Search found 54 matches

by dentnz
Sat Aug 14, 2021 11:41 pm
Forum: Display Devices
Topic: Scaler won't downscale
Replies: 9
Views: 2825

Re: Scaler won't downscale

Instead of interpolation, wouldn’t it be just ok to skip pixels? Surely this would mean you would be able to read one pixel per cycle, and even skip vertical lines?
by dentnz
Fri May 21, 2021 1:40 am
Forum: SNES (Super Nintendo Entertainment System)
Topic: MSU-1
Replies: 121
Views: 107347

Re: MSU-1

I've started to get somewhere with the EXT_BUS change. Basically, I have copied the MegaCD changes into the SNES core AND Main_MiSTer relating to using the EXT_BUS. From there, I setup some keyboard listening in the FPGA to detect and send a 'command' across the EXT_BUS. The Linux side detects a command request, and responds with a 'status'. The FP...
by dentnz
Wed May 12, 2021 5:14 am
Forum: SNES (Super Nintendo Entertainment System)
Topic: Sufami Turbo Support
Replies: 10
Views: 11866

Re: Sufami Turbo Support

Perhaps instead of the FPGA dealing with the bios and two carts, you might be able to assemble an appropriate rom on the linux side. The rom could include the combination of BIOS, BIOS and ROM SLOT 1, BIOS and ROM SLOT 1 and SLOT 2. I believe this is how some flashcarts are used to play these roms, right?
by dentnz
Tue Apr 27, 2021 2:51 am
Forum: General Discussions
Topic: Just a thought on Downscaler/GBS Control and MiSTer
Replies: 14
Views: 5107

Re: Just a thought on Downscaler/GBS Control and MiSTer

The MiSTer doesn't have a fast enough video conversion capability and would require an additional IO board of some kind, probably with a video-specific IC. At that point, you may as well get a GBS board and make the necessary changes to give it GBSControl capabilities.
by dentnz
Sun Apr 25, 2021 11:04 pm
Forum: SNES (Super Nintendo Entertainment System)
Topic: MSU-1
Replies: 121
Views: 107347

Re: MSU-1

@rahzadan... Unfortunately not. Recently I spoke with Rysha on Discord, and she indicated that I would need to change the approach I have used before it would be accepted into the main code by Sorgleig. The bad news is that it's basically a rewrite... The good news is that it will be a much better solution in the long run. It would also be more lik...
by dentnz
Mon Apr 19, 2021 11:14 pm
Forum: Linux
Topic: MiSTer Streaming Script (OBS/SLOBS) - Update!
Replies: 20
Views: 21904

Re: MiSTer "Listener" Script on PC (Feasible?)

You can run the MiSTer binary and pipe it's console output to a file. You could then quite easily create a tail on that file, parsing it for keywords and performing actions from there. As cores change and roms are loaded, that information is output by the binary, so everything should be there for you to work with. Definitely use that tty2 as a basi...
by dentnz
Mon Mar 22, 2021 5:29 am
Forum: Commodore 16, 64, 128, VIC-20, PET
Topic: A matter of Bits and Cartridges.
Replies: 27
Views: 12771

Re: A matter of Bits and Cartridges.

Oh yeah, I just remembered I hadn't posted an update. Here's a video I made last Friday:

https://www.youtube.com/watch?v=xuXIE-egRrY

There's some kind of off by one error, either it's not getting ALL the bytes, or it's missing the first byte somewhere along the line. I will keep investigating.
by dentnz
Mon Mar 15, 2021 2:00 am
Forum: Commodore 16, 64, 128, VIC-20, PET
Topic: A matter of Bits and Cartridges.
Replies: 27
Views: 12771

Re: A matter of Bits and Cartridges.

SDRAM memory masking - This is now fixed. Writes to REU are out of the way of the 64k ram/rom the CPU can see. Reading back into the standard c64 area seems to work. Counts - Seem to be fixed, albeit the length count returns to 01 still. Perhaps that's intended behavior, as it's what the Ultimate1541 REU does... Though I have read that compatibilit...
by dentnz
Thu Mar 11, 2021 10:50 pm
Forum: Commodore 16, 64, 128, VIC-20, PET
Topic: A matter of Bits and Cartridges.
Replies: 27
Views: 12771

Re: A matter of Bits and Cartridges.

Here's a video updating where things are at: https://www.youtube.com/watch?v=S-PBR4Ti1OI Still a bit more work before I start to test on real examples: - SDRAM memory masking - Seems that transfers to the REU are going into the same RAM that is read by the C64. Need to make sure that the location in SDRAM is out of reach of the CPU. - Buggy transfe...
by dentnz
Sat Mar 06, 2021 6:55 am
Forum: Commodore 16, 64, 128, VIC-20, PET
Topic: A matter of Bits and Cartridges.
Replies: 27
Views: 12771

Re: A matter of Bits and Cartridges.

It’s probably not that tricky for some people. But immensely educational for me. I think I found what I was doing wrong with the read write parts of my finite state machine, but will take a look at it early next week.will keep you updated. After this I want to go back to msu1 audio.
by dentnz
Thu Mar 04, 2021 9:26 pm
Forum: Commodore 16, 64, 128, VIC-20, PET
Topic: A matter of Bits and Cartridges.
Replies: 27
Views: 12771

Re: A matter of Bits and Cartridges.

