Portable MIDI options

[Magnus Danielson]

>>>>> "CL" == Christopher List <Christopher_List at Sonymusic.Com> writes:

 CL> Hello synth people -

Hi Christopher!

 CL> I was more than happy to receive a Toshiba Techra laptop from work (12"
 CL> display, 120MHz Pentium - yum yum). Unfortunately, I have since discovered
 CL> that this particlular PC has a parallel port (PP) which can be set to
 CL> either "Standard Bi-Directional" or "ECP" (some sort of enhanced mode that
 CL> is also bi-directional). The problem with this is that my old 2PortSE PP
 CL> MIDI interface will only work on a mono-directional PP. The same goes for
 CL> several other PP MIDI interfaces that I looked into - namely the Opcode
 CL> MIDI Translator and the Altech Traveller. I'm very disappointed because I
 CL> don't know how I'll ever be happy with this PC if I can't use it for
 CL> sequencing :).

 CL> My questions are;
 CL> 1. I don't even know what the difference is between "bi-directional" and
 CL> "mono-directional". Could someone give a technical description of why a PP
 CL> device like a MIDI interface would work with one and not the other.

To the best of my knowledge is the diffrence between a
mono-directional and bi-directional parallell port (leaving out ECP,
EPP and full IEEE 1284 ports) that the output enable of the output
buffer (a 74LS374 or similar) is in a control register rather than
being constantly earthed.

The only case I can see where this have an effect on your MIDI device
is when the software drives this bit such that the output buffer gets
disabled either all the time or sometimes.

 CL> 2. Would it be possible to use one of those jumper-wire connected DB-25
 CL> boxes on my PP to make it look like a mono-directional port to attached
 CL> devices? - Would this not make a difference due to problems on the software
 CL> side?

If my teory of your problem is right - no!

 CL> 3. Does anyone know of a PP adaptor that will work with a bi-directional
 CL> PP?

If my teory of your problem is right - you have a software problem.

 CL> 4. Does anyone know of a relatively inexpensive PCMCIA MIDI interface?
 CL> There are some PCMCIA sound cards with MIDI interfaces - but they are up in
 CL> the $500 range.

 CL> I ask here because I find these lists to be a more reliable source of
 CL> information than any tech support lines :).

I pulled this out of a quick websearch:
http://www.lvr.com/parport.htm
http://www.lvr.com/jansfaq.htm
http://www.fapo.com/ieee1284.htm
http://www.daewoo.fr/~fmathieu/1284.htm

Cheers,
Magnus