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- ID:AS IBM AS/400 Terminal Emulation Setup
- Desqview Technical Note #
- By Dan Sallitt
-
- The IBM AS/400 is a terminal emulation setup akin to the 5250. It
- usually requires two or three files in config.sys and two loaded
- from the command line to get it going, followed by a number of
- other files to implementvarious functions.
-
- The sizes of the basic AS/400 files that are listed below are
- accurate for the early 1990 versions of IBM's AS/400 software.
- Some of these files are smaller in later releases.
-
- Drivers
- -------
-
- EIMPCS.SYS 1K
-
- ECYDDX.SYS 21K - a block device, which means that
- Quarterdeck's DEVICE.COM cannot load it
- from the command line
-
- FSDD.SYS 59K - only needed to create virtual drives
- on the AS/400. ECYDDX.SYS must be loaded
- before it. Later versions of the AS/400
- software may replace FSDD.SYS with the TSR
- STARTFLR.
-
- TSR's
- -----
-
- E5250AH.COM 8.2K - manages the PC's terminal emulation
- hardware. Different cards can be used for
- AS/400 connection, and each requires a
- different TSR to manage it - this file
- manages the 5250 card. A TSR that is
- often used instead of E5250AH.COM is
- called WSEAH.COM.
-
- STARTRTR.COM 56K
-
-
- 1) One of the cards that the AS/400 software can use, the 5250 card
- (and maybe others as well), puts a piece of RAM, 8K or so in size,
- at xC00 (usually CC00). QEMM 5 and other memory managers may not
- see this RAM. In addition to excluding this area on your memory
- manager, you should probably use the RAM parameter with QEMM (or,
- if you are on an 8088 or 80286 machine and using a memory manager
- that provides mappable pages between 640K and 1024K other than the
- page frame, use Quarterdeck's QRAM to map these pages). Otherwise,
- E5250AH.COM may access various sections of the reserved memory area
- when it loads, and DESQview's XDV may crash on startup if all these
- areas aren't excluded. Loading Quarterdeck's Manifest after you
- load E5250AH.COM, and examining the QEMM-386/Analysis screen, is a
- good way of finding out what areas to exclude. The Analysis screen
- may advise you to exclude some areas inside the expanded memory
- page frame as well as mappable areas outside the page frame; it
- should be necessary, however, only to exclude areas outside the
- page frame.
-
- Giving E5250AH.COM the parameter /Mx (where x is the same as above-
- C by default) seems to make it access fewer areas, though the areas
- that are accessed still need to be excluded if you don't use the
- RAM parameter or otherwise map all available areas between 640K and
- 1024K before the AS/400 software loads.
-
- For example - if you are using QEMM-386 and IBM's 5250 card and
- have determined that the card uses the CC00-CDFF area, your QEMM
- line in the CONFIG.SYS file should look like this:
-
- DEVICE=C:\QEMM\QEMM386.SYS RAM X=CC00-CDFF
-
- ...and you should load E5250AH.COM with the following parameter:
-
- E5250AH /MC
-
- You should then examine QEMM/Analysis screen, and put further
- exclusions on QEMM if any areas on this screen (other than the page
- frame area) are labeled "Exclude."
-
- 2) In earlier versions of IBM and Quarterdeck's software, STARTRTR
- did not like to load inside DV, which meant that everything before
- it couldn't load in DV. Even at that time, many other AS/400
- functions loaded after STARTRTR would load in a window - we have
- seen STF.COM load and run in a DV window. We have verified that
- the version of STARTRTR dated 5-26-90 can run unsuccessfully inside
- a DESQview 2.31 window. We are not sure whether revisions of
- STARTRTR or of DESQview were responsible for resolving early
- conflicts.
-
- On one system that we saw, STARTRTR used an interrupt that can
- cause conflict with DESQview (INT 69). Because it is likely that
- DESQview will always avoid using this range of interrupts when the
- AS/400 drivers are loaded in the CONFIG.SYS file, this is probably
- not a problem for current DESQview users. However, users of DV
- 2.30 and later can do themselves no harm by giving DESQview the
- startup parameter /XB:68 when they run STARTRTR inside DV.
-
- 3) On some systems, after STARTRTR is run, users run a program
- FSPC.COM to make a virtual disk on the mainframe. This program
- isn't resident and takes no memory. However, FSPC needs to see
- FSDD.SYS, and in earlier versions of the IBM and Quarterdeck
- software it couldn't from inside a DV window. We believe that
- this is no longer a problem with DESQview 2.31 and the mid-1990
- release of the AS/400 software.
-
- 4) STARTRTR will need 160K of space to load high, even though it
- only uses 56K or so after it has loaded.
- 5) Some AS/400 drivers and TSR's know about expanded memory and
- store something there. Therefore, some of the memory figures that
- I've quoted may increase in the absence of expanded memory.
-
- 6) If you run the AS/400 software inside DV, it may or may not be
- necessary to set Keyboard Conflict to 8. One user thought he
- needed it set to 9, though this report is not substantiated.
-
- 7) In some versions of the IBM AS/400 software, the driver FSSD.SYS
- and the non-resident FSPC.COM are united in a smaller TSR
- STARTFLR.COM. Early versions of STARTFLR crashed in a DESQview
- 2.26 window in much the same preemptive way that
- early versions of STARTRTR did; we have reason to believe that,
- even on systems in which STARTRTR runs successfully in DESQview,
- STARTFLR may fail in a DESQview window when QEMM-386 is present
- and in an ON state. This information is not yet confirmed.
-
- 8) When loaded high with QEMM 5.00, ECYDDX.SYS would fail with an
- error message like "Keyword invalid." QEMM 5.11 is able to load
- ECYDDX.SYS high successfully. It is possible that including a
- single space after the word ECYDDX.SYS on the appropriate line in
- the CONFIG.SYS file may help QEMM 5.00 load ECYDDX high, but this
- has not been tested.
-
- 9) The AS/400 utility STF has difficulty loading high with both
- QEMM 5.00 and QEMM 5.11. QEMM's LOADHI /GS feature reports that a
- version of STF from mid-1990 needs a region of approximately 26K to
- load successfully; however, on at least one system, this version of
- STF.COM reports that it has insufficient memory to load even when
- loaded into a 79K region of High RAM. It is possible that STF.COM
- is making the assumption that it will be loaded below 640K, and is
- becoming confused when loaded above 640K; it is also possible that
- LOADHI /GS is somehow not detecting the correct amount of memory
- that STF.COM needs to start up. We have not investigated this
- further at the time of writing.
-
- Copyright (C) 1991 by Quarterdeck Office Systems
- * * * E N D O F F I L E * * *