jwabik@shamash.cdc.com (Jeff Wabik) (05/09/89)
Hi .. I'm having some problems getting MIDI gear running with my A1000..
Here's the scoop.
I bought a MIDI interface from a local Amiga dealer. The Interface
is made by a company called "ECS". The interface has 5 I/O connectors,
two serial ports, and three 5-pin (at 45 degrees) DIN ports. One serial
port to attach to Amiga, the other is for a separate serial device (via
switch-selectable serial pass-thru ... A nice feature). The DIN
ports are for MIDI "IN", "OUT", and "THRU".
I am using a standard null-modem cable for the serial attachment of the
A1000 to the MIDI Interface.
The musical device I am implementing is a Casio CT-460 keyboard. The
Casio has MIDI IN/OUT ports only.
My cabing goes from MIDI-OUT on the Casio to MIDI-IN on the Interface,
and MIDI-IN on the Casio to MIDI-OUT on the Interface. Serial out on
the A1000 to Serial in on the Interface. Serial out of the Interface
to my modem.
I rented "Music Construction Set" to see how well it worked with the
MIDI interface. I have no other MIDI-compatible software.
In trying to be cost effective about this, I decided to build my own
cables. Near as I can tell MIDI uses only three of the 5 assigned pins.
In this configuration:
3
2 4 <-- Use your imagination and picture
1 5 these in a semi-circle.
Pin 3 seems to be the ground, pin 2 is +5V, and pin 4 is the signal.
On the knowledgeable advice of several in comp.sys.amiga, I wired
pin 1 to 1, 2 to 2, ... 5 to 5.
The problem: Nothing works.
When I activate MIDI mode with Deluxe Music Construction Set (DMCS),
RTS and DTR go high on the serial bus. (I've got one of those
cute little tester deals with the LED's).
When I "play the keyboard" (using the mouse) in DMCS, data *IS*
transmitted to the interface, but is NOT transmitted to the Casio..
(i.e. The transmit data lite on my tester deal flashes, but, the
keyboard does not respond. Voltages on the MIDI-out pins of the
Interface do NOT appear to change.)
When I play the Casio keyboard, data may or may not be transmitted
to the interface, and is definitely not transmitted to the Amiga.
(i.e. The "receive data" lite on my tester deal does NOT flash.
Volatages on the MIDI-IN pins of the Interface do NOT appear to
change.)
I've tried to check voltages and such on each pin, but, without any
hardware documentation (the docs that came with the Interface say,
"Will provide hours of fun and entertainment. By the way, there is
no warranty.", and that's about it.) I have no clue what I'm testing
for.
I've got some INCREDIBLY limited documentation on how all this MIDI
stuff works. I assumed that, as usual, I'd plug it together and it
would magically work. Wrongo. When I tell the software to accept
input form the Casio, data is not received (by the software). When I
tell the software to play on the attached MIDI device, data is not
received (by the keyboard). I can't get anything to work, anytime, or
anywhere. I've narrowed it down to either being the Amiga, the
Interface, the keyboard, the cabling, or the software, but am not sure
which is at fault .. 8^)
If there's anyone out there who's had experience dealing with MIDI,
this type of Casio keyboard, or Deluxe Music Construction Set, please
get back to me, either by posting here, or via e/mail. There's
a digital musician in me just dying to get out.
Thanks in advace. ..
