View Full Version : RCA Spectra 70 Series

October 15th, 2014, 06:27 AM

I was reading about the RCA Spectra 70 series of computers. They seem like rather neat boxes with interesting early usage of IC's at a time when Germanium transistors where the norm.

Does anyone know of museums or collectors who have any of these systems?

Does anyone have war stores from working on them?



December 7th, 2014, 12:07 PM
I think they were the first 1 mHZ processor machine or something like that, right?

December 7th, 2014, 01:08 PM
Germanium? The Spectrolas were introduced after the S/360 and used some of the first (RCA-manufactured) integrated circuits. Silicon ruled supreme then.

Maybe no original RCA-branded operating hardware, but they were also rebadged by Siemens and English Electric. Eventually morphed into the Univac 9000 line--there shouldn't be much of a problem finding examples of those.

Notable for me in that they were one of the easier mainframes of the period to microprogram.

December 7th, 2014, 02:52 PM
I can never decide if the Spectra series, which were also made and sold in the UK by English Electric and later ICL as System/4 were a great idea or a half fudged clone of System/360.

On the plus side the interrupt processing was much faster, but that meant you couldn't run any IBM systems software. I can't see any reference to the system calls so I have no idea if IBM applications were usable or if they still needed to be re-compiled to run...

December 7th, 2014, 05:25 PM
If memory serves (and it increasingly doesn't nowadays), the resident internals of the OS were different, but instruction-wise, user applications were the same. If you reported to RCA instead of IBM after a hard night, it might take you until your second cup of coffee to figure out that you weren't in Poughkeepsie any more. Compare the Spectrola's TDOS with S/360 DOS JCL, you might not notice. Assmbler mnemonics where identical as far as the user was concerned--you started your program the same way--BALR x,0, USING *,x and ended it with a SVC (or a macro to generated one).

Given the differences between other manufacturer's machines and IBM's, RCA was pretty darned close.

(FWIW, the popular nickname "Spectrola" dates from the time when the Radio Corporation of America (RCA) purchased the Victor Talking Machine Company (the US branch only; other countries had their own versions, so "JVC" = Japan Victor Company) and was for some time, known as "RCA Victor"--and the merged company for a time held onto the trade name "Victrola" for their record players.)

December 9th, 2014, 08:07 PM
Took a look at a brochure for the /45. It appears that you could order the IBM emulation for a number of systems with your Spectra. Not an expert but yes I agree clearly RCA marketed their Spectras as capable of IBM emulation among other things. They also talked up the hardware speed and microcircuitry as well.

December 10th, 2014, 11:06 AM
Have you a link to that. I can see several manuals on Bitsavers but not that one!. I notice the other dig at IBM in the sales brochure, where it says you won't get bogged down by the OS!.

April 8th, 2017, 01:46 PM
I just came across this thread. I worked for RCA back in the '70s' as a field service tech (they called us 'CSRs'). There was an experimental version of a hypervisor running at one client's installation that would load OS/360 as a virtual application. It would report "Model not supported" after start-up, but then would operate normally. I don't think it ever went into production, though.

April 8th, 2017, 04:03 PM
Germanium? The Spectrolas were introduced after the S/360 and used some of the first (RCA-manufactured) integrated circuits. Silicon ruled supreme then.

But no Magic Brain.


April 8th, 2017, 04:48 PM
My recollection is that the Spectrolas were probably the most early S/360-type machines for do-it-yourself microprogramming. I remember a red book that talked about rolling your own on the RCA machines and the S/360 Model 30.