[COFF] Re: [TUHS] Re: machine code translation,as mental architecture models

On Thu, 11 Jul 2024, Paul Winalski wrote: Does anyone know how extensively they used the macro facilities? You can write much higher level stuff as macros than as single instructions, which makes it a lot easier to do efficient translation. For example, on OS/360 you'd write a GET macro to retrieve the next record (or a pointer to it) from a file, which was a lot easier to figure out than the control blocks and subroutine calls the macros expanded into. The /25 and /30 were 8 bits internally and as slow as you would expect, but were still full implementations of S/360. IBM sold a lot of them. The /40 was 16 bits, /50 32 bits, and /65 64 bits. The later /85 was roughly a /65 reimplemented in faster logic with a cache and 128 bit memory, making it as fast as the more expensive /91 for programs that didn't use a lot of floating point. The /85 was microcoded and could emulate a 7094. All the S/360s from the 65 and down had microcoded emulators for They always ran faster, company policy. That's why you needed a 360/65 to emulate a 7094. Partly that, more that the emulators allowed the customers to spread the conversion work out partly before they got the new machine, partly after. Remember that the new machine was faster and had better peripherals. Since it was built with more modern components it may well have been cheaper to rent. The 5100 was indeed a marvel, but it was a very slow one. Regards, John Levine, johnl(a)taugh.com, Taughannock Networks, Trumansburg NY Please consider the environment before reading this e-mail. https://jl.ly