-Jeff
--
Jeff A. Wabik E/Mail: jwabik@shamash.cdc.com AT&T: +1 612 853 6811
____ ____ FAX: +1 612 853 4789
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| |___ ___| | Control Data Corporation - Fool me once, shame on you;
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"We pledge allegiance to Beach, Biceps, and Beer .."cmcmanis%pepper@Sun.COM (Chuck McManis) (05/09/89)
In article <12517@shamash.cdc.com> jwabik@shamash.cdc.com (Jeff Wabik) writes: >Hi .. I'm having some problems getting MIDI gear running with my A1000.. >Here's the scoop. Great, but in the future don't post the question to *both* comp.sys.amiga and comp.sys.amiga.tech. In this case, the question is about using a peripheral with your Amiga, an excellent question for comp.sys.amiga, if it asked how to build a MIDI interface it would be .tech material. See the difference? >I am using a standard null-modem cable for the serial attachment of the >A1000 to the MIDI Interface. This is your first problem. The MIDI interface is expecting you to connect a straight through connector from the Amiga to the MIDI interface. Not only that but it wants all 25 pins so that it can draw power from your A1000. The interface is an _active_ device that needs the power so 7 wire cables are definitely out. Use the that cable on the serial connector of the ECS box that you connect to your modem or whatever. >My cabing goes from MIDI-OUT on the Casio to MIDI-IN on the Interface, >and MIDI-IN on the Casio to MIDI-OUT on the Interface. Serial out on >the A1000 to Serial in on the Interface. Serial out of the Interface >to my modem. These are the correct connections. (With the caveat that the cable between the Amiga and interface should have 25 pins) >In trying to be cost effective about this, I decided to build my own >cables. Near as I can tell MIDI uses only three of the 5 assigned pins. >In this configuration: > > > 3 > 2 4 <-- Use your imagination and picture > 1 5 these in a semi-circle. > >Pin 3 seems to be the ground, pin 2 is +5V, and pin 4 is the signal. >On the knowledgeable advice of several in comp.sys.amiga, I wired >pin 1 to 1, 2 to 2, ... 5 to 5. Well, even if you are being cost effective you really should stop by the library sometime. Look for a book called "MIDI for Musicians" which has not only a good description of MIDI but schematics for a simple interface as well. Your guesses on the cable are incorrect. Pins 2 and 4 are a "current loop" interface, Pin 3 is the ground and should only be connected at one end (to prevent ground loops) [All this is explained in the book]. >If there's anyone out there who's had experience dealing with MIDI, >this type of Casio keyboard, or Deluxe Music Construction Set, please >get back to me, either by posting here, or via e/mail. There's >a digital musician in me just dying to get out. Get either a 25pin straight cable or make one with 25 conductor ribbon cable and two 25pin insulation displacement connectors. Everything will then work as advertised. --Chuck McManis uucp: {anywhere}!sun!cmcmanis BIX: cmcmanis ARPAnet: cmcmanis@sun.com These opinions are my own and no one elses, but you knew that didn't you. "A most excellent barbarian ... Genghis Kahn!"
dwl10@uts.amdahl.com (Dave Lowrey) (05/09/89)
In article <12517@shamash.cdc.com> jwabik@shamash.cdc.com (Jeff Wabik) writes: >Hi .. I'm having some problems getting MIDI gear running with my A1000.. >Here's the scoop. > >I bought a MIDI interface from a local Amiga dealer. The Interface >is made by a company called "ECS". The interface has 5 I/O connectors, >two serial ports, and three 5-pin (at 45 degrees) DIN ports. One serial >port to attach to Amiga, the other is for a separate serial device (via >switch-selectable serial pass-thru ... A nice feature). The DIN >ports are for MIDI "IN", "OUT", and "THRU". > >I am using a standard null-modem cable for the serial attachment of the >A1000 to the MIDI Interface. > Are you sure you want to use a Null Modem? I would think that the device would want just a regular "25 wire" pass through cable. -- ------------------------------------------------------------------- "What is another word for 'Thesaurus'?" Steven Wright Dave Lowrey Amdahl Corp. Houston, Texas (713)-850-8828 ...!{ames,sun,decwrl,uunet,....}!amdahl!dwl10 [ The opinions expressed <may> be those of the author and not necessarily those of his most eminent employer. ]
addison@pollux.usc.edu (Richard Addison) (05/10/89)
In <12517@shamash.cdc.com> jwabik@shamash.cdc.com (Jeff Wabik) writes: >Hi .. I'm having some problems getting MIDI gear running with my A1000.. >Here's the scoop. : : >I am using a standard null-modem cable for the serial attachment of the >A1000 to the MIDI Interface. The problem is that your MIDI Interface box needs a super-set of the "standard" RS-232 serial port signals. In particular it needs +5V (pin 21) and -5V (pin 14) to power the signal converters. Thus you need a cable that connects at least pins 2, 3, 7, 14, and 21 straight through from the back of your 1000 to the MIDI Interface box. You may need other signals for whatever you connect on the pass-thru. Now, if you had a 500 or 2000 connected to a MIDI Interface box designed for a 500 or 2000, you would need +12V (pin 9) and -12V (pin 10) for power. If you had a 500 or 2000 and wanted to connect a MIDI Interface box designed for a 1000, you would also need a couple of resistors and Zener diodes to go from the +/-12V on the serial port of the 500/2000 to the +/-5V expected by the MIDI box. Hope this helps, Richard Addison "This is only an emergency. If this had been an actual test we would have required that you bring a number 2 pencil. We now return you to your regularly scheduled programming."