.SD 70;.PS 60,70
.LM 5
.B 3
.C 65; Overview and Installation Guide to IDX
.B 2
.C 65; 18-Apr-80
.B 3
.HL 1 Summary
.P 5
This document is an overview of the background and implementation
specifics of IDX, Version 2. The full user's manual to IDX is in the
runoff file, IDX.RNO, in the distribution UIC.
.P 5
Version 1 of IDX has been floating around for several years now,
though it lacked some "pretty" features that kept our installation
from using it as a reliable tool. This upgraded version started with
Version 1 as is, fixed up known bugs where possible, reworked several
modules that displayed some chronic problems, and after initial testing,
new features were added to supply full support to all valid 
FORTRAN-IV PLUS features.
.P 5
To those who are used to an older version of IDX, this version 
will seem very similar. The format of the cross-reference output
is the same as before, although several alternative formats were
tried and discarded as being more unreadable. The command line format
is also the same, although several switches have been added, among
them an /HE switch to provide instant help on the use of IDX.
.PAGE
.HL 1 Changes from Version 1
.HL 2 Parsing Algorithm
.P 5
Many small changes have been made to the parsing of the FORTRAN
statements to correct obscure bugs. The parsing algorithms have
been tested more rigorously than any other section of the program,
but there may be extremely rare FORTRAN constructs which may
give IDX problems.
.HL 2 EXTK$ Support
.P 5
For host systems which support the EXTK$ directive, IDX will allocate
its symbol table space on a pure demand basis, in increments of
2 Kwords. This increment can be changed by modifying an assembly
parameter in the STORE module.
.P 5
The basic algorithm and data structure for storing symbol values and
references is the same. Two differences are important: offsets
within a symbol table entry are now defined symbolically, and 
storing is done only within the last "frame" allocated via an EXTK$.
.HL 1 Installation
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Basically, the command file IDX.CMD should help you get from
wherever your UIC is to a task image of IDX. Just copy the distribution
into any UIC of your choice, and invoke IDX.CMD. If you want to task
build IDX into a privileged UIC, you had better log onto a privileged
account first.
.P 5
Most of the compile-time and build-time parameters for IDX are asked
for in the command file, such as default switches, memory increments, 
and INCLUDE statement nesting depth.
.HL 1 Documentation
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We have included a locally generated User's Guide for IDX in the
distribution, which includes the usage codes output by IDX in the
cross reference listing. Generally, any question about using IDX
can be answered therein. The .RNO file for the User's Guide has
been included so you can change the masthead of the document.
.HL 1 Support
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Of course, we aren't staking our lives on IDX, but we feel it gives
great support to all of FORTRAN IV-PLUS' features, and it has been
a great help to our FORTRAN programmers. If you happen to discover
any bugs that defy explanation, please forward them to us; we'll
see what we can do (If you make any enhancements, we'd like to find out
about them, also!).

