How programs get run: ELF binaries [LWN.net]

How programs get run: ELF binaries

Posted Feb 7, 2015 4:01 UTC (Sat) by felixfix (subscriber, #242)
Parent article: How programs get run: ELF binaries

The very first computer language I learned was FORTRAN II on an IBM 1620, the CADET (Can't Add, Doesn't Even Try) version with add tables instead of add circuitry.

Then I learned machine language for it, and delighted in knowing that 11 was add, 12 was subtract, while 21 was add immediate and 22 was subtract immediate (just reaching; those may not be correct!). My teacher and I began a contest to see who could get the most interesting program on a single 80 column card. I think he gave up when I got 120 digits of instruction with various nefarious overlaps. The program printed out THIMK over and over on the console typewriter. One sense switch would bypass a delay loop; a second halted the program. It couldn't print THINK because that M was the halt instruction.

I think I learned for more about useful programming in that summer than any class since.

How programs get run: ELF binaries

Posted Sep 8, 2018 2:23 UTC (Sat) by Since1969 (guest, #127103) [Link]

An IBM 1620 was my first computer, too. Model 1 with automatic divide and indirect addressing. No floating point instructions.

1* were the immediate instructions; 2* were the "storage-to-storage" ones.

My first program was computing Hero's Formula using "FORTRAN with Format". Later we got Load and Go FORTRAN, which saved a lot of trees. But after a few FORTRAN programs, I learned SPS (assembler). One of the coolest tricks was coding loops of different lengths which produced tones in various pitches in a nearby FM radio.

Great machine.