MAME Emulation

A place to discuss everything Dragon related that doesn't fall into the other categories.
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.mad.
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Re: MAME Emulation

Post by .mad. » Tue Apr 30, 2019 7:47 pm

Hi Pernod70,

i found a problem with CAS loading in MAME for a few games.
sorry i can't give you too much technical info.
but i guess it's some sort of tape protection that MAME can not read yet.

Underbeings of Croth.
this requires approx 10 seconds of silence (1075 bytes or more of [55]) before loading the data part.
adding the extra bytes fixes the CAS loading in Xroar.
but MAME seems to skip that 'gap' and go straight to the start of the data load.
this causes the game to stop loading with an error.
A WAVE file works at this point.

if you spilt the CAS file into two parts main+gap and DATA, and swap the CAS file after loading the main part.
it carries on loading and works.

A very similar problem with this game...
Return Of The Ring.
this stops at the loading screen as it checks and loads random data, it fails and resets the machine.
again if you split the CAS file at that data check point, and swap the files it works.
Attachments
Return Of The Ring [mame].zip
(45.36 KiB) Downloaded 6 times
Underbeings of Croth.zip
(153.82 KiB) Downloaded 6 times

Pernod70
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Re: MAME Emulation

Post by Pernod70 » Tue Apr 30, 2019 8:45 pm

.mad. wrote:
Tue Apr 30, 2019 7:47 pm
i found a problem with CAS loading in MAME for a few games.
Would this be due to not yet supporting the cue extension?

sixxie
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Re: MAME Emulation

Post by sixxie » Tue Apr 30, 2019 9:58 pm

Pernod70 wrote:
Tue Apr 30, 2019 8:45 pm
.mad. wrote:
Tue Apr 30, 2019 7:47 pm
i found a problem with CAS loading in MAME for a few games.
Would this be due to not yet supporting the cue extension?
Unlikely - even though XRoar now writes CUE data when rewriting, it always puts a run of leader bytes in to account for any silences if CUE weren't understood.

I've actually done this wrangling for Underbeings myself too just recently and can confirm that even if I just remove the CUE data from the end (so no special timing information available), XRoar can load it but MAME can't. A simple 'cas2wav' of that self same CAS file, and MAME is fine with it.

Edit: attached a zip with non-working CAS and working WAV generated from it. The CAS has no CUE data.

Is it possible MAME is actually interpreting the structure of the CAS file (and skipping "excess" leader) where it should just be feeding them to the emulation as a sequence of pulses/waves?
Attachments
underbeings.zip
(66.55 KiB) Downloaded 7 times

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robcfg
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Re: MAME Emulation

Post by robcfg » Wed May 01, 2019 9:29 pm

I posted a report on MameTesters about the NTSC artifacting on PAL Dragon machines, and got curious about it so I think I'm near having the PAL artifacting working.
MAME_PAL_Artifacting_Dragon_Comparison.jpg
MAME_PAL_Artifacting_Dragon_Comparison.jpg (93.6 KiB) Viewed 196 times
:mrgreen:

pser1
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Re: MAME Emulation

Post by pser1 » Thu May 02, 2019 2:12 pm

Hi Roberto Carlos,
that's really a great job what you are doing. The colours are very clean!
Looking forward to try the new MAME version that comes with this changes
Thanks a lot
cheers
pere

Pernod70
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Location: Croydon, UK

Re: MAME Emulation

Post by Pernod70 » Thu May 02, 2019 4:06 pm

robcfg wrote:
Wed May 01, 2019 9:29 pm
I posted a report on MameTesters about the NTSC artifacting on PAL Dragon machines, and got curious about it so I think I'm near having the PAL artifacting working.
From those screenshots I have no idea which is which, which is why I didn't want to get involved with the 6847. When you're done make a Pull Request and hopefully someone more familiar with it will get it merged.

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robcfg
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Re: MAME Emulation

Post by robcfg » Thu May 02, 2019 4:08 pm

The left one is with pal artifacting and the one on the right is without any artifacting.

As soon as I finish it, I’ll make that pull request.

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.mad.
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Re: MAME Emulation

Post by .mad. » Fri May 03, 2019 12:04 pm

on the subject of Artifacting... :mrgreen:

can you tell me if that status can be changed from the command-line in MAME.
VDG - OFF (0), Standard (1), Reversed (2).

i guess it will be something like this, if it exists...
-:vdg:artifacting 0

editing the cfg works.
<port tag=":vdg:artifacting" type="CONFIG" mask="3" defvalue="1" value="0" />
Attachments
mamemenu.PNG
mamemenu.PNG (13.27 KiB) Viewed 175 times

Pernod70
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Re: MAME Emulation

Post by Pernod70 » Fri May 03, 2019 12:09 pm

.mad. wrote:
Fri May 03, 2019 12:04 pm
can you tell me if that status can be changed from the command-line in MAME.
VDG - OFF (0), Standard (1), Reversed (2).
No, Configuration options cannot be selected from command-line.

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.mad.
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Re: MAME Emulation

Post by .mad. » Fri May 03, 2019 5:47 pm

Pernod70 wrote:
Fri May 03, 2019 12:09 pm
No, Configuration options cannot be selected from command-line.
can i please request it?. ;)

i would also like option to disconnect LEFT or RIGHT Joystick from the command line.
i have seen strange / disabled fire buttons, when both joysticks are enabled in a couple of games.
e.g. SHAFT
this ends up mapping RIGHT fire button on KEY 7.

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