[Info-vax] BASIC and AST routines

[Simon Clubley]

On 2021-11-23, Arne Vajhøj <arne at vajhoej.dk> wrote:
>
> 2) Why are those arguments there?
>
> It is not obvious to me why Macro-32 code would want to use them
> any more than C or Basic code.
>

Nor to me. In an OS with the proper levels of abstraction, those
hardware-specific registers simply should not be needed (or even
visible) to a function used as the target of what is essentially
just another way of doing an asynchronous callback to a function
within an application.

Since they are visible, and since they are of no use to a normal
compiled language, there must be some cases where you have to
preserve these values manually in Macro-32, whereas a OS based
around a higher-level language would have its compilers generate
the correct code sequences for you without you having to worry
about any of this at all.

Simon.

-- 
Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP
Walking destinations on a map are further away than they appear.