Things are still progressing.. The Ultimate 1541 has be coaxed into working within the existing core and I am starting to see bytes being read out of c64 RAM without causing a crash. Still haven't been successful on writing them back the otherway unfortunately: https://media.discordapp.net/attachments/661313121453080616/816885800682651658/unknown.p...
by dentnz
Wed Feb 24, 2021 11:41 pm
Forum: Commodore 16, 64, 128, VIC-20, PET
Topic: A matter of Bits and Cartridges.
Replies: 27
Views: 12771

Re: A matter of Bits and Cartridges.

So good progress with the 1541 ultimate REU implementation. I was able to get it to boot (dma_n signal was defaulting to 0) and eventually got the register reads and writes working. I am now working on the transfers themselves. The 1541 code is actually a lot cleaner and bug free. It is in vhdl, so I am having to convert the format of the signals b...
by dentnz
Wed Feb 24, 2021 3:10 am
Forum: Commodore 16, 64, 128, VIC-20, PET
Topic: A matter of Bits and Cartridges.
Replies: 27
Views: 12771

Re: A matter of Bits and Cartridges.

So I eventually came to the realisation that I was effectively rewriting the existing REU code I was using to be non-tristate. And from there, I realised that the 1541 Ultimate implementation is possibly a better match. I am in the process of getting it integrated into the core now. It should make it easier to deal with the SDRAM reading/writing. R...
by dentnz
Mon Feb 22, 2021 4:04 am
Forum: Commodore 16, 64, 128, VIC-20, PET
Topic: A matter of Bits and Cartridges.
Replies: 27
Views: 12771

Re: A matter of Bits and Cartridges.

I don't think the original author of the core implemented hardware pull-up logic in any of the core. You'll probably have to invert those what should be normally high/active low signals coming from the core at your REU interface. The verilog code example was for a real cart to be plugged into a real c64. Keep the updates coming, it's really intere...
by dentnz
Thu Feb 18, 2021 11:45 pm
Forum: Commodore 16, 64, 128, VIC-20, PET
Topic: A matter of Bits and Cartridges.
Replies: 27
Views: 12771

Re: A matter of Bits and Cartridges.

So executing the DMA transfer is at least happening. However, I am not seeing the correct data going into the REU (SDRAM). And certainly, attempting to transfer it back again results in nothing happening. It also looks like the state machine gets locked once the transfer is complete. unknown.png I am trying to get the DMA signal to come out of the ...
by dentnz
Tue Feb 16, 2021 10:44 am
Forum: Commodore 16, 64, 128, VIC-20, PET
Topic: A matter of Bits and Cartridges.
Replies: 27
Views: 12771

Re: A matter of Bits and Cartridges.

So good progress. I’ve got the registers working, including writing to the registers. This means that the REU tools detect that a REU is attached, since they usually write a set of numbers into Df02-df07 and check that those numbers can be read back. I’ve yet to test the execute bit, but will look at that shortly. I think the REU data should be mix...
by dentnz
Thu Feb 11, 2021 1:47 am
Forum: SNES (Super Nintendo Entertainment System)
Topic: MSU-1
Replies: 121
Views: 107347

Re: MSU-1

Yes, the looping audio is pretty tricky really, particularly when you have to take into account the fifo buffer. Say the loop point in the msu audio file puts the loop point *byte offset* some way into the file... The algorithm goes something like so: - Work out the SECTOR offset from the loop byte offset - Determine if the END of the audio file fa...
by dentnz
Thu Feb 04, 2021 10:20 pm
Forum: Commodore 16, 64, 128, VIC-20, PET
Topic: A matter of Bits and Cartridges.
Replies: 27
Views: 12771

Re: A matter of Bits and Cartridges.

Some one wrote this REU as well, which may be of some use for example code . . . https://github.com/zeldin/super-reu There is also this document : http://www.zimmers.net/anonftp/pub/cbm/documents/chipdata/CSG8726TechRefDoc-1.0.zip The SuperSnapshot cart is also compatible with the REU and both could be used at the same time, I don't know of any ot...
by dentnz
Wed Feb 03, 2021 10:09 pm
Forum: Commodore 16, 64, 128, VIC-20, PET
Topic: A matter of Bits and Cartridges.
Replies: 27
Views: 12771

Re: A matter of Bits and Cartridges.

So not much progress at this stage. I believe that the way forward is to add an additional cartridge type to the cartridge module. Then, when it's attached (either via a cart file, or OSD configuration), enable reu with a signal (setting exrom and game signals correctly). The sdram instantiation would then pick this signal up and start to deliver b...
by dentnz
Tue Feb 02, 2021 4:19 am
Forum: Commodore 16, 64, 128, VIC-20, PET
Topic: Super CPU Support?
Replies: 15
Views: 10462

Re: Super CPU Support?

