OPL2LPT

Discussion about old sound cards, MIDI devices and sound related accessories.

Re: OPL2LPT

Postby dreamblaster » 2018-8-13 @ 17:49

TimWolf wrote: :exclamation: You rock!

I'm going to get one of these for my Tandy RLX HD. I'm not going to put the port on it. I'm going to mount it internally and pipe it through the Tandy sound board sharing the volume knob. Goal is to have a switch for the Tandy Sound / LPT port so that I can still use the printer and Tandy sound on one setting, and the Adlib on the other. "Think it'll work?" ~


Thanks !
Yes i think it will work.
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OPL2LPT, OPL3LPT, X2, S2, S2P, MCE2VGA, ... many projects ! Have a look, and thanks for your support !
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Re: OPL2LPT

Postby SteveC » 2018-8-13 @ 19:51

Well would you look at this https://youtu.be/adhjvT4SeyQ :) Thanks sayjionix
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Re: OPL2LPT

Postby sayjionix » 2018-8-13 @ 21:25

SteveC wrote:Well would you look at this https://youtu.be/adhjvT4SeyQ :) Thanks sayjionix


Nice! :-D I'm glad it helped also for your PS/2!

Cheers,
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Re: OPL2LPT

Postby Paralel » 2018-8-14 @ 00:10

To me, it sounds like it should be a revision to the board to include this resistor.
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Re: OPL2LPT

Postby 640K!enough » 2018-8-14 @ 00:27

Paralel wrote:To me, it sounds like it should be a revision to the board to include this resistor.

Agreed; at the very least, the design should be revised before another batch is ordered.
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Re: OPL2LPT

Postby dreamblaster » 2018-8-14 @ 05:45

640K!enough wrote:
Paralel wrote:To me, it sounds like it should be a revision to the board to include this resistor.

Agreed; at the very least, the design should be revised before another batch is ordered.

Yeah will do. I will also list the mod on my site, after some more testing.
I don't have a PS/2 system here, will pm sayjionix for some more tests.
Visit http://www.serdashop.com for retro sound cards, MIDI PCB's, and video converters
OPL2LPT, OPL3LPT, X2, S2, S2P, MCE2VGA, ... many projects ! Have a look, and thanks for your support !
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Re: OPL2LPT

Postby Scali » 2018-8-14 @ 07:16

sayjionix wrote:today I made some analyses to find out what causes the OPL2LPT to output only distorted screechy sounds on some of my computers / IO-controllers. I think I came to an idea and an option to fix it, but not sure if this is the preferred way, so please let me know what you think.


Interesting...
I found a similar problem on my IBM 5160 and PCjr... I wrote my own VGM replayer for OPL2LPT, and initially tested it on my 286-20 and Celeron 1.5 GHz laptop. The code worked fine on both.
Then I tested on the 5160 and PCjr, and found that they only played garbage.

The way I solved it was by changing the order of the commands sent to the LPT.
Apparently the IBM printer interfaces were sensitive to this somehow. The changed code still worked fine on the other two machines.

I can build some test programs using both variations. I wonder if the issue I had was similar, and changing the commands around would somehow change something in the signals similar to the resistor you added.
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Re: OPL2LPT

Postby sayjionix » 2018-8-14 @ 11:59

Scali wrote:I wonder if the issue I had was similar, and changing the commands around would somehow change something in the signals similar to the resistor you added.


That's interesting! As it can be seen on the comparison of the Adlipt TSR and the OPL2TEST program, a small timing difference of the command lines can have impact on the result (at least if the STROBE signal is not too washed out, as it is for example on my 486). So your command sequence may have provided enough time for STROBE to rise again, before RESET toggles. But that's just a guess...
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Re: OPL2LPT

Postby sayjionix » 2018-8-14 @ 14:27

@dreamblaster: got your pm and will do more tests tomorrow :) Unfortunately I can't pm you back right now, as new members on vogons apparently don't have rights for that. I already asked the admins if they can unlock me. If it's not working soon, I will contact you differently.
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Re: OPL2LPT

Postby dreamblaster » 2018-8-31 @ 21:04

OPL2LPT easy mod : 1k pullup on strobe signal, for solving compatibility issues on PCJr and possibly other early computers
only needed if you experience problems (I could not test on my PC, as it always works, also without the mod)
OPL2LPTMOD.JPG


If you have PCJr or similar, and this does not solve the problem, please report in this thread
Visit http://www.serdashop.com for retro sound cards, MIDI PCB's, and video converters
OPL2LPT, OPL3LPT, X2, S2, S2P, MCE2VGA, ... many projects ! Have a look, and thanks for your support !
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Re: OPL2LPT

Postby dr.zeissler » 2018-10-04 @ 10:13

I'll check out this little nice device soon. I have a FSC-C6-Desktop (D1026) with integreated Onboard-Sound.
I think I am able to deactivate the bad fm-synthesis and use this little device instead.
CPU: PII 133-333 MOBO: SNI-D981 RAM: 512- FDD: Dualfloppy 3,5"HD/5,25"HD - 3,5"HD - 5,25"DD ISA-Catweasel HDD: 2x40GB - DVD
ISA(3): Audician32-S2Dreamblaster - GusACE PCI(3): Monster3D- Intel NW AGP(1): 3dfx V3-3000
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