Phil's RT85

By Phil Rice VK3BHR 25 Feb. 2002

Standard Disclaimer

Here's a small program, (written in C) to generate the EPROM contents for an RT85. This program is ONLY for the "Low band" RT85, NOT the RT85A or B or C. It may be vaguely relevant to these other models: I don't know, as I have only the one radio to play with. Using information from here, you should be able to modify the program to suit your radio.

This program is "a work currently in progress". I have got both the receiver and transmitter VCOs "on frequency" and the receiver scans through up to 32 channels. There are probably a few things the program should do (but doesn't). It seems to work.

On my radio, I unsoldered the EPROM, installed a "machined pin" socket, unsoldered the "strip" connectors and resoldered them so they were raised from the board a couple of mm. I can now program the 2716 in a standard programmer.

Here's my code:

• The source code for you to play with.

• How the channel code seems to be formatted.

• The list of channels and frequencies (read by program)
  The last entry must finish with a "return" (just press "Enter" or "Return")
  Each entry contains the channel number, receive frequency in KHz and transmit frequency in KHz.

• The list of channels to scan (read by program) in the order you want them scanned (maximum of 32)
  The last entry must finish with a "return" (just press "Enter" or "Return")

• And for the "compiler challenged", here is a DOS executable.

Modifying the radio's hardware

• An excellent set of notes by Roger Baker VK3BKR and Mark Detering VK3TLW

And here's some useful things I found on the web

• A heap of excellent programming information by Chris

• Mr. Skinny's RT85 page has some pictures of the RT85.