Alex Freed wrote:

>> 4. U4 and U11 are not normally populated. This is expansion space that
>> I wired for a USB module and a GAL for glue logic. It can be used for
>> some other interface too.
>>
>> what are your plans for this?
> 
> With all the payed for cards in the mail I got back to the one I made
> for myself and plugged in the DLP USB module
> 
> http://www.dlpdesign.com/usb/dlp-usb245mv15.pdf

What's a good source for these in small quantities?  DigiKey?

> assisted by a GAL16V8 as glue logic. Same could be done with several
> TTL chips, but I prefer a single chip solution even if it needs to be
> programmed. This combination worked right away with my extremely
> simple "echo" test

Have you posted the equations?

(snip)

> A number of uses come to mind:
> 
> 1. The main purpose - a convenient way to exchange data with a PC.
> Need some guru's help to make this port accessible as a CP/M "device".

If you want support in the OS, it needs to act as PUN: and RDR:.  A better 
solution might be to write a MEX overlay that treats the USB logically as a UART.

Are there any comm programs available for Windows (or Mac, for that matter) 
that can use the USB port?

> 2. Convenient debug output for a CP/M program.
> 3. A way to load the DOS 3.3 RAMDISK from a PC. If there are sources
> for the code.

> 4. Very simple code loaded to the z80 will make this port available to
> the 6502. The z80 code will just reroute data from it's address to USB
> and back until 6502 resets the z80. Beats the heck out of SSC in speed.

I wonder if that setup can be used to emulate an Appletalk interface?  Have to 
give it some thought.
--- SBBSecho 2.12-Win32