[Info-vax] Userland programming languages on VMS.

Arne Vajhøj arne at vajhoej.dk
Fri Feb 4 20:23:49 EST 2022


On 2/3/2022 9:15 AM, Simon Clubley wrote:
> On 2022-02-02, Arne Vajhøj <arne at vajhoej.dk> wrote:
>> On 2/2/2022 4:34 PM, Bill Gunshannon wrote:
>>> I would have to go back an look but I am pretty sure even after the
>>> advent of the C based Unix there were still pieces in assembler for
>>> quite some time.  I do not believe any of the current BSD's still
>>> have any except maybe 2.11 on the PDP-11.
>>
>> I would have thought any OS needed a few assembler code files
>> or some C code files with ASM directives or some C code with
>> system specific pseudo functions mapping to native
>> instructions. To get some of really HW specific stuff done.
> 
> That's for extremely low-level stuff such as initial boot code or
> interrupt dispatch code that dispatches to a C language interrupt
> handler.

I would expect some in process context switches as well.

And maybe something in the graphics driver.

> About the only time you would see assembly language in application
> programs is as tiny inline fragments called from a HLL if you needed
> direct access to a specific specialist CPU register (for example)
> and then you (and not the OS) are responsible for that assembly language.

I think that is getting extremely rare today.

Arne





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