stephenbuck
Experienced Member
A sub-thread of Bendix G-15 Restoration
One of the first things you discover when you start exploring the G-15 is that numbers are represented in base 16, but the hexadecimal (Greek root) A-F "digits" are not used for values 10-15. Instead, they use sexadecimal (Latin root) "digits", where the values 10-15 are represented by the letters U-Z. Here's more than you ever wanted to know about sexadecimal.
The Bendix Programmer's Reference manual offers this (hilarious) definition:
"Hexadecimal" became a standard with IBM 360 Fortran
The now-current notation using the letters A to F establishes itself as the de facto standard beginning in 1966, in the wake of the publication of the Fortran IV manual for IBM System/360, which (unlike earlier variants of Fortran) recognizes a standard for entering hexadecimal constants. As noted above, alternative notations were used by NEC (1960) and The Pacific Data Systems 1020 (1964). The standard adopted by IBM seems to have become widely adopted by 1968, when Bruce Alan Martin in his letter to the editor of the CACM complains that with the ridiculous choice of letters A, B, C, D, E, F as hexadecimal number symbols adding to already troublesome problems of distinguishing octal (or hex) numbers from decimal numbers (or variable names), the time is overripe for reconsideration of our number symbols. This should have been done before poor choices gelled into a de facto standard!"
Bendix tried to make it easy
One of the first things you discover when you start exploring the G-15 is that numbers are represented in base 16, but the hexadecimal (Greek root) A-F "digits" are not used for values 10-15. Instead, they use sexadecimal (Latin root) "digits", where the values 10-15 are represented by the letters U-Z. Here's more than you ever wanted to know about sexadecimal.
The Bendix Programmer's Reference manual offers this (hilarious) definition:
"Hexadecimal" became a standard with IBM 360 Fortran
The now-current notation using the letters A to F establishes itself as the de facto standard beginning in 1966, in the wake of the publication of the Fortran IV manual for IBM System/360, which (unlike earlier variants of Fortran) recognizes a standard for entering hexadecimal constants. As noted above, alternative notations were used by NEC (1960) and The Pacific Data Systems 1020 (1964). The standard adopted by IBM seems to have become widely adopted by 1968, when Bruce Alan Martin in his letter to the editor of the CACM complains that with the ridiculous choice of letters A, B, C, D, E, F as hexadecimal number symbols adding to already troublesome problems of distinguishing octal (or hex) numbers from decimal numbers (or variable names), the time is overripe for reconsideration of our number symbols. This should have been done before poor choices gelled into a de facto standard!"
Bendix tried to make it easy
