VOGONS


First post, by PhilsComputerLab

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Ok so I found references online that state that on a CMS upgraded Sound Blaster you need to remove the OPL2 chip in order for CMS Music to play on version 1.0 of Prince of Persia by typing PRINCE GBLAST.

On a SB 2.0 the OPL2 chip is socketed, but that card needs a -5V PSU which I'd like to avoid.

So I de-soldered the OPL2 chip on one of my SB 1.5 cards:

IfvtoR6l.jpg

Soldered a socket:

uAUZ01Hl.jpg

UpIax23l.jpg

Wv3tINgl.jpg

And, with the OPL2 removed, tested Prince of Persia. But it sounded really off. Tried Monkey Island and Last Crusade in Game Blaster mode and it sounded as expected.

So I pulled out the only -5V capable PSU and tried it with the SB 2.0. The OPL2 was quickly removed and it sounded exactly the same, bad, way as on the 1.5 with OPL2 removed.

So is this a myth? Am I missing some CMS driver? Has anyone gotten this to work at some point?

I've attached a recording. It starts with Monkey Island and then Prince of Persia, both in Game Blaster mode.

The PC is a 386SX 33 MHz with 4 MB Ram and MS-DOS 6.22

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Reply 3 of 71, by PhilsComputerLab

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bjt wrote:

Having listened to it I wouldn't be surprised if that's normal. The POP title music is pretty discordant on MT-32 too.

Well it sounds proper in DOSBox and I believe Cloudschatze made some recordings somewhere.

Also I don't recall any distortions on the MT-32.

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Reply 4 of 71, by MobyGamer

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I was going to offer to put one of my real CMS boards into a system and record Secret of Monkey Island for you, but before doing so, I decided to test with my regular SB 1.5. It sounds perfectly fine, so I think the problem you're experiencing is unfortunately on your end, and not with the game's CMS support. As to what could be causing what you're hearing, I don't know, but it is obviously a timing problem. Maybe remove all of your cards except for vga/hard drive/sb and try again?

I've attached a recording. System was a Dell 316SX (386sx-16) running PC DOS 2000 and QEMM as a memory manager. I can make the 16/96 FLAC available if anyone wants it for research purposes.

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Reply 6 of 71, by PhilsComputerLab

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Interesting. I will try it with another motherboard. Didn't get around to doing this yesterday. Because the 1.5 AND the 2.0 are behaving the same way maybe there is some timing issue. It does indeed sound as if the timing is off. I tried a few things such as slower timings and without turbo button but it made no difference.

Monkey Island and Last Crusade work perfectly. It's only Prince of Persia for some reason. So no need for a recording on these games.

ibmg is likely that IBM music feature card.

@ MobyGamer

That recording is of Monkey Island, which works fine. Can you please test Prince of Persia?

@ MobyGamer how did you remove the OPL2?

EDIT: Tried another motherboard and getting the exact same issue. Also tried Star Control which with /s:cms but it plays music through the PC speaker...

I booted with F5, nothing loaded if that helps.

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Reply 7 of 71, by idspispopd

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ibmg should be IBM PS/1 Audio card:
IBM PS/1 Audio Card.
http://queststudios.com/smf/index.php/topic,2 … 4.html#msg22194

Agrees with Mobygames since POP should support PS/1 Audio card but not MFC.

Reply 8 of 71, by Great Hierophant

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ibmg is definitely IBM PS/1 Audio Game Card support. Installing any card with an Adlib chip will override all other sound selections except Sound Blaster. Any way to fix this?

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Reply 9 of 71, by carlostex

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The game probably has routines to detect a real CMS/Gameblaster card maybe it needs that CT-1302 chip which should be some sort of DAC. Probably the game wasn't made at all to use the CMS chips on a SB card. So if the game sees a SB based DAC it will always be a Sound Blaster and it will try to use the OPL2 chip.

I'm just speculating though

EDIT: Has anyone tried besides removing OPL2 also removing its DAC? More specifically the YM3014 small chip, labeled FM1314 in SB cards.

