Rare RCA control panel from 1966 may be the only surviving example of its kind.
A RCA Spectra 70/35 computer control panel from 1966, discovered in a collapsed garage. Credit: SonOfaDeadMeme / Reddit
Recently, a Reddit user discovered a rare RCA Spectra 70/35 computer control panel from 1966 in their family’s old collapsed garage, posting photos of the pre-moon landing mainframe component to the “retrobattlestations” subreddit that celebrates vintage computers. After cleaning the panel and fixing most keyswitches, the original poster noted that actually running it would require “1,500lbs of mainframe”—the rest of the computer system that’s missing.
As it turns out, the panel had been sitting in the garage for decades without the poster’s knowledge. “In short my house is a two-family, my dad used to rent out the other half before I was born,” explained SonOfADeadMeme in the thread on Friday. “One of the people who rented out the apartment worked at IBM (apparently the RCA Spectra 70’s were compatible with IBM sets from the time) and shortly before he left he shown up with a forklift and left something in the garage.”
A view of the RCA Spectra 70/35 computer control panel before (right) and after (left) its owner cleaned it up. Credit: SonOfaDeadMeme / Reddit
The equipment remained hidden for decades due to the deteriorating condition of the structure. “The garage was very dilapidated and has since collapsed so no one bothered going in. Fast forward a few decades and I found the RCA terminal and a crate labeled ‘Return to IBM San Jose,'” SonOfADeadMeme wrote. They speculated the unidentified IBM component in the crate was “something power supply related” but noted they hadn’t examined it closely due to their basement being “jam-packed with stuff.”
To operate the Spectra 70, users typically used a teletype (similar to an electronic typewriter) or video terminal console hooked to the machine that provided an interactive text-based experience. By contrast, the panel discovered in the garage appears to be the maintenance control panel for the Spectra 70/35 computer itself that would have been mounted on the side of the main processor cabinet, as seen in illustrations in RCA’s documentation. It features the main “Power” button to turn on the computer as well as multiple rows of indicator lights (including Q0-Q13 visible in the photos), various control switches for system operations, and a “Memory Address Stop” panel for debugging, and it prominently displays the “70/35 SYSTEM” designation.
A close-up of the RCA Spectra 70/35 control panel as it would look illuminated from behind. SonOfaDeadMeme / Reddit
What makes the discovery particularly interesting is that no photographs of this particular 70/35 RCA computer panel seem to exist online, though we found a few vintage examples of similar ones (like the 70/45) from photo archives and scanned PDFs on sites like bitsavers.
Since the discoverer wrote in a Reddit comment that they owned an Android “RCA tablet” when they were 9, we’re guessing that the machine hails from an era that must seem very unfamiliar. In a short interview Ars Technica conducted with the poster through Reddit, SonOfADeadMeme described some of the wonder they felt when they realized how rare the panel truly is.
“First time I found it in the garage about 4 years ago I didn’t fully realize how rare it was,” SonOfADeadMeme wrote to to Ars. “When I decided to start researching it more thoroughly, that’s when the real gravity of it set in. Of every photo I could find of the set, just one photo was modern, but out of all the photos (past and present), none of them I could find are of a Spectra 70/35. They are all 70/45’s and 70/55’s. It’s surreal having something you didn’t make that you can’t find a photo of you didn’t take.”
A rare piece of computing history
A view of an installed RCA Spectra System 70 computer system, complete with many peripherals, as seen in a 1965 RCA marketing brochure. A maintenance panel similar to the garage find can be seen on the far-left side of the image. Credit: RCA
In the mid-1960s, the RCA Spectra 70 series represented RCA’s attempt to compete directly with IBM’s System/360 mainframe computers, which were the dominant architecture at the time. According to Wikipedia, RCA introduced the Spectra 70 line in 1965 (and shipped it in 1966) and offered software compatibility with the IBM systems, allowing businesses to switch hardware vendors without rewriting their programs. The systems also made a few 1970s TV appearances in shows like The Incredible Hulk and The Bionic Woman.
RCA didn’t just clone IBM with the Spectra models; it innovated using what was then called “third-generation” computer technology, including integrated circuits to reduce power draw and overall size. RCA’s own marketing materials from 1965 promoted the systems as featuring “the industry’s first monolithic integrated circuitry in full-scale systems.”
The Spectra 70 family included five models: the 70/15, 70/25, 70/35, 70/45, and 70/55, with progressively more capable memory speeds and capacities. Operators could configure the system with up to 32,768 bytes of memory (32K), achieved by combining two 16,384-byte core memory modules—a respectable amount for the mid-1960s, though minuscule by today’s standards. By comparison, a decade later, the Apple II personal computer could utilize up to a maximum of 48K of memory.
A view of operators using an RCA Spectra 70/45 control panel similar to the one found in the garage, circa 1965. Credit: RCA
SonOfADeadMeme believes the 70/35 panel ended up in his family’s garage as a keepsake from the computer’s decommissioning. “I think the system may had been dismantled at IBM and the guy kept the terminal as a souvenir unfortunately, searched high and low while it was still standing but only other computers there was a Apple IIE and a Compaq that I think got tossed (kept the Apple II but cant find the Compaq). I did make sure to pretty much clean the whole place out before the collapse though,” they explained.
RCA discontinued the Spectra series in 1971 when the company exited the mainframe computer business, making surviving examples increasingly scarce. The company sold its computer division to Univac, which briefly continued supporting existing Spectra installations before phasing them out entirely.
As for the control panel’s future, the original poster has creative plans for this piece of computing history. “Unfortunately I don’t think I’m ever finding the other 1,500lbs of mainframe needed to use the luxurious 34 kilobytes of memory so I may (without altering a single Goddamn thing) string some LEDs behind the front panel and set them to blink at random.”
Benj Edwards is Ars Technica’s Senior AI Reporter and founder of the site’s dedicated AI beat in 2022. He’s also a tech historian with almost two decades of experience. In his free time, he writes and records music, collects vintage computers, and enjoys nature. He lives in Raleigh, NC.
