Search found 884 matches
- Sun Jul 09, 2017 8:06 pm
- Forum: Controls
- Topic: Mega Mouse Usage
- Replies: 23
- Views: 36490
Re: Mega Mouse Usage
Thanks for this quick test. And yes, it's just a one shot write sequence , it's not supposed to update itself. Results are interesting but definitively not what is expected from games (and quite different from what you get in emulators). I suspect the reason is I'm switching TR output too fast for t...
- Sun Jul 09, 2017 12:36 pm
- Forum: Controls
- Topic: Mega Mouse Usage
- Replies: 23
- Views: 36490
Re: Mega Mouse Usage
Sorry to bump this thread but anyone here having a Sega/Mega Mouse could test this ROM on hardware (with mouse controller plugged in port 2) and report output values ? I'm trying to figure the acknowledge latency of the mouse protocol, as it seems to be (involuntarily ?) needed by a few game routines.
- Fri Jun 23, 2017 1:10 pm
- Forum: Hardware
- Topic: HDD (or flash) instead of a CD, questions...
- Replies: 140
- Views: 165577
Re: HDD (or flash) instead of a CD, questions...
It's not exactly the same (it push Q first, not P) but i think I got it know, based on previous post Beware that this last diagram is about different signals (SQCK/SQDT)- also present on CXD2500 chip (the latter is just named SQSO) - which are dedicated to Q-channel (with CRC verification): that wa...
- Tue Jun 20, 2017 12:08 pm
- Forum: Mega/SegaCD
- Topic: Subcodes only for CD+G ?
- Replies: 8
- Views: 12760
Re: Subcodes only for CD+G ?
If the SBSO line is flat, it won't bug the game ? It shouldn't affect software since, from my testing in emulator, neither games or BIOS care if the subcode interrupt never occurs But it's possible it could lock the ASIC and thus the whole Mega CD hardware, depending how it was designed. Quite unli...
- Mon Jun 19, 2017 9:17 pm
- Forum: Mega/SegaCD
- Topic: Subcodes only for CD+G ?
- Replies: 8
- Views: 12760
Re: Subcodes only for CD+G ?
D/M status, TOC and current Track infos are all retrieved/computed by dedicated 4-bit microprocessor using subcode Q data output by CD DSP on SUBQ pin (controlled by serial clock on SQCK pin). D/M status bit is found in Q subchannel control field while TOC and current Track infos are found in q-data...
- Mon Jun 19, 2017 7:43 pm
- Forum: Hardware
- Topic: HDD (or flash) instead of a CD, questions...
- Replies: 140
- Views: 165577
Re: HDD (or flash) instead of a CD, questions...
I wonder why they didn't do the same for the data : SDATA is sent what ever is D/M to the LC8951x Because that's the only way software can access sector data from the CD. This might not seem really useful for CD audio data but internal CD player for example uses it to display VU meter while playing...
- Tue May 02, 2017 12:50 pm
- Forum: Video Display Processor
- Topic: Titan's Mega Drive tech docs including Debug Register
- Replies: 36
- Views: 55519
Re: Titan's Mega Drive tech docs including Debug Register
Are you preserving the list of sprites determined to be on the current line when you do the re-fetch (sounds like maybe that's what you are doing, but it's not 100% clear)? Correct rendering relies on sprites showing on a line based on the old Y value even though the new Y value would cause them to...
- Sun Apr 30, 2017 7:55 am
- Forum: Video Display Processor
- Topic: Titan's Mega Drive tech docs including Debug Register
- Replies: 36
- Views: 55519
Re: Titan's Mega Drive tech docs including Debug Register
No idea what causes the vertical stripes in the 3rd pic, though, incorrectly emulated illegal plane modes maybe? BlastEm had these too and I believe fixing that is what got rid of them. Yes,that was it. Genesis Plus correctly emulated all illegal plane sizes except two ("10 10" and "10 11" in above...
- Sat Apr 29, 2017 12:07 pm
- Forum: Video Display Processor
- Topic: Titan's Mega Drive tech docs including Debug Register
- Replies: 36
- Views: 55519
Re: Titan's Mega Drive tech docs including Debug Register
Off course you are right, totally forgot about that. The textured cubes scene also look much less broken now...Kabuto wrote: This looks like you still need to invert address bit 0 after converting the target address for 128k mode emulation.
- Sat Apr 29, 2017 8:03 am
- Forum: Video Display Processor
- Topic: Titan's Mega Drive tech docs including Debug Register
- Replies: 36
- Views: 55519
Re: Titan's Mega Drive tech docs including Debug Register
1) no per column vscroll changes here, just per rasterline vscroll changes in the zoomer, no vscroll changes at all when it twists Strange. This is what I got, not sure where this comes from . overdrive-1.jpg Also got similar weird vertical jitter on those voronoi circles overdrive-8.jpg 4) we call...
- Tue Apr 25, 2017 8:28 am
- Forum: Video Display Processor
- Topic: Titan's Mega Drive tech docs including Debug Register
- Replies: 36
- Views: 55519
Re: Titan's Mega Drive tech docs including Debug Register
This sounds like you're not treating transparent sprite pixels correctly, this effect uses sprites with palette 3, so their transparent pixels will be written to the linebuffer as 0x30. Yes, this was indeed the case: as mentioned in my previous post, transparent sprite pixels were never rendered in...
- Mon Apr 24, 2017 12:06 pm
- Forum: Video Display Processor
- Topic: Titan's Mega Drive tech docs including Debug Register
- Replies: 36
- Views: 55519
Re: Titan's Mega Drive tech docs including Debug Register
From what I could tell, background color was set to color 0 so result would be the same. I think the background is never displayed anyway if bit 7 or bit 8 is set (or maybe only during x/y borders in case sprite layer is the one being forced active, I don't know, the doc is not 100% clear about that...
- Mon Apr 24, 2017 9:24 am
- Forum: Video Display Processor
- Topic: Titan's Mega Drive tech docs including Debug Register
- Replies: 36
- Views: 55519
Re: Titan's Mega Drive tech docs including Debug Register
Thanks again, I have another question regarding the debug mode when sprite plane is forced active (bits 8,7 = 0,1) : what happens for pixels where there hasn't been any sprite pixel (transparent or not) rendered in the line buffer ? The sprite buffer pixel color value is normally 0 in this case (sam...
- Sat Apr 22, 2017 8:14 am
- Forum: Video Display Processor
- Topic: Titan's Mega Drive tech docs including Debug Register
- Replies: 36
- Views: 55519
Re: Titan's Mega Drive tech docs including Debug Register
When bit 9 is set: 1) Make all four PSG channels always high (like when we use them for PCM) 2) Make their attenuation the same as for the channel selected by bits 11-10 That's all there's to it, really. You could do the PCM trick on them but 4x as loud (at the expense of no normal PSG output). Tha...
- Sat Apr 22, 2017 7:45 am
- Forum: Sound
- Topic: too many YM2612 infos ?
- Replies: 14
- Views: 20635
Re: too many YM2612 infos ?
Having a sub forum for YM2612 dedicated topics is a good idea but seems like a hard task to initialize and maintain. Each subthread should start with a post summarizing the current 'verified' informations we have on that part of the chip and kept updated according to the following thread discussion....