Reply 10 of 71, by keropi

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IIRC my CT1320 has all the yamaha chips socketed , I can give it a spin tomorrow and see what happens

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Reply 11 of 71, by MobyGamer

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Great Hierophant wrote:

Installing any card with an Adlib chip will override all other sound selections except Sound Blaster. Any way to fix this?

I can look into patching POP 1.0 to effectively skip over the adlib detection so that the other flags are honored. I'll tinker with it over the next few hours, and if I'm unsuccessful, I'll just put my CMS card into the 386 and test PoP for Phil.

Reply 12 of 71, by ripsaw8080

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In the 1.0 version of PRINCE.EXE at offset 13875h change 75h to EBh -- this will disable the OPL detection and the game will use the command line parameter for sound. I tried it in DOSBox with sbtype=sb1, and running the game with "prince gblast" produces GameBlaster music.

Reply 13 of 71, by carlostex

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ripsaw8080 wrote:

In the 1.0 version of PRINCE.EXE at offset 13875h change 75h to EBh -- this will disable the OPL detection and the game will use the command line parameter for sound. I tried it in DOSBox with sbtype=sb1, and running the game with "prince gblast" produces GameBlaster music.

Dude you're amazing!

Reply 14 of 71, by keropi

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^ no , not amazing... LEGENDARY is the correct word here.

@ripsaw8080

any chance this patch can be made for v1.3 of the game?
tbh I don't know what the differences are between 1.0-1.1-1.3 , I assume bug fixes? 😕

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Reply 15 of 71, by ripsaw8080

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Well, the hack isn't ideal. You get PC speaker sound effects when using CMS music, so an SB with CMS chips installed is still not fully supported. A better hack could allow SB sound effects along with CMS music, but dunno how complicated that would be.

keropi wrote:

any chance this patch can be made for v1.3 of the game?

The 1.3 version I have uses a setup program that doesn't offer GameBlaster as an option. It's possible to add the option in the setup program by modifying SETUP.CFG, which is a text file, but the game crashes if you select GB for music, so apparently there's no support for it.

Reply 16 of 71, by keropi

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ah yes... forgot about the setup... the good thing is that you can choose different devices for music and sfx...
still a usable CMS v1.0 PoP is nice! 😀

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Reply 17 of 71, by PhilsComputerLab

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ripsaw8080 wrote:

In the 1.0 version of PRINCE.EXE at offset 13875h change 75h to EBh -- this will disable the OPL detection and the game will use the command line parameter for sound. I tried it in DOSBox with sbtype=sb1, and running the game with "prince gblast" produces GameBlaster music.

Could you please explain this in more detail? I guess posting the executable is a no go. This is with something called a HEX editor? What editor would you recommend?

keropi wrote:

IIRC my CT1320 has all the yamaha chips socketed , I can give it a spin tomorrow and see what happens

Hmm so there seem to be different versions of that card, with socketed OPL2 and soldered one.

It would awesome if you could test this!

Last edited by PhilsComputerLab on 2014-10-22, 20:35. Edited 1 time in total.

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Reply 18 of 71, by keropi

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^ yeah it's a hex editor deal Phil.
I use ultraedit in windows and PSEDIT in DOS. Just select the "GOTO" option in the menu and type 0x13875 , it should transfer you to that exact place which will have a value of "75". You change it to "EB" and you save the new .EXE .
Done!

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Reply 19 of 71, by PhilsComputerLab

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Ok so it turns out that my second SB 1.5 has socketed chips. I made an image of both cards, there are subtle differences:

The top card is the one I modded with de-soldering the chip and soldering in a socket. The bottom card in untouched.

http://i.imgur.com/10c36nw.jpg

BUT with removed OPL2 Prince of Persia still sounds wrong. So at this point I'm very sceptical because I have tried 3 cards and in 3 different motherboards so far. So if someone else could test their 1.5 or 2.0 with OPL2 removed and running PRINCE.EXE GBLAST and let me know if it sounds like my recording above (fast forward past the Monkey Island bit).

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