The NEW Build Your Own Arcade Controls
Software Support => GroovyMAME => Topic started by: Jimbo on June 27, 2020, 05:29:40 pm
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Initially I posted this in the monitors sub forum, but was recommended I post in this one by buttersoft, so here goes!
I am trying to get the latest collaborative GroovyArcade 2020.06 to work. I have a passively cooled HD 6450 1G DDR3 PCI-E HDMI/DVD-D/VGA card.
I have a Philips CM8833-II 15Khz monitor and a retroelektronics pro-gamer supergun that I use successfully for testing jamma arcade PCBs.
I initially connected the VGA port to an Ultimarc JPAC so that I could use the supergun to test the video output on the Philips monitor. This wasn't working, it was giving me squiggly lines (like bad h-sync) during the groovyarcade monitor tests, and the JPAC's sync-ok LED wasn't lighting. With both jumpers removed the JPAC is supposed to output composite sync I believe. However when I removed the jumpers, the sync-ok LED was lit, but still the monitor was showing squiggly lines like bad h-sync.
I have now hooked up the VGA cable coming from the HD 6450 card to my scope. During the groovyarcade boot up, when it does the monitor tests, I register only 48.1Khz on the h-sync pin, with 2us pulses. Seems to be negative sync too, each pulse down to -5v (shouldn't the pulses be unamplified/sub 1v?).
I guess this would explain why the JPAC wasn't able to find the sync in range?
I also briefly tried to measure the v-sync pin on the vga cable, but I couldn't get anything legible from the short time the test was running. It's hard when I don't have a monitor screen showing the test output. The scope was just showing the frequency massively jumping around, certainly nowhere near 60Hz.
Any ideas what's up? I'm assuming during the monitor tests, the VGA card should be outputting 15Khz, and I thought the 6450 was a supported card.
I have 2 of these cards, both do the same thing.
Thanks for any help.
James
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I don't know GroovyArcade, but seems you are not getting 15khz from your VGA card. I think that by removing the jumpers you stop the JPAC from limiting sync passthrough to 15khz, which is why the sync OK LED comes on.
VGA negative sync pulse to -5v is normal & should be OK for arcade monitors. You're thinking of TVs, which by standard take a lower sync voltage ~ 0.3v.
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I don't know GroovyArcade, but seems you are not getting 15khz from your VGA card. I think that by removing the jumpers you stop the JPAC from limiting sync passthrough to 15khz, which is why the sync OK LED comes on.
VGA negative sync pulse to -5v is normal & should be OK for arcade monitors. You're thinking of TVs, which by standard take a lower sync voltage ~ 0.3v.
Thanks. I realised that the RGB pulses are the ones that are sub 1v, which is why the JPAC amplifies them. My bad. :lol
However even without the JPAC at all, just probing the pins during GroovyArcade boot up/monitor testing, the card seems to be outputting h-sync at ~48Khz, and v-sync is seemingly going crazy. Shouldn't v-sync be a stable 60Hz-ish?
If this card is bad, it seems unlikely I have bought 2 of the same model with the same fault, so my thinking is this card in general cannot output 15Khz?
I don't know for sure what make is it as I can't see it labelled on the card. It's a passively cooled one. PN: 299-2E164-8108A SKU# 11190-02. An online search of those though hints at it being an AMD Sapphire Radeon - which I thought was known to be supported?
Cheers
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Collaborative GA arcade guy here ;)
Besides eletric signals and all the real big hardware stuff, I can shed some light of what happens, and when.
PC boots > 640x480@60, so 31kHz minimum, unless you've flashed you ATI with ATOM-15
Syslinux bootloader > 640x480@60, can't get less unless I patch syslinux (which would be a pain to test, and would be a problem with 31kHz+ monitors)
At the syslinux bootloader, you select what kind of monitor you own depending on its horizontal refresh rate. 15kHz is the very first line, so no need to bother with other cases most of the times.
Once you've selected 15/25/31 or LCD at boot, here comes the interesting part, as options are passed to the linux kernel to tell which resolution to use. So the kernel will siwtch the framebuffer to 15kHz in a very few seconds after it was loaded. From now on, the horizontal frequency won't change.
So it's normal you get some 31kHz+ video signal until the kernel is loaded.
Regarding polarities, it's all negative. The 15kHz resolutions that we've hardcoded in kernel use negative syncs, that's set in the stone.
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Hi Substring - thanks for your post. Maybe I'm doing something wrong, but the boot up process you've described is not what I see at all.
I've plugged in an LCD monitor in the DVI port so I can see what's happening. The JPAC/Supergun/CRT is plugged into the VGA port. I haven't flashed the ATI card with ATOM-15.
On booting via USB flash drive containing GroovyArcade 2020.06, first thing I see is a black screen with small menu in the middle. This only pops up for a second or so and defaults on the top item of "Arch Linux archiso x86_64 UEFI CD".
Then you can see linux boot (all the messages scrolling up the screen)
When this ends, the CRT shows a rolling picture like the sync is massively out:
https://drive.google.com/file/d/10QKAsp_vV6zEW7BPoMWIYh1VVyp3QE5x/view (https://drive.google.com/file/d/10QKAsp_vV6zEW7BPoMWIYh1VVyp3QE5x/view)
The LCD then shows a blue screen with "Lights on Test it! - Press Enter if you see this test." Follwed by another message almost immediately after saying "We'll now test all cards outputs one by one" etc.
CRT then goes blank, then shortly after the bad-sync rolling screen again.
