[net.micro.mac] Resume

darin@tmq.UUCP (Darin Adler) (05/13/85)

> 
> Writing a resume procedure is no mean feat.  Since exit to finder
> doesn't rebuild the system heap from scratch your takings some risks in
> letting the finder attack on your disks at that point.  Consider what
> happens if it rewrites a disk's directory without checking that the
> directory is absolutly pure and noble, bye bye data ...
> ... My only use of this feature is to get some oportunity to look at
> things prior to the machine rebooting.

I have used resume procedures that allow a "Save and Quit" or "Quit" option
(similar to the ones in MacWrite).  It is true that the system heap may be
mangled ... maybe a warning to the user is in order.  I have not had trouble
using a resume procedure - I have resumed many time without noticing ill
effects, so I think that destruction of the system heap is fairly rare.

Darin Adler
ihnp4!tmq!darin

robw@dartvax.UUCP (Robert H. Wills) (05/16/85)

Further to the question of resumption:
Why does the mac run entirely in supervisor mode? Surely the state of
the OS could be better  preserved if applications ran in 68000 user mode..
Of course, to do it properly, you need memory management, as in the Lisa
or later  680x0 chips.

Rob Wills
Thayer School of Engineering
Dartmouth College                       (robw@dartmouth)