Search found 1355 matches

by Jubatian
Thu May 16, 2019 7:37 pm
Forum: Uzebox Derivatives & open source consoles
Topic: Pozitron
Replies: 10
Views: 1368

Re: Pozitron

Huh, thanks! Sorry, I might have been ambiguous when talking about emulation. I didn't want that to come through as you or anyone aimed for true AVR emulation on the ARM. As far as I am aware, that would need at least ~700MHz ARM assuming a Cortex-M3 like architecture & timing. I was referring to em...
by Jubatian
Wed May 15, 2019 10:44 pm
Forum: Uzebox Derivatives & open source consoles
Topic: Pozitron
Replies: 10
Views: 1368

Re: Pozitron

Tossing a bit of thought and theoretical video mode assembly design at it, I think it is totally feasible to get a good 6 x NTSC (21MHz) colorburst solution on this HW, capable to recompile Mode 1 / 3 Uzebox games to it. By the assumption that you lay out Video out so it is BBGGGRRR on the low 8 bit...
by Jubatian
Wed May 15, 2019 9:29 pm
Forum: Uzebox Derivatives & open source consoles
Topic: Pozitron
Replies: 10
Views: 1368

Re: Pozitron

Could be an interesting project indeed! 64K RAM might actually be enough to get a decent Uzebox port going which doesn't need reflashing, which could be a nice plus (unbounded lifetime). The ARM versus 8 bit AVR from my perspective boils down to these problems: No DIP solution, although for sure the...
by Jubatian
Wed May 15, 2019 8:31 pm
Forum: Programming & Software
Topic: New bootloader
Replies: 127
Views: 24253

Re: New bootloader

I'm not concerned enough (not at all. it's ridiculously old, pretty sure no cards on the market have been this slow for 7+ years.) to setup building the bootloader to fix it just yet but I can test. It could be interesting to give it a go, just to see how it fails, maybe the bootloader could be twe...
by Jubatian
Sun May 12, 2019 9:16 am
Forum: Programming & Software
Topic: New bootloader
Replies: 127
Views: 24253

Re: New bootloader

Which games? It may be okay for smaller chunks, the failure is roughly after 32KB. Maybe there's some buffer underrun with those cards then. It seems like then communicating with SPI might be fine at higher speed, but the card can not fetch data fast enough, possilby manifesting in long waiting on ...
by Jubatian
Sat May 11, 2019 8:00 pm
Forum: Programming & Software
Topic: New bootloader
Replies: 127
Views: 24253

Re: New bootloader

It's slow because the MMC cards I have don't support the higher clock speed. Programming fails during download. So I left it with the default speed. Wow, and I was thinking I was driving them slow. At least definitely compared to Tempest or in general how it was typically with the original kernel (...
by Jubatian
Sat May 11, 2019 8:01 am
Forum: Programming & Software
Topic: New bootloader
Replies: 127
Views: 24253

Re: New bootloader

The filter is just for .uze files correct? I ask because some games use _HISCORE.DAT as a data file. It doesn't affect games anyhow, not even those which would use the bootloader interface for SD, it is just the game selector's filter determining from which files it assembles the game list. This fi...
by Jubatian
Fri May 10, 2019 7:03 pm
Forum: Programming & Software
Topic: New bootloader
Replies: 127
Views: 24253

Re: New bootloader

fdisk wouldn't let me start the partition at "sector" 63 but whatever, I nulled the SD card (TAKE THAT, WRITE CYCLES! NO 0xFF FOR YOU) so it compresses well. Thank you! Finally a bit of good old productive bugfixing :) Simply ignoring dotfiles should help. How do we do that in 3 byte? Eh, I almost ...
by Jubatian
Thu May 09, 2019 7:58 pm
Forum: Programming & Software
Topic: New bootloader
Replies: 127
Views: 24253

Re: New bootloader

Thank you, I thought about asking for a disk dump myself, but realized the same quickly, it may need an unreasonably large dump to have a good chance of getting the root directory data in it.
by Jubatian
Wed May 08, 2019 11:02 pm
Forum: Programming & Software
Topic: High resolution ROM/RAM tiles attribute mode
Replies: 4
Views: 645

Re: High resolution ROM/RAM tiles attribute mode

What is your "ideal" video mode for this large game? It sounds like low RAM usage may be one of the things and that is a hard one. Yes, low RAM usage is a primary concern, but low ROM usage is also important. I would like to get good diversity, attribute modes work well for that as they permit dist...