From: db3l@ans.net (David Bolen)
Subject: Re: OS/2 help needed!  comm and speed problems, etc.
Date: Fri, 11 Sep 1992 01:31:04 GMT
Organization: Advanced Network & Services, Inc. - Elmsford, NY

In article <BuDyJD.KL3@andy.bgsu.edu> jzawodn@bgsu.edu (jeremy zawodny) writes:

>     When using Telemate 3.01 in a dos session (full screen) I
>try to switch to a window (ALT-HOME) and when I do, Telemate
>stopps communicating with the modem.  It doesn't stop communicat-
>ing, it dies altogether.  I have a 16550 AFN on board and am
>using the beta com drivers for OS/2.  I don't know if I have the
>settings correct, but I have COM_DIRECT_ACCESS OFF, COM_HOLD ON,
>and COM_SELECT ALL.  And yes, background execution is turned on. 
>By the way, I am trying to communicate at 57.6kbps.

You may not be able to get a COM program in a DOS box to go that fast
reliably.  A couple of things to try would be allowing direct access to
the COM port (via whatever that setting is - I don't have the beta drivers
myself), or if that doesn't help, at least make sure that you have used
the MODE command (in OS/2) to set the COM port to BUFFER=ON (and RTS=HS if
your modem uses hardware flow control).

Beyond that, I'd suggest going to an OS/2 package.  The virtual COM driver
can only generate a 1000Hz interrupts or something close to that, and you
may just be trying to drive the virtualized COM port too fast.

>     In frustration, I tried to use TE/2 instead.  I couldn't
>even get it to talk to com4.  What's wrong?

I'm not familiar with TE/2, so I don't know if that's a intrinsic limitation.
Perhaps someone else can answer this one.

>Problem #2: Memory and Speed
>
>     I have 20megs of memory but don't need all of it to load
>applications into.  I would like a sizable hard disk cache (2meg
>or so) to speed up OS/2.  Can I do this?  How can I do this?
>     There is a line in my config.sys file something to the
>effect of "DISKCACHE=384,LW"  What does that mean?  LW?

It's dependent on the filesystem you are using.  For any of your FAT
partitions (and the floppy), the DISKCACHE line controls things.  The number
is the size (in Kbytes) of the cache, and the LW turns "lazy writing" on.
Check out the command reference (look in the Information folder) for more
details.

If you have an HPFS drive, then the size of the cache is set in the /C: option
on the IFS= line that loads HPFS.IFS.  Lazy writing is activated by running
the CACHE.EXE program (in config.sys, RUN=, or later from the command line)
with the /LAZY:ON option.  It's enabled by default if your C: is HPFS.
For further information, see "CACHE" or "IFS (HPFS.IFS)" in the command
reference.

>     While I'm at it, what do the following lines mean, too (also
>taken from my OS/2 config.sys):
>
>     THREADS=256
>     MAXWAIT=3
>     PRIORITY_DISK_IO=YES
>     CODEPAGE=437,850

These are also all documented in the online command reference as are all,
or at least theoretically all, of the commands you can use on the command
line, in batch files (non-Rexx) or in config.sys.  Briefly:

	THREADS  = Maximum active threads (execution contexts) in system
	MAXWAIT  = How long a regular priority thread waits (in s) before
		   OS/2 will automatically increase its priority.
	PRIORITY_DISK_IO = Gives foreground processes priority for disk
		   I/O over background processes.
	CODEPAGE = Specifies one or more character sets that can be used on
		   the system.  Provides internationalization support.  In
		   your case, 437 is the US code page, and 850 the
		   multilingual.

>     In addition, can I have a ramdisk under OS/2?  If so, how
>can I do this?  If not, why not?

Sure - just load the VDISK device driver.  See "DEVICE (VDISK.SYS)" in the
online command reference.


Basically - check out the online command reference.  It'll give you more
detailed information on all of your Problem #2.

--
-- David
--
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