Getting rectread / rectwrite commands to work on IRIS 4D-70 G

[Tim_Buxton at UM.CC.UMICH.EDU]

  We need a workaround, or better, SGI implementation of rectread
and rectwrite commands, since they are the fastest way to do the
graphics moves we require.  Both commands are documented as working
for our G-level machine, but having the temerity to USE them brings
a brisk rebuff at run-time - command not implemented.  A call to
the hotline produced little - yes they know of the problem, yes
it will be fixed in the (alas, indefinite) future.  We have a 
prerelease version of fortran 3.2, in which it is still not fixed.
This must be bugging users by the thousands, judging by how
slowly our workarounds have worked so far, and how fast the commands
work on GTX machines of our acquaintance.  Thanks in advance for
any help we can get here.  I have already found this forum
very helpful, especially the apropos scripts.
 
             - Tim Buxton, OptiMetrics, Inc.
               Tim_Buxton at um.cc.umich.edu