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Silicone on Sapphire
03-14-2016, 04:06 PM
Post: #21
RE: Silicone on Sapphire
(03-14-2016 10:43 AM)BillCRAV Wrote:  
(03-14-2016 08:14 AM)jebem Wrote:  A simple search show that RCA had at least another microprocessor commercially released as a kit in early 1975: the COSMAC 1801 on which the 1802 was based and released one year later in 1976.

Concerning release dates, this page here have plenty of it and based on actual support documentation.



Is it acceptable that actually discrete 4000 CMOS series were used instead of an already commercially available SOS microprocessor to build that computer?
Yes, it is (I did it in mid 70's as well for a school project), but this is kind of speculative until someone comes up with the actual official papers showing us what was the actual technology used in that spacecraft.

Also, SOS technology was being developed at that time to be used for the military and space applications in some kind of secrecy, way before it was commercially available to the general public.
In the end what we can read in the Internet is mostly noise.

The 1801 dual-chip was basically the "development version" of the 1802, and afaik was NEVER made as SOS. Afaik, NO ONE used it commercially.

It's NOT speculative that 4000 CMOS were used in the Voyagers. It is in the design specs and documentation, which were worked on "WAY before" the 1802 was commercially available, especially when using it would have been "bleeding edge" development, which is NOT what NASA et al. did.

"SOS technology was being developed at that time to be used for the military and space applications in some kind of secrecy, way before it was commercially available to the general public." is EXTREMELY speculative and most probably untrue.

You keep producing statements without showing were are you getting that information.
Why must I believe in what you are telling as being more correct than what Peregrine Semiconductors are telling?
Reasoning is fine here, but until we see some clear information on the technology used, all you can say is speculative as well.

I'm not saying that the 1802 was used in the Voyager (never did) but I'm interested to know the true as much as you do.

Jose Mesquita
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07-31-2016, 05:46 AM (This post was last modified: 07-31-2016 05:47 AM by BillCRAV.)
Post: #22
RE: Silicone on Sapphire
(03-12-2016 03:03 AM)jjohnson873 Wrote:  {snip}

I worked for RCA when they were manufacturing SOS technology in their Findlay, OH wafer fab. It was often used in space applications since it was resistant to SEU (single event upset) and it was a very low power process. The RCA CDP1802 8-bit microcontroller was used in many space applications and was, at the time, one of the very few SOS microcontrollers that also was capable of low power. Some of you may even remember that this microcontroller had a FORTH compiler and the people who used FORTH swore by its efficiency. It was probably the only micro that had a SEX instruction in assembly (selects one of the 16 registers to be an index register).
~ Jim J. ~

Hi. I'm trying to get an as absolute as possible fix on CDP1802 chips created in Silicon-on-Sapphire.
So far I haven't been able to find any documents that make certain, sure, absolute comments that
can't be interpreted one way or another.

I have found absolute documentation that some CDP chips were created as SOS at Sandia Labs.
(RAM and ROM and some others) But not the 1802. (as in maybe, maybe not)

I haven't seen any mention of "Findlay, OH", as SOS or anything else in relation to RCA.

Some 1802 people think all 1802 chips were SOS. But I have found documentation that says they WERE created as "bulk silicon", which I believe means they were NOT SOS.

So ANY information you have about this issue would be greatly appreciated.
As much as you remember might point me in the direction to find the documentation we need.
At the very least we will have a first-person 'anecdotal' source.

Thanks.

CRAV Computing Hobbyist
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