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[DPRG] Shuttle computer question

Subject: [DPRG] Shuttle computer question
From: Kipton Moravec kip at kdream.com
Date: Sat Feb 8 10:40:07 CST 2003

The thing about the 8085 is that it is not CMOS.  It is NMOS or HMOS, which
is more radiation hardened than CMOS.  You do not want a radiation particle
to randomly flip a bit in the processor as it passes through. It tends to
make software screw up.

The 8085 got its name because it was Intel's first 5 volt microprocessor.
The 8085 was 100% software compatible with the 8080A with increased systems
performance. The initial 8085's were based on NMOS technology and the later
"H" versions were based on HMOS technology. (NMOS is Negative-channel Metal
Oxide Semiconductor, HMOS is High-Performance negative-channel Metal Oxide

The 8085 incorporated all the features of the 8224 (clock generator) and the
8228 (system controller) increasing the level of system integration. The
8085 along with and 8156 RAM and 8355/8755 ROM/PROM constituted a complete
system. The 8085 used a multiplexed Data Bus and required the 825X-5 support
chips. The address was split between the 8-bit address bus and 8-bit data
bus. The on-chip address latch of 8155/8355/8755 memory chips allowed a
direct interface with the 8085.

The 8085 family is also referred to as the MCS-85.


Back in 1978 I was programming COBOL on a 8085 computer for a medical
billing workstation.   I feel old...


----- Original Message -----
>From: <warm38 at juno.com>
To: <dprglist at dprg.org>
Sent: Saturday, February 08, 2003 6:19 AM
Subject: Re: [DPRG] Shuttle computer question
> My understanding is that the little robot running around on
> Mars has a RADIATION-HARDENED 8085 chip running the WindRiver
> RTOS and they had a problem with prioity inversion; loaded
> a patch and the little critter was off and running again.
> Radiation Hardened chips are RARE and not many are, other than
> the i8085.  I really cant imagine WindRiver running on the
> 8031, but then, I have a problem with WindRiver running on
> 8085 too.  Were they around way back then?  8-)
> wade in flour-dough
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