MPU-IMC on the MT-32 (issues with certain games)

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Re: MPU-IMC on the MT-32 (issues with certain games)

Postby vetz » 2014-8-25 @ 20:28

I won this auction:
http://www.ebay.com/itm/Roland-MPU-IMC- ... 7675.l2557

I'm planning on installing it into my IBM Server 320 with PCI & MCA and Dual Pentium CPUs.

My card has the extra daughterboard. I'll report back when I receive it :)
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Re: MPU-IMC on the MT-32 (issues with certain games)

Postby raymangold » 2014-8-29 @ 13:25

vetz wrote:I won this auction:
http://www.ebay.com/itm/Roland-MPU-IMC- ... 7675.l2557

I'm planning on installing it into my IBM Server 320 with PCI & MCA and Dual Pentium CPUs.

My card has the extra daughterboard. I'll report back when I receive it :)


Awesome, thanks so much.

I think I may do some tests on the model 80 later to see if this changes the behaviour of the MPU-IMC.

Ah right server320, PCI and MCA. I saw some before. Well depending on how that system behaves, you could add 3dfx cards, hmmm.
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Re: MPU-IMC on the MT-32 (issues with certain games)

Postby vetz » 2014-8-29 @ 13:42

It's an interesting setup indeed. No IDE ports, all integrated Adaptec SCSI and a 1MB Cirrus Logic VGA chip. With only 2 PCI slots I'm limited to what I can install. Since its so hard/expensive to find a MCA soundcard I need to go PCI. So that leaves just one PCI slot left to a better video card, which probably will have to be a Voodoo3 PCI if I want some Glide action while still keeping up good DOS/Windows performance. Some integrated audio/VGA PCI card could also be the solution. I'm going to buy an IBM Lan/A MCA Ethernet controller, so that is atleast covered :)
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Re: MPU-IMC on the MT-32 (issues with certain games)

Postby PeterLI » 2014-10-03 @ 18:59

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Re: MPU-IMC on the MT-32 (issues with certain games)

Postby raymangold » 2015-1-02 @ 02:51

I suppose I should provide an update, I got another one of the MPU-IMC cards with the extra PCBs for cheap-- I haven't noticed any differences between the two. Unfortunately to see what IC is there it requires to be desoldered, may do that later when I have time.

A more in depth test regarding the MPU-IMCs will be performed once I got the model 80 running properly with OS/2. The problem may be OS or CPU related (or even card related), but with the other computer the problem can be ruled out.
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Re: MPU-IMC on the MT-32 (issues with certain games)

Postby PeterLI » 2015-2-15 @ 21:36

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Re: MPU-IMC on the MT-32 (issues with certain games)

Postby pleonard » 2015-3-28 @ 22:02

So I just tried Gods with one of the MPU-IMC's that have been coming out of South Korea on eBay. These are in sealed boxes and, at least for the one I received, have the extra PCB. Computer is a PS/2 Ultimedia M57slc with, as the name implies, a 386 SLC chip.

The verdict? Works fine, except for a "Buffer Overflow" error during initialization. (Mine is a Rev0 MT-32). Sounds just fine.

Image

The MPU-IMC was set to its default IRQ of 9. The PS/2 57 has on-board SCSI and the same requirements for a reference partition as many of its IBM contemporaries, but so far no conflicts. (Anyone know the IRQ of the motherboard SCSI controller? It's not shown in the Reference Utility anywhere.)

Coincidently, I also have a CT5330 SoundBlaster MCV Pro in this system, which is at IRQ 7. That card works fine as well with GODS in my setup.
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Re: MPU-IMC on the MT-32 (issues with certain games)

Postby raymangold » 2015-3-29 @ 03:13

Hmmm that's very interesting. Well it must be a specific problem with the newer hardware or the P60 complex itself in the PS/2 Model 95. I'll give it a shot on my Model 80 whenever I get around to it.
Do you actually own an *utimedia* branded PS/2 57? If so I'd love to see a picture of the multicolor badge-- only if you have a moment of course.

The CT5330 and CT5320 don't work well on the PS/2 Model 95 due to the low-speed schottkeys used, only the FM functions properly. I've tried both and had the same MicroChannel bus timeout issues. However I recently purchased a ChipChat 16, so I'm betting it won't get the timeout problems like the creative cards (no I'm not a hoarder with three MCA sound cards, I use them and do tests).

Oh you know what? I did see low speed schottkeys on the MPU-IMC. I disregarded them at first since (most) games worked in lieu of that, but I wonder if it too needs ALS ones for certain games. Hmmm...

