GDSX (Extended General Device Support) Manual

Design and Development
Extended General Device Support (GDSX) Manual—529931-001
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Using D-Series Features
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Specify any necessary access method control details.
Using D-Series Features
A converted application is one that has been modified to use some extended feature of
the D-series operating system. An unconverted application uses no extended features
of the D-series operating system. TSCODE assumes that USCODE is converted if
and only if d^plus^enabled of the CONTROLFLAGS configuration parameter is set to
1. In other words, if USCODE is a converted application, d^plus^enabled is set to 1. If
USCODE is unconverted, d^plus^enabled is set to 0.
Converted Application Features
For converted applications, the following statements are true:
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TSCODE assumes that USCODE is converted.
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TSCODE supports GDSX being run either at a high PIN or at a low PIN (of course,
USCODE must be designed and coded to support the desired mode of operation).
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TSCODE internally opens $RECEIVE with the file system procedure call
FILE_OPEN_, and intercepts and forwards D-series-format system messages to
individual USCODE tasks.
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TSCODE maintains control blocks using the D-series format for internal data (for
example, process handles and process descriptors).
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TSCODE assumes that any process identifier used by USCODE will be a D-series
process handle
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TSCODE stores a file name as a variable-length string whose length in bytes is
specified as a separate integer value.
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GDSX can open and be opened by external high PIN processes. GDSX can
create high or low PIN processes.
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TSCODE allows USCODE to call all D-series service routines and most C-series
service routines. Illegal calls to other C-series service routines receive file-system
error 29 or 560.
Unconverted Application Features
For unconverted applications, the following statements are true:
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TSCODE assumes that USCODE is unconverted.
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GDSX may only be run at a low PIN.
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TSCODE internally opens $RECEIVE with OPEN, and intercepts and forwards
C-series format system messages to individual USCODE tasks.