Subject: HDX for the TI

From: Gregory McGill <[email-masked]>
Date: Wed, 9 Jan 2013 09:11:05 -0800

I just built my first HDX daughter board for the TI rs232 card.  I had a
spare card that was already socketed for the DSR chip so that saved a lot
of desoldering and such. Ordered the parts from mouser, they had everything
in stock except for a 24 pin connector which I had to jerry-rig from a
"forked" connector they had in stock.

Assembly was easy, just soldering work. Fred's design page is easy to
follow. His pictures on the site for modifying the RS232 card are also easy
to follow. Cut one resistor off, snip a trace or pin for the interrupt and
add a few jumpers from the daughterboard to the main rs232 card and it's
done.

The DSR loaded first try, no errors :)   The one thing I didn't catch in
the docs first read was that the standard RS232 port is port 1, and the
HDX1 port is port 2 in the TI rs232 standard. So to test I had to build a
RS232/2 adaptor/split cable..

Still have to add a switch for the interrupt line so I can switch back to
interrupts (the HDX mod doesn't require interrupts to operate and you cut
the trace to make it work without a dsr until you can load one)

Now I can type OLD HDX1.APERATURE  and it loads that game in TI BASIC off
my PC's hard drive. also can open HDX1. in DM2k and view the directory on
the PC side.  Print to HDX1.PRINTER and it comes out on TIprint on the same
PC using the PC's cheap printers.

Essentially a file and print server for the TI!

Greg