Freed Z80 USB port - Success!

[Steven Hirsch <snhirsch@gmail.com>]

All,

Can't keep this to myself :-)  About 10 minutes ago, I was able to 
successfully transfer files back and forth between minicom on my Linux box and 
the ZMP comm program on the Freed Z180 card.  All of this over a USB 2.0 
connection.

Getting USB working was quite a battle, complicated by the fact that the base 
circuit board did not connect everything that was needed.  I assume because 
this functionality was in a prototype phase.

I have a configured ZMP that I will be glad to make available to anyone that's 
following in my footsteps.  The I/O routines are quite stupid at the moment 
and are doing everything in "byte at a time" mode, perhaps the most 
inefficient way to use the packet-based USB bus.  Next round I will implement 
a receive buffer to drain incoming data a block at a time.  Should speed 
things up considerably (even though it's not too bad now).

I can burn GAL devices for anyone that wants to get this going.  Just be 
warned that you'll need to do some jumpering on the rear of the card with 
wirewrap wire.  Not rocket science, but it requires some journeyman soldering 
skills.

Steve