Fear and Loathing in EPROMs

In a previous post I mentioned how I used an ancient Kantronics KPC-3 terminal node controller in my high altitude balloon project.  It takes the transmitted location data and converts it so a computer can understand it.  As it turns out, it wasn’t a simple plug-and-play affair.

First off, I should mention that I bought the used KPC-3 on eBay.  It didn’t come with a case and the manuals came on a burned CD.  This should have been enough of a red flag.  However, I hooked it up, turned it on, and immediately saw an output on my terminal program running on my PC.  It even asked me for my amateur radio call sign.  Unfortunately, after that I received nothing but errors and freezes.  I read in the manual that there is a hard reset procedure that will reset all settings and perform a check on the firmware and RAM.  Perfect.  I performed the reset and the firmware failed the checksum.  Let the troubleshooting begin.

I searched all over for others with this problem.  It basically came down to a bad EPROM chip that holds the firmware.  I’ve never dealt with EPROM before and there’s a reason for that, it’s ancient.  Luckily, I found a blog called Freeman’s Garage that talked about programming EPROMs for the KPC-3.  I followed his advice and bought a Willem PCB5.0E programmer and a few 27C512 EPROM chips.

The programmer boasts about having USB, but I discovered that it only uses this for power.  Guess what it uses to program?  A parallel port.  Who the hell has one of those anymore?  First I purchased a parallel to USB cable, but it ended up being specific to printers and was basically worthless.  So I bought a parallel port card for my computer.  I could not get this to work with the programmer’s software at all and I received tons of errors every time I started it up.  So I went to the internet again.

As it turns out, several issues were the cause of my problem.  First, the programmer’s software doesn’t work well with 64-bit Windows 7.  Second, a parallel port card has a different memory address than a built-in parallel port.  I struck gold when I stumbled across this site.  This guy ran in to the same combination of problems as me and completely rewrote the interface driver to work with 64-bit Windows 7 and non-standard parallel port addresses.  Talk about lucky.

I simply put his driver in the installation directory and everything worked flawlessly.  I uploaded the KPC-3 v8.2 firmware from Freeman’s Garage and my KPC-3 was up and running like new.

In the end I wasted a bunch of time and money learning to burn EPROMs when I should have been able to hook everything up and move on.  Hopefully those trying to use a KPC-3 in the future will heed my warnings and at least buy one with a case, preferably from a reputable source.  If not, then hopefully I’ve helped ease your suffering.


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