feb 2020, 19:38
- Forum: Hardware and software hacking
- Topic: Expansion bus
- Replies: 98
- Views: 101037
Re: Expansion bus
Don't trust the output too much :-). This is still code that was supposed to work on one specific card I had at hand. And it appears to work on several, but for the wrong reason. I best address it when I can resume with the GTOS shell. I like the idea of turning 2 of the ports into a single i2c port...
- 10 Feb 2020, 22:38
- Forum: Hardware and software hacking
- Topic: GTOS
- Replies: 4
- Views: 6586
Re: GTOS
From skimming over the older CardTest code, I conclude that byte addressing isn't detected correctly. And even it if were, it wouldn't work anyway, because the way it is handled further on isn't correct. I believe this is consistent with the observations so far, including jwolfram's today. This is p...
- 10 Feb 2020, 11:24
- Forum: Hardware and software hacking
- Topic: Expansion bus
- Replies: 98
- Views: 101037
Re: Expansion bus
That's more than likely the same software issue mentioned in the GTOS thread:
https://forum.gigatron.io/viewtopic.php?p=1215#p1215
I haven't found time to dive into it yet...
[Edit: created GitHub issue: https://github.com/kervinck/gigatron-rom/issues/161]
https://forum.gigatron.io/viewtopic.php?p=1215#p1215
I haven't found time to dive into it yet...
[Edit: created GitHub issue: https://github.com/kervinck/gigatron-rom/issues/161]
- 08 Feb 2020, 16:45
- Forum: Hardware and software hacking
- Topic: Interrupts:
- Replies: 11
- Views: 13296
Re: Interrupts:
Consider it done and tested: vertical blank interrupts now work fine in dev.rom. They trigger at the top of vertical blank whenever frameCount overflows to 0 and the vIRQ vector is non-zero. This vector must point to vCPU code. vPC and vAC will already be saved in the top of the zero page. The "...
- 08 Feb 2020, 14:37
- Forum: Hardware and software hacking
- Topic: v6502 mini-assembler in Apple-1 emulator
- Replies: 3
- Views: 6502
Re: v6502 mini-assembler in Apple-1 emulator
The mini-assembler now has its entry point moved to $EEE because that's easier to remember than $D13. So from wozmon you enter its `!'-prompt with: EEER The I/O (keyboard, display) is now handled by PIA chip emulation instead of the v6502 BRK instruction. In the original Apple-1, all I/O goes throug...
- 03 Feb 2020, 14:06
- Forum: Hardware and software hacking
- Topic: associate the .gt1 filetype for web autoloading
- Replies: 8
- Views: 10168
Re: associate the .gt1 filetype for web autoloading
While we try to use little-endian where possible, for practical reasons GT1 segment headers are big-endian. Details are in Docs/GT1-files.txt
You seem to know how to do this, so the usual applies: good idea, don't wait for others to pick it up and feel free to go ahead!
You seem to know how to do this, so the usual applies: good idea, don't wait for others to pick it up and feel free to go ahead!