Retrofitting

Retrofitting is the process of adding new features, components, or systems to an existing product—features that were not part of the original design. One of the most significant retrofitting project I've done in my twenty-fives years with ST Electronics is upgrading the disc drive system on the RADCOM test station for the Republic of Singapore Air Force (RSAF).

Believe it or not, the RADCOM test programs—the very heart of its ability to diagnose E-2C avionics—were stored on magnetic cartridges. Not hard drives as we know them today. Not solid-state memory. Magnetic cartridges, about the size of a three-stacked 15-inch pizza, mounted in an HP7906 disc drive and run off an HP1000 host computer.

Over time, the disc access heads of the HP7906 drive built up ferrite dirt. Microscopic particles, accumulated through normal operation, clinging to the heads that read the magnetic media. And when those dirty heads passed over the cartridges, they could cause a head crash—the read head literally scraping against the magnetic surface, scratching it, destroying the data.

It happened more often than anyone liked. Cartridges that had worked for years suddenly became unreadable. Scrap. Trash. Years of test programs, lost to a few microns of ferrite dust. The RSAF was desperate. They had approached Grumman Aerospace—the original equipment manufacturer—for help. Grumman came back with an interim upgrade solution. Price tag: 1.5 million US dollars.

The RSAF project manager reached out to us. After researching for alternative solutions, we decided on the magneto-optical (MO) drive. It uses laser and magnetic technology together, writing data to discs that were far more robust than magnetic cartridges. No head crashes. No ferrite dirt. No scratched media. More importantly, it could be configured to emulate older storage devices. To the host computer, it would look exactly like an HP7906 disc drive. The system wouldn't know the difference. The test programs would load and run exactly as before.

Over the following months, we transferred hundreds of test programs from their vulnerable cartridges to the robust MO discs. Each migration was verified. Each program was tested. By the end, the entire RADCOM test suite lived on media that wouldn't scratch, wouldn't crash, wouldn't fail. 

The cost to the RSAF? Less than half of what Grumman had asked.

The project manager called me after the final acceptance to personally thank me. I appreciated the sentiment. But the real reward was seeing those MO drives spin up day after day, month after month, never losing a single byte of data.

Another obsolescence issue resolved—this time through retrofitting.

Ps: You can read the details and more in my latest book, A Memoir of Electronics, Discoveries, and a Life Less Ordinary by clicking on the book title.