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trying to setup a MT-32 via a mpu-ipc-t card and breakout box

oblivion

oblivion

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Apache Junction, AZ
I know, I'm full of issues tonight. I'm trying to enhance my 486 but nothing has been working out smoothly.

I've been running my MT-32 on my 486 via a sb16 for years with few issues but recently got a hold of a Roland mpu-401-t midi card and breakout box. after hooking it all up though no luck. I've disabled the midi on my sb16 via the diagnose function. also the sb is set to irq 5 and the midi card to irq 2 so no conflict there. I've tested fate of atlantis and quest for glory and I do get sound but its completely incorrect like the wrong midi signal is being sent. the digital voice and sound effects from the sb16 are prefect but the mt-32 now just sounds like a jumble of random noises.

I also tried going back into the games setups and making sure the sound options were correctly done and they are.

the breakout box is an mpu-ipc and the card itself is an mpu-ipc-t does that make a difference?
 
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figured it out. looks like a speed issue. when I hit the turbo button to slow the machine down it seems to work ok for some games, for instance fate of atlantis sounds line but quest for glory (an older game) is still a jumble of sounds. I thought the mpu-ipc-t worked fine on a 486? is the MPU-401AT the only roland mt-32 card designed for a 486 and above?
 
I'll have to Google some more over at Quest Studios forums. I had thought that the MPU-IPC-T was good running in up to a ~200mhz Pentium, just like the LAPC-I
 
Maverick1978 said:
I'll have to Google some more over at Quest Studios forums. I had thought that the MPU-IPC-T was good running in up to a ~200mhz Pentium, just like the LAPC-I
Click to expand...

after more testing I dont think its a speed issue. I suspect its the breakout box. I thought they were all compatible with eatch other but it seems a mpu-ipc box will not work and I need a mpu-ipc-t specific box.
 
Comparing my MPU-IPC card to the pictures I can find of an MPU-IPC-T (actually, they're your pictures, over on Vogons), I do see a pinout difference on the connector... lemme try to trace it out, it may just be as simple as moving some pins around on the breakout box's connector.
 
Old Thrashbarg said:
Comparing my MPU-IPC card to the pictures I can find of an MPU-IPC-T (actually, they're your pictures, over on Vogons), I do see a pinout difference on the connector... lemme try to trace it out, it may just be as simple as moving some pins around on the breakout box's connector.
Click to expand...

its worth a try, thanks

honestly though its kind of a relief that its probably the box and not the card itself.
 
OK, short version: you need the proper IPC-T box.

Long version:
The pinout is almost the same, except that the IPC has pin 12 connected and it's NC on the IPC-T. After a few minutes of 'WTF' trying to figure out what was going on, I finally noticed that the IPC-T has a 74LS04 where mine has a 74LS08 (position IC12 on your card, though it's marked IC3 on mine). I already knew that the IPC has a 'SYNC' port that the IPC-T lacks, and that additional pin seems to be related to that function, but apparently there's a bit of a difference in the circuitry on the card (and probably also in the breakout box) to accompany that... it's not going to be as simple as leaving the relevant pin unconnected. That doesn't mean it's necessarily impossible to mod either the card or the existing box, but it'd take a schematic of the IPC-T box and a decent understanding of logic circuitry, both of which I lack. The better route would be just to get an IPC-T box, since one is available for a reasonable-ish price. (Though if you get it, maybe crack it open and get some pictures of the layout... I'm kinda curious how it's set up.)
 
Old Thrashbarg said:
OK, short version: you need the proper IPC-T box.

Long version:
The pinout is almost the same, except that the IPC has pin 12 connected and it's NC on the IPC-T. After a few minutes of 'WTF' trying to figure out what was going on, I finally noticed that the IPC-T has a 74LS04 where mine has a 74LS08 (position IC12 on your card, though it's marked IC3 on mine). I already knew that the IPC has a 'SYNC' port that the IPC-T lacks, and that additional pin seems to be related to that function, but apparently there's a bit of a difference in the circuitry on the card (and probably also in the breakout box) to accompany that... it's not going to be as simple as leaving the relevant pin unconnected. That doesn't mean it's necessarily impossible to mod either the card or the existing box, but it'd take a schematic of the IPC-T box and a decent understanding of logic circuitry, both of which I lack. The better route would be just to get an IPC-T box, since one is available for a reasonable-ish price. (Though if you get it, maybe crack it open and get some pictures of the layout... I'm kinda curious how it's set up.)
Click to expand...

I'll probably be snagging one this week then after I'm paid. I'll defiantly throw some pictures up and let you know. thanks for looking though.
 
mpu-ipc-t arrived today. hooked it up and it worked fine. heres the images I promised

f826.jpg


9usm.jpg


t3mt.jpg
 
Very nice. I always like to buy things myself as I do not have the training or motor skills to fix broken or modify / build electronics unfortunately. :(
 
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