PB 1400cs Serial / MIDI Problem

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So far, I have done incredible things to get this laptop running wonderfully, for very little money. This mystery box I bought from a school teacher with: maximum RAM, G3 215 mHZ, heaps of accesories. I have added a TFT screen, new PRAM, internal ethernet. It runs way faster than I expected, hard for me to believe it's a 33 mHZ NuBus machine - it runs circles around my 8100 G3 220!

When I bought this thing, I assumed it'd be useless for audio, but would make a nice portable MIDI sequencer (main reason why I got it). To my surprise, the audio is not bad! Although sound input needs a preamp to not sound noisy.

The killer is that I bought a cheep serial MIDI interface for the 1400 (Opcode ProfessionalPlus). At first it did not work, so I removed the interfaces ICs, socketed everything, touched up solder joints, replaced ICs. Same deal... I was horrified that when I got my 8600 runnng again, it sees and uses the MIDI interface with no problems. Using all of the same cables. So this seems to indicate that the logic board serial is -fuct-. I guess I should have devised a way to test the port before I did everything else, but I've never had this problem before. It hurts, since I put so much effort and bits of my nonexistant cash into this specifically for MIDI. I am running OS 8.6, and have tried both OMS and MidiShare - I know MIDI setup by heart, if the port worked I would have gotten things running straight away.

Any info on what serial chips the 1400 series uses? Simple info for a popular laptop, but my searches haven't yielded anything. If it's an off-the-shelf setup of surface-mounted ICs and such, then I'll try to score some and fix it, otherwise I guess I'll need a new board.

Alternately, I know there are joystick PCMCIA cards with MIDI capability, but I have only ever heard of drivers for windoze. Info on these or any other possible ways to install a functional MIDI port on a 1400 would be much appreciated!
Metrophage

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Good news and bad news… G

Good news and bad news…

Good news is that my serial port appears to NOT be fried, I was able to get it to work with something else.

Bad news is that I have been trying everything I can think of for two full hairpulling days of futility, and still no idea what the problem is.

Here's the deal. My PB 1400 has one serial port. I connect a simple no-frills MIDI interface (Opcode Professional Plus) to it via working serial cable, and no software recognizes it. If anyone has experience with MIDI on a PowerMac tower, etc you know that this is never an issue, the ports work without problems.

I connected the same MIDI interface to two other computers and it worked perfectly, right away. Then I tried connecting a deluxe, studio rack MIDI interface (Opcode Studio 4) to my PB 1400, and OMS Setup saw it right away! It works fine. So OMS can see my studio MIDI, but not simple, portable ones. This bites because my Studio 4 stays in its' rack, the idea is to use the pocket-sized portable with my laptop for field use.

The performace of the serial port itself is not bad, when I can connect it. The Studio 4 was running at the 1 mHZ setting with no problems. I connect the Pro+ and OMS can't even see that it is there. I can force OMS to load a driver for "Std. MIDI Device", but it doesn't seem to access the port, so it doesn't do anything.

Next I tried Grame's "MidiShare" drivers, since I've got some academic music software which can use its' drivers instead of OMS (in theory). No dice. Loading MSserial does not access the serial port as it does on my other machines. For good measure tried other MS drivers with similar results.

So - I know that the problem is not:
My MIDI interfaces…
My cables…
OMS…
This leaves my PowerBook / MacOS to wrangle with. I am truly perplexed, this is not working anything like my years of configuring mac MIDI on non-PowerBook machines. I have found posts like this one on forums over the past ten years, describing the same issue, unanswered. I expect that somebody out there has succeeded in using the 1400 series for MIDI, I am going to figure out how it can be done.

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How is this a hack?

This is, hopefully, leading directly to some new hardware. I use most of my macs for MIDI - juggling the same MIDI interface between them, which is not the most productive way to go about things. Serial MIDI interfaces are easy to build: 8-pin mini-din connect to an optoisolator. A few buffers, diodes, and resistors keep things from getting fried. I intend to make built-in MIDI interfaces for my machines which can run off of the disk drive power, and fit in a bay wired with internal serial cable. This reduces one wall-wart for each computer, and minimizes lost or damaged cables, while saving space.

Even the 1400 can have an interface built in. Either on the back panel, in a "book-end", or in an emptied floppy expander. Needless to say, I am not about to start making the hardware if I cannot figure out how my 1400 can run a practically identical device.

