From: gtaylor@vme.heurikon.com (Gregory Taylor)
Newsgroups: comp.music
Subject: Re: MIDI Interface & Powerbook 100
Date: 31 Dec 92 15:17:11 GMT
Reply-To: gtaylor@vme.heurikon.com (Gregory Taylor)
Organization: Heurikon Corporation, Madison, WI

Hugo_Jackson@mindlink.bc.ca (Hugo Jackson) writes:
>Well, here's the problem, my Mac Powerbook 100 won't drive my opcode systems
>inc. midi translator.
>Has anyone used a powerbook 100 to drive a midi translator, and if so, which
>one was it.

You've done well for yourself in that the 100 (in the absence of the
new Opcode OMS fix) is currently the only powerbook that DOES actually
run (and by "run" I mean that it takes IN huge steaming hunks of MIDI
data as well as spits it out). When MAX and I need to do something, I'm
using a really cheap little MIDI interface (I wanted something as small
as I could find), and it works like a charm.

Here's a posting from some kind folks in the know which might elucidate
your difficulties, or at least comfort you:

___________
This letter contains the sum of Atomic City's current knowledge of
MIDI with respect to the Apple Powerbook computers, containing the
findings of recent tests of the 100, 140, and 170, combined with
late-breaking new results. We hope you find it useful.

A. THE POWERBOOK 100

The 100 works fine if you keep in mind that it's only a 16MHz 68000;
Finale can make it choke. Old versions of Alchemy won't boot, but
that's not a PB problem. The "big name" software we were able to try
(Performer, Vision, Cubase, UpBeat, Galaxy, and MAX) runs fine. It's a
good idea to disable Appletalk, and have software up and running under
MIDI Manager. (Actually, on the 100, you MUST disable AppleTalk, as it
will grab and munge the only available port for MIDI, the printer
port.)  If you use Opcode stuff, OMS goes a long way toward
deglitching your work. We weren't able to test everything in the
universe (the test occurred as part of a recording session, not as an
end in itself, but that fact got trimmed from the article in EM), but
here are some highlights....

1. The older version of the MTP desk accessory won't run, but the
MTPII utility, which runs under MIDI Manager, should be fine. In
Nick's words: "The MTP-II DA will run with MIDI Manager, so using that
(via OMS for example) should be OK (and this is the main reason that
I'm considering buying an MTP-II). I don't know if the MTP-II DA runs
on a PB100 using its own drivers. Oh, unless I'm mistaken, the MTP-II
software is a proper application rather than a DA; but I could be
wrong."

The PB100 can run reliably at MIDI speeds - just. Any faster
communication speed (such as MTP's fast handshake) will not work
reliably. To be honest, I've never (in two years of MTP use) notice
any improvement in using fast handshake.If that limitation is
understood and nothing faster than ordinary 1MHz mode is attempted,
the PB100 printer port can handle the MTP, MTPII, and any Opcode
interface up to but possibly not including the Studio 5.

2. MAX handled a patcher designed on the IIci, one that was designed
to kill portables (and really hung up an Outbound 2030 badly), on the
PB100 without breaking a sweat. Nick points out that MAX performance
can be sluggish on the PB100 with really big patchers, but that's true
of any Mac-- you just have to determine the limits of "really big" by
trial and error with your particular platform. I should point out that
Nick uses MAX as a controller-data remapper for live performance with
CASSIEL, and places tremendous burdens both upon the code and the
computer running it.

3. UpBeat ran like a dream.

4. The worst timelag we got with Performer pumping eight MIDI streams
of arpeggios through the MTP from another Mac into the PB was about
2 milliseconds. Not a major issue.

5. Galaxy handled input and output of bundle data from the worst synths
in our rig, the Roland D-70 and Korg Wavestation EX, without a hiccup.
Repeated attempts could NOT produce a failure with ANY synth SysEx dump.
We tested Oberheim, Sequential, Korg and Roland gear without a hitch.

6. Vision and Cubase were not tested as extensively as Performer, but
they run, do not lose input data, and no noticeable timing glitches
were found, although the torture tests weren't as heavy-duty as the one
for Performer. I am currently using Vision on my PB100 with an Opcode
MIDI Translator interface, and it works like a charm.

B. THE POWERBOOK 140, 145, AND 170

Nick Rothwell owns a PB140, which he only considered reliable for
output (it lost a LOT of data on input, not just long sysex dumps.
Apple was wrong on that point, as on many other points) until a recent
Tech Note suggestion by Apple was augmented and implemented by Opcode
in a new version of OMS, 1.2beta. Under 1.2b, the input problem is
solved, but incoming data loses its timestamping. We're still testing
just how bad a problem these 6 msec hiccups can be. NOTE that this fix
only works for interfaces attached to the Modem port!  The printer
port is and always will be unreliable, apparently, for input. In his
own words, Nick says: "I haven't hammered my machine heavily yet (and
won't be doing until the next live project I have to prepare, in which
case I'll be using both PowerBooks), but the tests I did (including
SMPTE lockup) suggested the PB140 is OK. 6msec isn't too bad, but you
can hear/feel that length of time." The 170 should have no differences
in performance than the 140 or 145.

C. FUTURE DESIGNS

According to the latest technical data, the 160 and 180 will suffer
from the same problems as the 140, 145, and 170. There is not enough
data available to render a judgement on the Duos. We are not authorized
beta testers of these machines, and cannot promise any early results
at this time. If we do learn something of use, we will see to it that
the Editor of EM, who has been very kind and helpful in his efforts
to relay our findings to a larger audience, will hear of it and pass
it along.

We hope this helps possible Powerbook buyers with any decision they
make.  Our findings neither carry nor imply any guarantees from
ourselves or any of the manufacturers involved (especially Apple!).

We would, in closing, like to compliment Opcode on the excellent
reliability of OMS on the Powerbooks, and to thank Doug Wyatt for the
1.2beta patch that renders the costlier Powerbooks at least partially
reliable.( We would also LIKE to express our opinion of Apple's
handling of the whole MIDI question, Powerbook and MIDI Manager
support included, but we'll refrain for legal reasons.)

Please feel free to write or email me with any comments; we do not plan
any addenda to this study at this time, but circumstances may change.

Dr. Michael Metlay
Atomic City Productions
P.O. Box 81175
Pittsburgh, PA 15217-0675
metlay@netcom.com

Many thanks to Dr. Nick Rothwell of CASSIEL for his technical expertise,
and to Mr. Eirikur Hallgrimsson of DEC for his input and encouragement.
___________
--
The law moves quickly in the rain/and chokes the world with memorials./The
courts accept the lowest superstition/into evidence. And we embrace quickly in
the rain,/conceiving a hale infant with hands to wrinkle/the bedsheets toward
it, wave by trough by wave./Gregory Taylor/Heurikon /Madison, WI/608-828-3385