Tektronix 492 Spectrum Analyzer ROM and EPROM HEX Files

Tek 492 Memory Board
Tek 492 Memory Board

Having gotten my buddy Eks back on the air with new EPROMs for his Tek 492 spectrum analyzer, here are the Tek 492 ROM Images (← that’s the link to the file!) you’ll need to fix yours.

[Update: the comments for that post have pointers to other images and a clever hack to use a standard EPROM. If you’re not a stickler for perfection, that’s the way to go.]

They’re taken from a “known good” Tek 492, so they should work fine: the firmware verifies the checksum in each chip as part of the startup tests; if it’s happy, we’re happy.

Because WordPress doesn’t allow ZIP files, I tucked the HEX files into an OpenDocument file that also contains the pinouts and some interposer wiring hints & tips.

If you’re using the OpenOffice.org word processor, you’re good to go. Open the document and get all the instructions you need to extract the files and put them to good use.

If you’re not using OOo, then choose one of:

  • Install OpenOffice.org (it’s free software, so kwitcher bitchin’)
  • Futz with whatever Microsoft claims will import ODT files (if it doesn’t work, don’t blame me)
  • Just extract the HEX files and do whatever you want (if you know what you want)

The trick, explained in the document itself, is that ODT files are just ZIP files with a different file extension, so any unzip program will unpack them. You won’t see the HEX files in the document, you must apply unzip to the ODT file itself.

After unzipping, you’ll find three HEX files in the directory that originally held the ODT file, along with the collection of files that make up the OpenDocument document.

The only files you care about:

U1012 – 160-0886-04.hex
U2023 – 160-0838-00.hex
U2028 – 160-0839-00.hex

Use ’em in good health…

Oh, if you haven’t already figured it out, the DIP switch on your board is also bad. Saw the damn thing apart with a Dremel tool, pry off the debris, unsolder the pins, and install a new one. Just Do It.