At least we know the problem is potentially the PS/2 Model 95 which helps isolate a lot of variables now. When there's a rainy day and I have nothing to do, I'll document all of the schottkey chips on the CT5320 and MPU-IMC, and source some ALS equivalent replacements. The CT5330 uses *surface mount* ICs which I am not going to bother with since my equipment primarily deals with through-hole. So yeah, we'll see what happens after I get some ALS chips in the two cards. Of course a PS/2 running faster pentium CPUs will run into 'strange' problems on older MCA cards.

Note: the CT5320 actually was buggy on the game port even on PS/2s with slower procs due to the use of LS instead of ALS... so these schottkeys are definitely a problem in certain situations for PS/2s.
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Re: MPU-IMC on the MT-32 (issues with certain games)

Postby pleonard » 2015-3-29 @ 03:21

Hah, that badge was the first thing I took a picture of when I got the machine! :)

Image

I'm currently working on getting an authentic, period-appropriate IBM SCSI CD-ROM drive working. The best choice would be the cartridge-based 2x model -- they are original to the Ultimedias and have a blue eject button and blue volume dial. But almost all have dozens of SMD capacitors that have leaked.

Second-best would be the 4x tray-based models. They at least have a blue eject button...
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Re: MPU-IMC on the MT-32 (issues with certain games)

Postby raymangold » 2015-3-29 @ 05:02

pleonard wrote:Hah, that badge was the first thing I took a picture of when I got the machine! :)

I'm currently working on getting an authentic, period-appropriate IBM SCSI CD-ROM drive working. The best choice would be the cartridge-based 2x model -- they are original to the Ultimedias and have a blue eject button and blue volume dial. But almost all have dozens of SMD capacitors that have leaked.

Second-best would be the 4x tray-based models. They at least have a blue eject button...


I'd suggest one of the matsushita SCSIs-- the one I have in my Model 95 runs at 2x, however, it is able to read burned discs despite that (not all CD-ROM drives can read burned discs, it's especially rare to find slow speed ones that do). One advantage of slower speed CD-ROM drives is that they can read a disc almost instantly without having to spin up and are dead silent.

Here's one that's similar to the one I have with the same 'CR-503-B' model, but it looks externally slightly different:
http://www.ebay.com/itm/Genuine-IBM-CR-503-B-SCSI-CD-R-Optical-Drive-P-N-88G4899-88G4898-/151607108285?pt=LH_DefaultDomain_0&hash=item234c7ce2bd

(It has an IBM lavender button, but not the 'PS/2 Blue' style which I imagine you're after).

Replacing the SMT capacitors on the PS/2 drives isn't too difficult, just annoying. I've replaced them on some PS/2 FDDs (and voodoo 5500s). I find the easiest way is to gently rip them off and solder through holes in their place with bent leads; yes that's the 'forbidden' method, however every time I've tried to properly remove them I've found the solder is so stale that the heat ends up damaging the pad... yet ripping the capacitors off doesn't, go figure.
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Re: MPU-IMC on the MT-32 (issues with certain games)

Postby ZenoDiac » 2018-8-30 @ 19:51

raymangold wrote:So I finally got around to booting with diskettes and no SCSI or SCSI controller...

However, it appears GODS is coded to detect if it's being ran on A:\ and will then will refuse with: "attempt to run from non-original disk". I went ahead and edited the GODS DOS executable with a hex editor, but then it complains that there's an error with the INI config file (when there really isn't). So then it'll reinstall itself and add that line back into the executable, and the cycle repeats.

I suppose I can try contacting bitmap brothers' support, but I highly doubt I'll get a response.

Tried a few more games like master of magic, simon the sorcerer, space quest 4, they all worked fine. Master of Magic in particular was nice as you could specify every single variable. I think GODS is hard-coded to a weird address which means Kyrandia is as well. I suppose I could research some more decompilers and hex editors to see if I could just modify the game and force it to talk to IRQ 5 / 330.

EDIT:

After reviewing the PS/2 'planar' itself, it has ALS schottky chips on it too. So all MCA cards realistically should have the LS ones replace with ALS. Still waiting for the freaking hakko to arrive so I can begin this experiment...

---

So here are the current pending plans of action:
#1 see about getting that undocumented / odd MPU-IMC (I think I might just so I can do research on it, seeing as there's nothing on the internet about it).
#2 the schottky mod

I can also do other tests on the much slower Model 56. Personally, I am unconvinced I will be able to pull it off; the problem games may be hard-coded to address the PS/2 platform simply can't deal with.


Haha wow, sorry to have awoken the necrothread. I ran into the exact same error as you "attempt to run from non-original disk" with GODS when mounting on A:
Thanks for pointing out it's the directory itselfm otherwise it would've taken me ages to figure out.
A simple mount on C: drive and a copy-paste of the 2.5mb game files solved the issues!
Played this game back in 2002 lol and it still has my saved files! Very impressed I get to relive it now! Thanks.
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