I learned C in the late 1970s (although most of my programming back then was in FORTRAN, Assembly, and Pascal). Around the same time I was using a ones-complem

I learned C in the late 1970s (although most of my programming back then was in FORTRAN, Assembly, and Pascal). Around the same time I was using a ones-complement system, a CDC 6000 series machine. This was an important machine at the time. The CDC 6600 was the first “super computer” and was three times faster that the preceding fastest computer. The peculiar vagueness of the early C standards with respect to integers was probably due to the variety of hardware we used in the 1970s. For example: The CDC 6000/7000s had 60-bit words, ones compliment arithmetic, 6 bit chars (but machine addresses were only of the 60 bit words). The peripheral processors of the CDC machines (responsible for I/O) had 12-bit words as I recall. IBMs very popular 360 mainframes supported several native hardware number formats: twos complement, unsigned, zoned decimal (one decimal digit per 8-bit byte), and packed decimal (two digits per byte). I believe C was first developed on the DEC PDP-11. This was a very popular computer with 16 bit words and 8 bit bytes. It was twos complement, but mixed endianess (big endian for the 16 bit words making up a 32-bit long and little endian for the bytes in the 16-bit words). Other DEC computers of the 1960s used 12 bit program counters and accumulators; I did some assembly language programming on the PDP-6 (it cost $300,000 back then and 24 were sold). I seem to recall using a system with 18 bit registers and 9 bit bytes, but I can’t remember the details. One system that I did assembly language programming on for a year was the TI 960. This machine was notable because it had two separate 64KB address spaces, one for data and one for instruction, known as a Harvard architecture instead of Von Neumann architecture. The advantage of the Harvard architecture was that a program couldn’t inadvertently modify the code it was running, a frequent and difficult to untangle occurrence when programming assembly. The Von Neumann architecture became dominant because it didn’t chop the available memory in two and partly because self modifying code was believed to be sometimes useful (yikes).