VOGONS

Search

Common searches

Roland MPU-401 working partially only - what could be the reason?

Topic actions

First post, by cricket

Posted on 
User metadata
Rank Newbie
Rank
Newbie

Hi,

I recently got myself another MPU-401 which I connect to my Epson PC AX3 (Equity 386/20) via Lotech MIF-IPC-B Rev.2.
The MPU-401 feeds an MT-32 old.
With the external unit, that I already owned before, everything mentioned below is working perfectly fine.
The new unit works with Larry Suite Larry 3 in intelligent mode and Monkey Island.
However, Windows 3.1 does not detect the unit with any settings for port and IRQ.
Also Sim City 2000 and Lethal Weapon are not able to detect the MPU.
I can use MPUTHRU.COM on the unit and it prints ROM version 1.7C.

I opened up both units. The older one has an ROM in it and the PCB part number ends with an A.
The newer unit has no ROM and the PCB part number ends with a B.
There is no obvious damage visible on the board.

Anyone a guess / experience what could be the issue?

Reply 1 of 2, by Jo22

Posted on 
User metadata
Rank l33t++
Rank
l33t++
cricket wrote:

I recently got myself another MPU-401 which I connect to my Epson PC AX3 (Equity 386/20) via Lotech MIF-IPC-B Rev.2.
[..]
However, Windows 3.1 does not detect the unit with any settings for port and IRQ.

Hi cricket, did you try it in both Standard/386 mode already ?
I vaguely remember the 386 mode had its own way of handling interrupts/DMA channels/etc.
Maybe 386 Enhanced Mode gets in the the way or needs some tweaks in System.ini.
(It also stores some stuff in System\Midimap.cfg.)

Anyway, good luck! 😀

Best regards,
Jo22

"Time, it seems, doesn't flow. For some it's fast, for some it's slow.
In what to one race is no time at all, another race can rise and fall..." - The Minstrel

//My video channel//

Reply 2 of 2, by cricket

Posted on 
User metadata
Rank Newbie
Rank
Newbie

Hi Jo,

thanks for your feedback.

The issue must be on the external MPU-401 device.

The board and components of it look nice but I'm now gonna change the caps and if this doesn't help each IC available one by one.

Go to top of page Go to top of page
Back to Sound
Close window
Close window