DanR's picture
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Specifications: 8100: Two

Specifications:

8100:
Two RS-232/RS-422 LocalTalk/GeoPort serial ports; mini DIN9 connectors (backward compatible with mini DIN-8 connectors)

8600:
Two RS-232/RS-422 serial ports compatible with LocalTalk and GeoPort cables; mini DIN-8 connectors

PB 1400:
Serial port for printers, modems, LocalTalk network, or other serial devices (RS-422)

-------

RS-232 is single-ended, RS-422 is differential... so completely different (site: http://www.rs485.com/rs485spec.html ). A quick search turns up adapter/converters... although they seem a little pricey.

How that works out, exactly, with your MIDI stuff I have no idea. :?

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Thanks for that link, DanR! J

Thanks for that link, DanR! Just the sort of stuff I need to study now!

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I think I know what was going

I think I know what was going on. Studying up on RS-422, the Mac MIDI interfaces I had to examine were beginning to make more sense. Also, I spoke with some former Opcode people who confirmed for me.

Main issue with the Professional Plus interface is the lack of any balanced line driver / receiver chips. It is assumed that the signals and clock will be strong enough for a Mac serial port... they might be for anything besides a laptop. When a Mac uses OMS drivers (or most any other), it defers to a clock signal from an external device so it can function at 1 MHZ and divide down to 32k from there. Without connecting to such a clock, OMS assumes that there is no interface present.

So this turns into a hack after all! I will either scrounge together some money for a few data transmission ICs, or see if I have any in some broken digital audio equipment in the garage. The circuit board in the Pro+ is perfect size for installing in a floppy bay, and the nice aluminum case will house the new MIDI interface circuit nicely.

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PB 1400cs Serial / MIDI Problem

Were you ever able to solve the problem using the existing interface. I'm trying to get a Opcode Translator Pro working with a powerbook 520.

(The Interface works fine with G3 Wallstreet and Mac Classic)

and the 520 port works with a printer..........

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No, not with the Pro+, it nev

No, not with the Pro+, it never worked on the 1400. I have read reports of Translators working fine, but I'd given mine away a while ago. I haven't built the circuit I mentioned yet, either! My electronics workbench is in the garage, and it has been the cold winter months here. Soon!

The deal is that the desktops and towers have very strong signals, so the interfaces don't need to be to proper spec, as such. Since the laptops are lower power ports, it can be an issue - real transmitter and reciever chips need to be used. My Studio4 interface works perfectly on my 1400. The portable units were usually a bit cut-rate though, so I'm building one.

CJ

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Duo 280c: same problems

I'm adding my contribute to this old thread by warning about the PowerBook Duo 280c's serial port: with MIDI interfaces, it gives the same problems described here. The port works flawlessly with a LaserWriter 4/600 PS instead.

I'd need to use it with MIDI because I want to run Galaxy Galaxy Plus Editors on it, since using this tiny PB is more sensible than having an old desktop Mac active just for that (Galaxy officially supports up to Mac OS 8.1).

Using a tested working cable, I connected to the Duo alternatively an Opcode Translator II and an Altech MIDIface LX (both positively tested on a Classic Colour) without success. I tried the Duo's modem/printer port (there is only one), and the modem port and the printer port on a Duo MiniDock, with no avail.

By the way, my 280c's motherboard has been upgraded to PowerPC 603e/100MHz.

Question: is an «upgrade» of a dumb standard MIDI interface possible, so that it becomes compatible with these reluctant PowerBooks? Is any blueprint or scheme available anywhere? Thanks (anyway:-)

Roberto Giannotta
Trieste, Italy

DrBunsen's picture
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You might have to make absolu

You might have to make absolutely sure nothing else is using the serial port. As the Powerbooks combine two "virtual" ports into one physical port, you have to make sure that the Chooser, Appletalk, and anything else on the system is either unloaded or pointed somewhere else. I can't remember how I did this right now, I remember it took a fair bit of funking around.

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More details? :-)

Uhm... I assume you were successful at using a MIDI interface with a similar machine: could you be more specific (which PB, which interface, wich OS - I'm using 7.6.1 but tried also with 8.1 - etc)?

Thanks Smile

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Duo 280 with 7.5.5 from memor

Duo 280 with 7.5.5 from memory, running MIDIgraphy through OMS. The actual synth was a bit screwy, so I gave up, but I did get a MIDI signal out of the Mac.

Create a stripped-down extensions set with only the extns and cps you'll need for MIDI.

Other things I remember: you need to set PPP or the Modem control panel to use the internal modem, Appletalk to use Ethernet or something, anything else that uses the serial port (Chooser?) needs to be redirected and/or disabled at startup with the Extensions Manager. Some of these will need to be set correctly once while loaded, then reboot to your "MIDI" extensions set.