Next screen on the LCD is showing me it's found an LCD in the DVI port and selected it. No mention of the CRT connected to VGA.
Throughout this process, I appear to be getting both sync-in and sync-ok LEDs lit on the JPAC. This is with no jumper, or with the jumper on 15Khz.
But when I probe the VGA port I've not seen 15Khz on there at any point of the boot process. :-/ :dizzy:
At no point do I get asked what kind of monitor I have etc. Which leads me to believe I've done something wrong?
Cheers
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Don't boot in UEFI, boot in legacy ;)
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Aaah!!! THANK YOU.
I did know about the UEFI, and I had already changed my bios to CSR/UEFI, not just UEFI as that's the only setting I could see.
Then after you posted I checked the boot order in advanced bios settings... and spotted the USB was set as first boot with UEFI. So I switched that to just USB boot... and it all works as expected.
Thanks again, sorry for wasting everyone's time. :-[
EDIT: For those interested, using a JPAC, I had to have the jumpers on both 15Khz and 31Khz to see anything. I'm assuming this is because the GA loading screen and frontend are 640x480 interlaced?
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Bios and syslinux are 31kHz, it's only when the kernel loads that we switch to 15kHz, depending on the user's selection at syslinux. The real GA splash screen is 15kHz.
The jpac jumpers configuration is to halve 31kHz resolutions to 15kHz. Usually I recommend people to make their i stall with both a LCD and their CRT (if possible), this doesn't interfere for GA's final configuration. The LCD helps for the early boot stages, and is useless once GA switches ti 15kHz
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Thanks - that makes sense.
Are the jumpers selected when they are open? If I place the jumper on the 15Khz pins on the JPAC, I get no stable video at all. Either during boot, or at attractmode, or when running a game. If I put the jumper on the 31Khz pins, I get the halved resolution during boot, then a flickering attractmode (looks interlaced), then mame games in 15Khz no problem.
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By default it's an interlaced resolution. You can switch to a progressive one in the gasetup menu.
A jumper option is valid when the jumper is on 2 pins. Having the 15k one set should only let 15kHz signals through. Mine is set with 15 +31, never tried without the 31k jumper
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basically there are three jumper positions = 15, 25 & 31. Jumper on appropriate position should only let that frequency through.
With two jumpers on both 15 & 31 is special. It still only lets only 15khz through - However, if it detects 31khz it will halve the frequency thus 31khz/2 = 15khz, giving you a viewable split-screen. The split-screen is pretty basic and is only for debugging purposes and also serves to protect the monitor from frequencies out-of-range, you wouldn't play games or run desktop in it. I think this is the default position for the JPAC, it is usually shipped like that
Quality of split-screen image varies considerably from one monitor to the next.
Other combos of two jumpers (that is, on 15/25 or 25/30) have no special effect that I know of, might not even work.
I don't know why your doesn't work with just the 15khz jumper on, but it isn't worth worrying about too much. Like Substring, I usually only ever run my JPACs with jumpers on 15/31 too.
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Thanks for the explanation gents.
As you say, with both jumpers it works no probs.
I'm having another issue now though where attractmode seemingly freezes randomly when I press a key/button to navigate the list of games. Sometimes it's fine, others it freezes and I have to reboot.
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Make sure power saving is disabled in AM prefs. Otherwise try disabling video snaps
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Thanks - Power saving is disabled. I've not yet figured out how to disable video snaps but I'll have more of a look tonight after work.
What I have noticed though is the video snaps are not looping, they're just freezing at (what I think is probably) the last frame of the video.
I read the other thread about the issue with interlaced mode as this seems to be an identical issue, but I'm running your 2020.04 version which looks like that was fixed. I'll try to figure out how to run attractmode in progressive tonight also.
Cheers
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Why not run 2020.06 ?
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Sorry. Typo. :) i am running 2020.06.
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Try deleting video snaps to see if you still have the problem.
another way could be to force a progressive resolution from gasetup
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Had a look again today.
I managed to bugger up something by going through the gasetup menus so that when I rebooted, the monitor output was garbled again. No 15Khz - no ga splash screen showing, only bad-sync squigglies. I couldn't do a thing so as it's fairly quick I reinstalled the whole thing again from usb drive.
I was curious to find out what/why this was and so tried a few things, and I've narrowed it down to the following. I've repeated a few times with the same result...
If I go into gasetup video options, and select video resolution, it shows me the list with 640x480iS selected as I expect. I didn't want to change anything at this point, so I clicked <skip>. Then cancelled back to the main menu.
If I do the above, when I reboot, the monitor has lost its sync and I can't see anything no matter what I do.
I would have thought entering that menu and pressing <skip> would do nothing, but seemingly it does something. Have I misunderstood the purpose, or found a bug or unwanted feature? All I can think is entering that menu resets the resolution to be used, and <skip> means it doesn't ever set it again. Should/could that be it? Should a cancel button also be on that screen?
I'm not complaining btw :) It just wasn't what I was expected as I didn't select / change anything in that menu.
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I wished I could say "It's not a bug, it"s a feature !". But it IS a bug, will fix it ! Thank you for reporting it !
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No worries. :)
After a bit more testing, setting the video resolution to 640x240 progressive doesn't stop the freezing in AM after it boots up.
However, after it freezes and I have to "end process", restarting AM from gasetup again, and it seems fine... no freezing (iirc this was the same when in interlaced). I've done this a few times now and it seems consistently fine after restarting AM from gasetup.
So maybe it's something on first boot that isn't initialised fully?