Yes I thought I saw that the minimig core had been ported to the Chameleon. Hilarious. As I said, the REU is the first thing I want to try... It will give me an idea of how the DMA flag works. It should be possible to 'disable' the CPU in the c64 and hand over to another CPU running at a faster clock speed. Have to make sure I keep within the appro...
by dentnz
Mon Feb 01, 2021 9:00 pm
Forum: Commodore 16, 64, 128, VIC-20, PET
Topic: A matter of Bits and Cartridges.
Replies: 27
Views: 12771

Re: A matter of Bits and Cartridges.

Would you be interested in working on REU together? I’ve started to look at it from a cartridge perspective. The easy flash already has the ability for 1mb of paged rom, the REU is much the same, but it has DMA and a set of registers to help bank switching and copying data around between the REU and C64 RAM. Check out the SuperCPU post in this foru...
by dentnz
Mon Feb 01, 2021 4:48 am
Forum: SNES (Super Nintendo Entertainment System)
Topic: MSU-1
Replies: 121
Views: 107347

Re: MSU-1

https://www.youtube.com/watch?v=DfY3afu2rzc Audio sounds like it is working well... Better in fact, since opening the OSD does not cause the audio to stutter. I think these are changes that were added to the OSD as part of the MegaCD and PCE CD cores. Video is NOT working however. I have a feeling that I am not looking at the last code changes. I m...
by dentnz
Mon Feb 01, 2021 4:39 am
Forum: Commodore 16, 64, 128, VIC-20, PET
Topic: Super CPU Support?
Replies: 15
Views: 10462

Re: Super CPU Support?

I've decided to take a look at the ram expansion unit as suggested by Sorgleig. If I have an understanding of how the cartridge slot works, I think I will be in a much better position to work on acceleration of the CPU. I have effectively added a new cartridge ID to the existing core and started to look at implementing geosRam first based on a copy...
by dentnz
Fri Jan 22, 2021 4:29 am
Forum: SNES (Super Nintendo Entertainment System)
Topic: MSU-1
Replies: 121
Views: 107347

Re: MSU-1

I've manually merged a reasonably new set of MSU-1 code into the latest master code. It compiled, but am yet to test. I'd like to tidy it up and maybe see if I can get the audio side of it into the main branch.
by dentnz
Thu Jan 21, 2021 10:32 pm
Forum: Commodore 16, 64, 128, VIC-20, PET
Topic: Super CPU Support?
Replies: 15
Views: 10462

Re: Super CPU Support?

Overclocking the CPU is entirely possible, however the SuperCPU has some additional advantages relating to RAM and being able to address more of it as a 16bit CPU. That said, overclocking the existing CPU is the first thing I looked at: I attempted to update the T65 CPU to be 20mhz, but the way the arbitration works is awkward: fpga64_sid_iec.vhd: ...
by dentnz
Thu Jan 21, 2021 7:15 am
Forum: Commodore 16, 64, 128, VIC-20, PET
Topic: Super CPU Support?
Replies: 15
Views: 10462

Re: Super CPU Support?

Seems that the T65 implementation (the CPU of the current c64 core) is actually capable of being a 65C816. Need to generate a new clock pulse for the 20 Mhz somehow (the PLL already has 3 setup and could potentially clock divide the 1mhz into 20), but it might be possible to change the mode of the CPU to be the 65C816 and get somewhere near the Sup...
by dentnz
Thu Jan 21, 2021 6:11 am
Forum: Commodore 16, 64, 128, VIC-20, PET
Topic: Super CPU Support?
Replies: 15
Views: 10462

Re: Super CPU Support?

Should be noted that the CPU that get's used in the SuperCPU is the 65C816... which happens to be already implemented in the SNES MiSTer core ;) https://github.com/MiSTer-devel/SNES_MiSTer/tree/master/rtl/65C816 More information here: http://mclauchlan.site.net.au/scott/C=Hacking/C-Hacking12/cmdcpu.html Things of note: - WDC W65C816S 16 bit micropr...
by dentnz
Thu Jan 14, 2021 10:36 pm
Forum: SNES (Super Nintendo Entertainment System)
Topic: MSU-1
Replies: 121
Views: 107347

Re: MSU-1

MSU-1 won't happen on the official normal SNES core unless someone forks the SNES core and rips out all the addon chips and makes a SNES-MSU-1 separate core. The core is using 90% of the FPGA's space basically as is, without MSU-1. It's the second largest behind ao486. Not necessarily. It's entirely possible that a smaller FIFO buffer could be use...
by dentnz
Sun Sep 13, 2020 11:20 pm
Forum: Commodore 16, 64, 128, VIC-20, PET
Topic: Anyone working on the 1750 (-ish) REU?
Replies: 4
Views: 3838

Re: Anyone working on the 1750 (-ish) REU?

The issue will be around how the RAM itself will be implemented. If we had enough FPGA space, then it would be pretty straight forward. The obvious alternative is to use the SDRAM instead, but the complexity is a bit higher and I am not sure about the latency of reads and writes.
by dentnz
Sun Sep 13, 2020 11:14 pm
Forum: X68000, PC88, PC98
Topic: X68000 Beta - Updates and Releases
Replies: 520
Views: 311854

Re: X68000 Beta - Updates and Releases

Ah, done!