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- STSORBIT PLUS Revision History
- ------------------------------
-
- Each released version of STSPLUS uses a four digit revision code such
- as 9218. The first two digits indicate the year and the second two digits
- indicate the week of the year. In some cases, an additional letter suffix
- is added to distinguish changes occurring within the same week or to
- identify special versions. A partial week at the beginning or end of the
- year is counted as a full week. Using this method, a year will typically
- have 53 weeks although it is possible to have 54 weeks in a leap year (1972
- is an example). The current year-week revision code is shown on the Julian
- Date display, Display Mode 7, in my program ASTROCLK.
- This file records the revision history of program STSPLUS through all
- of the minor twists and turns that usually accompany the evolution of such
- a complex program. It illustrates the tortuous process of maintaining and
- refining a program as ideas and problems are reported from every quarter.
- These notes may also be helpful to users who are upgrading from one version
- to another to find out what has changed.
-
- David H. Ransom, Jr.
-
-
- Version 9219 -- April, 1992
- ---------------------------
- -Version 9219 corrects a minor bug in the circles of visibility for the
- user's location, the alternate location, and the tracking stations. These
- circles were incorrectly shaped in Version 9218 due to a minor error in the
- formula that crept in during testing. (The circle of visibility for the
- spacecraft was correctly shaped and all numerical data were correct.)
- -Versions 9204 through 9218 ignored bad checksums in 2-line elements but
- did not read the data correctly. This has now been repaired and a bad
- checksum on either data line is reported but otherwise ignored and the data
- read correctly.
- -Several minor typos were corrected in this documentation.
-
-
- Version 9218 -- April, 1992
- ---------------------------
- -Version 9218 is the initial formal release of program STSORBIT PLUS and
- now includes complete program documentation. The beta releases included
- only update notes to the original STSORBIT 9134 documentation. While the
- STSORBIT PLUS documentation borrows heavily from that original STSORBIT
- documentation, many sections are new or have been rewritten and updated.
- -I had planned to modify STSPLUS for dual satellite operation but this
- proved more difficult than expected. After many hours of work, I have put
- that feature aside, at least for the present. The basic structure of the
- program does not lend itself to multiple satellites; this is particularly
- true of the multi-layered graphics features. The processor workload was
- also increased substantially, making things even more difficult for the
- many users without a math coprocessor chip. Finally, given the other
- demands on my time, a complete rewrite from scratch would simply require
- too long. I'm sorry to disappoint those who asked for that feature ...
- especially the folks working on Mission STS-49.
- -In order to eliminate problems due to changes from one program version to
- another, STSPLUS now ignores all data from different versions of file
- STSPLUS.INI and the program must be initialized as if being run for the
- first time. Only .INI files written by the same program version will be
- accepted. Trying to maintain backward compatibility with all prior versions
- of the .INI file has become both difficult and time consuming -- and has
- not always been successful. Too many problem reports have been due to
- corrupt or incompatible .INI files, sometimes from versions dating back
- several years.
- -There have been many changes from Beta Version 9206, too many to describe
- in detail here. Even "seasoned users" of STSPLUS should check this
- documentation carefully!
-
-
- Beta Versions 9139 thru 9206
- ----------------------------
- -Beta versions released for testing and comment. Version numbers included
- 9139, 9145, 9146, 9148, 9202, 9203, 9204, and 9206. Significant changes and
- improvements were incorporated in these releases, often the result of user
- feedback. Many thanks to those who sent in bug reports and suggestions!
-
-
- Beta Version 9137 -- September, 1991
- ------------------------------------
- -Initial public beta version.
-