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General Category => Off topic => Topic started by: ComSoft6128 on 01:04, 23 February 18

Title: Sometimes 128KB can take you a long way
Post by: ComSoft6128 on 01:04, 23 February 18
Extract from article by Alex Christian in Shortlist magazine 21/2/18:

The space shuttle Endeavour

“To fly, you type instructions into the keyboard panel. It’s in hexadecimal – primitive programming language. The shuttle had extremely limited computer memory. The software to fly the entire shuttle was around 128KB – equal to two Commodore 64s. Above the commander’s seat are the main computers of the shuttle where the memory resides.

The full article is at:

https://www.shortlist.com/tech/inside-the-cockpits-of-a-space-shuttle-f-16-fighter-jet-and-porsche-919-hybrid/346592

Worth a look.

Cheers,

Peter





Title: Re: Sometimes 128KB can take you a long way
Post by: Vyper68 on 17:17, 23 February 18
Extract from article by Alex Christian in Shortlist magazine 21/2/18:

The space shuttle Endeavour

“To fly, you type instructions into the keyboard panel. It’s in hexadecimal – primitive programming language. The shuttle had extremely limited computer memory. The software to fly the entire shuttle was around 128KB – equal to two Commodore 64s. Above the commander’s seat are the main computers of the shuttle where the memory resides.

The full article is at:

https://www.shortlist.com/tech/inside-the-cockpits-of-a-space-shuttle-f-16-fighter-jet-and-porsche-919-hybrid/346592 (https://www.shortlist.com/tech/inside-the-cockpits-of-a-space-shuttle-f-16-fighter-jet-and-porsche-919-hybrid/346592)

Worth a look.

Cheers,

Peter

I think the Voyager 1 & 2 Spacecraft had computers in them less powerful than a ZX81 but look at what they acheived  :)
Title: Re: Sometimes 128KB can take you a long way
Post by: ||C|-|E|| on 20:13, 23 February 18
Wow, but 128KB filled in pure hexa is a lot to fill! you can write more than 100K instructions in there  :D I assume they limited the amount of memory to make it as robust and reliable as possible (just think about the vibrations) and radiation hardened. Magnetic fields must had been crazy in there.
Title: Re: Sometimes 128KB can take you a long way
Post by: Gryzor on 20:10, 25 February 18
Very interesting page: http://www.cpushack.com/space-craft-cpu.html


Quote
Voyager used the same computer as the Viking Orbiter in only one of its 3 computerized subsystems (the Command and Control Subsystem).  The Attitude and Articulation Control Subsystem used an augmented version of the CCS computer that inserted a unit (the Hybrid Buffer Interface Circuit (HYBIC)) between the CPU and RAM, which intercepted instructions to add indexed addressing capability (at the expense of other instructions), and accelerated instructions that used idle cycles. The third computer, used in the Flight Data Subsystem, was a new custom design in CMOS with a 128 register, nibble-serial CPU and 8096 words of 16-bit RAM. It ran about 80,000 instructions per second.


Quote
the computer on the Viking Orbiter were General Electric 18-bit TTL machines (not 12-bit) with a bit-serial, single register accumulator and bit-serial access to plated-wire RAM (4096 words).  It executed around 25,000 instructions per second. The Viking Lander computers (Honeywell HDC 402) were a different design with 18,000 24-bit words of plated-wire RAM.