And because of a bug with the serial ports, you need to delete some prefs file and reboot. Easiest way to do that is to find and download either reset-serial-port-2.1.sit.hqx or serialsetter-1.0.sit.hqx., nustuff them and have an alias for one or other of them in your "Shutdown Items" folder.

Here are some links which might be useful:

http://developer.apple.com/technotes/dv/pdf/dv_21.pdf
http://www.ibiblio.org/emusic-l/info-docs-FAQs/pb1xx.html
http://www.mug.jhmi.edu/mirrors/InfoAlley/0695/12/powerbook.html

The second one mentions this:

pb1xx.html wrote:

MIDI Mangler 1.1

Eliminate conflicts between the MIDI manager and the Chooser. Also, you can reset the status of either serial port.

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More details

I also dug up this old file from my archives.

Quote:

Date: Tue, 13 Jan 1998 22:39:42 +0100
From: name removed
Subject: [macwiz] Summary - Modem port/Printer port in PB Duo 210

I have received two answers from the list, one of them worked.

Original question: PowerBook Duo 210 has a combined modem port/printer port in the left "leg". If one uses a MiniDock one has a separate modem port and a printer port. I have for several years been using the the PB 210 with a MiniDock and a modem connected to the modem port.

The other day I tried for the first time to use the PB 210 + modem without the MiniDock. Result "the serial port...may already be in use". I had disabled AppleTalk. I have been unable to locate what is wrong.

Equipment: PB Duo 210, System 7.1, upgr 3, FreePPP 2.5, Sportster 28.8 external modem

>name removed wrote
>>I had an identical problem with my 210.
>>This solution worked for me. Turn off AppleTalk twice.
>>
>>1) using the Chooser --
>>Click on the button "AppleTalk Inactive
>>
>>and 2) using the AppleTalk Control Panel.
>>Choose "user mode" from the edit menu of the AppleTalk Control Panel. >>Select "advanced"
>>Click on the "options" button in the main control panel window
>>Select "inactive"
>>Close the control panel and restart.
>>
>>This was suggested by a representative from Olympus, when I was having >>trouble getting my camera to connect to the Modem/printer port. I am >>using System 8, so the dialog boxes may look a little different.
>>
>>Alternatively, a simple method is simply to remove the Appletalk control >>panel from the System folder and restart.

Let us all know how you get on Smile

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Tried it all

Thanks DrBunsen for your massive help!

I tried pratically all I read in the links and in the quotes you provided, with no avail: the problem persists.

The problem is that the MIDI interface is not sensed by OMS Setup. I'll give it some more try, then, if nothing good happens, I'll revive my (very) slow, (quite) old, (scandalously) cute Classic Colour to replace the Duo to run Galaxy Plus.

---
Roberto Giannotta
Trieste, Italy

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More memories

I do remember that I was connecting the Duo direct to a synth (Roland PMA5) that had a PC/Mac serial port, not through a MIDI interface. I'm not entirely sure if I was using OMS, or going direct from the sequencer's own serial setup. I remember trying both MIDIgraphy and a really old version of Logic (1.6 or 1.Cool, and I'm not sure if both of them worked or only one.

I would very much like to be kept informed about the hardware hacks mentioned in this forum - good luck everyone.

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Tried with to-host connection: still nothing

Having read about your positive experience with the Roland PMA5, I've just connected my old Yamaha MU10 (a diminutive XG module which can work also as a MIDI interface) to the Duo directly through a serial cable to see if a to-host connection can make some difference for my situation - it can't (at least using the MU10).

Metrophage, you seem to have found the cause of this problem: did you succesfully performed your hack on your PB 1400?

And, equally importantly to me: does anyone know if the MOTU Pocket Express is an interface with "real transmitter and receiver chips"? (I have been offered one, albeit for a scandalously high price: 50€)

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OK, what about an Opcode Studio 128X?

For my PB Duo, I've just bought (for $20.50) an Opcode Studio 128X MIDI interface. It shoud arrive in a couple of weeks (bought on eBay US - now, it's a long way to Europe!).

Does anyone know if it is better or worse than the Opcode Studio 4? Most of all, does it sport "real transmitter and receiver chips"?

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Opcode Studio 128x: working with the Duo

Just to keep you informed: as expected, the Opcode Studio 128x interface is working with the Duo.

The only negative thing now is that the interface is actually bulkier than the Duo itself! Shame the Duo doesn't work with a compact «dumb» interface...

Roberto Giannotta
Trieste, Italy