| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 2044.1 | PASPORT INTERFACE PROBLEM | TROA01::HITCHMOUGH | | Wed Jan 10 1990 13:05 | 22 |
|
Rather than start a new note I'll put my problem here.
HELP!! My MAC/Passport interface has gone up the creek.
At random occurrences I get dropped bits which causes
"MIDI DATA ERROR" on my TX802 and random program changes/glitches
on this and my S 330.
This happens on i/p to the MAC and playback as I checked it with
MIDISCOPE and put the 330 in MIDI monitor mode.
The problem is random enough that I could not see it with a scope.
I've taken the unit apart and resoldered all the connections and
made sure the cable sockets are not loose but the problem remains.
Sometimes it will go for a while and suddenly drop a bit (usually
B7 the status bit) and I get the error.
The interface is one of the simple Passport one in one out units
that cost $170 Canadian for about $20 parts.
Any suggestions on what may be the problem...schematic..etc?
|
| 2044.2 | | 4GL::DICKSON | You could be an ocarina salesman | Wed Jan 10 1990 13:24 | 4 |
| You don't by any chance have a long cable between the Mac and the box,
do you? I did this once and got "midi data errors". The midi data
rates are too high for that cable to be over a couple feet long.
(Midi cables themselves, of course, can be much longer.)
|
| 2044.3 | | TROA01::HITCHMOUGH | | Wed Jan 10 1990 15:47 | 9 |
| Good suggestion, but no. I use the one that came with the box, its
about 18 inches or so long. I did notice some very high frequency
damped oscillations on the clock pulses which could be symptoms
of what your saying so I'll check that somehow.
Thanks,
Ken
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| 2044.4 | infer what you want from this | NORGE::CHAD | Ich glaube Ich t�te Ich h�tte | Wed Jan 10 1990 16:59 | 5 |
| I had this problem (or something similar) when my MIDI cable went underneath
my computer's monitor (ATARI monochrome monitor). I layed a few layers of
aluminum foil between the two and it stopped.
Chad
|
| 2044.5 | Almost gone. | TROA01::HITCHMOUGH | | Wed Jan 31 1990 14:17 | 17 |
| Well, its "sorta" fixed. First I removed a MAC clock INIT because
I heard that there is potentially some impact with the MAC timer
which would affect MIDI output.
Then I gave th back of the circuit board with stiff brush and some
Freon (What ...all those CFCs!!!) especially around the cable
connector from the MAC.
The problem hasn't totally dissappeared because I get the odd bum
note at random, but not very often.
I have since put the clock INIT back and the situation remained
the same, so I can only assume it was dendritic growth on the p.c.
board that I removed by cleaning.
Thanks for the replies.
Ken
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