Need 286 Benchmark?

Tanner Andrews tanner at ki4pv.UUCP
Wed Aug 14 01:35:21 AEST 1985


] in above-referenced note, commentary is made about applications
] not developed on the intel advanced-elevator-controller-286 due
] to architectural ugliness.

Having here one of the aforementioned chips, and being the developer
of some huge code on these little monsters, I feel not only qualified
to comment but compelled by the frustrations.

Due to the problems of the segmentation, large (>64K in theory) arrays
are impossible.  Due to other bugs, the actual limit from malloc() is
32K.

Large programs must be built using special compiler options with which
no other machine in my experience is plagued;  option is required for
large (>64K code), and options to group code into segments are supplied
though due to bugs they don't work (tnx microsoft).  Building progs with
the larger code option makes bigger code, as code pointers grow to 32
bits.  Data pointers don't grow, which is a relief if it is necessary
to manipulate data -- but the old scheme of stashing a general pointer
into a (char *) no longer works!  Sorry, k&r.

There are lots of bugs associated with the unix/xenix and the c compiler
and libraries on this machine, and many of them are the result of casual
trust in the segmented architecture not to come along and give you a
kick in the sensitive locations.

Advice from a `286 user:  buy a 68K.  However, please note.  Applications
_are_ being developed on the miserable thing.  In C; the C used is not
changed to reflect any peculiarities of the '286.  The compiler options
are being used, of course; the Makefiles are thus different.  The code
is kept particularlyy "clean" so that it will compile and run under the
'286 as well as other, more sane, architectures.

There is also the problem of specifying segments to the debugger, and
making sense of arguments passed to functions.  I guess that has caused
as much frustration as anything with the segmented architecture.

-- 
<std dsclm, copies upon request>	   Tanner Andrews, KI4PV
uucp:					...!decvax!ucf-cs!ki4pv!tanner



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