From mboxrd@z Thu Jan 1 00:00:00 1970 From: michael at kjorling.se (Michael =?utf-8?B?S2rDtnJsaW5n?=) Date: Mon, 3 Feb 2020 18:36:25 +0000 Subject: [COFF] How much Fortran? In-Reply-To: References: Message-ID: On 3 Feb 2020 12:06 -0500, from crossd at gmail.com (Dan Cross): > Regardless, one DOES wonder in what capacity FORTRAN was used in the > mission. Was it used on the onboard computers, or was it used on the > downlink stations for e.g. data analysis? I would be _extremely_ surprised if the Voyager probes themselves run FORTRAN code. Maybe, possibly, just barely _might_, they run code that was compiled from FORTRAN code, but that seems unlikely. Somewhat less unrealistically, they might run software which was initially prototyped in FORTRAN, before being translated into something else. But even that seems a stretch. Adding up the numbers in [1], the memory capacity of each of the Voyager probes comes out to a total of 557,248 bits (not bytes), split between custom-built computers with 16 and 18 bit word lengths. Wikipedia summarizes it as "Total number of words among the six computers is about 32K." which seems about right; 557,248/17 ~ 32,779, and two out of the three computer pairs are said to use 18-bit words. For ground data processing systems to run code written in FORTRAN does however seem plausible to me. [1] https://en.wikipedia.org/wiki/Voyager_program#Computers_and_data_processing -- Michael Kjörling • https://michael.kjorling.se • michael at kjorling.se “Remember when, on the Internet, nobody cared that you were a dog?”