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Fortran II Hypersource

(texdraft.github.io)

79 points texdraft | 3 comments | 18 Nov 24 07:10 UTC | HN request time: 0.417s | source

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fsckboy ◴[18 Nov 24 16:23 UTC] No.42173921[source]▶

>>42170423 (OP) #

you buried the lede in the lead, where it links:

See also LISP 1.5

https://texdraft.github.io/lisp-1.5/listing.html

finally! being able to take the actual CAR and CDR!

replies(1): >>42174328 #

1. aap_ ◴[18 Nov 24 16:59 UTC] No.42174328[source]▶

CAR here and CDR just below: https://texdraft.github.io/lisp-1.5/listing.html#line-7626

replies(2): >>42176111 #>>42176751 #

2. fsckboy ◴[18 Nov 24 19:41 UTC] No.42176111[source]▶

>>42174328 (TP) #

thanks for finding that, i love it!

3. nyrikki ◴[18 Nov 24 20:42 UTC] No.42176751[source]▶

>>42174328 (TP) #

For those not familiar with these old IBM machines that used decrementing of the index registers, this will help explain all the ??D instructions are there.

https://bitsavers.org/pdf/ibm/704/24-6661-2_704_Manual_1955....

Another lens for the FORTRAN case specifically, in the modern way we tend to say Fortran arrays are 'one' indexed, looking at this old code it is sometimes useful of thinking of it as a limit index, pulling from n-1 -> n. Or at least I found that useful for myself when digging into some of this a long time ago.