                Memory
                ------

Former versions of Pasokon TV were rather picky about
memory requirements.  Since it was an old fashioned "16 bit"
application, it used the computer in "virtual 8086" mode.

This meant it could address only one megabyte of memory
directly and had to worry about the 640K "conventional"
memory limit and go through contortions to shuffle information
in and out of "extended" memory.  Memory managers, such
as EMM386 -- and especially QEMM -- added more overhead to
Input/Output (I/O) operations and interrupt processing.
It was not uncommon for the "machine too slow" message to
pop up on a '486 when a '286, without a memory manager,
was plenty fast.

Pasokon TV version 3 shatters these barriers to take full
advantage of the 32 bit architecture, virtual memory, and
other features of '386 and later processors.


Image Size
----------

Version 2 used images of 320 x 240 pixels with 32,000 colors 
for a total of about 150K memory for each image.

Version 3 uses images of 640 x 480 pixels with more than 16 
million colors for a total of almost a megabyte per image.
How can we store 10 images on a machine with only 8 Meg of
memory?


Virtual Memory
--------------

Instead of being limited to the amount of physical memory
available, Pasokon TV can act as if more is available.
When there is not enough physical memory available, portions
of the program and data which have not been used recently
are swapped out to disk.  For best results you will
want 8 megabytes of memory but it might be possible to get
along with 4.  You will just notice more disk activity and
some operations will be slower because more information
needs to be shuffled in and out of limited memory.  The
amount of "virtual" memory is limited by the amount of free
disk space.


Out of Memory Error
-------------------

This is not talking about physical memory or RAM chips in the
computer.  Instead it means there is not enough free disk 
available for swapping.  You should have at least 16 megabytes
of free disk space when running Pasokon TV.


Disk Space
----------

When you start up Pasokon TV, it looks around for a suitable
place to create a temporary file for swapping.  The search 
order is:

1. Use directory specified by TEMP variable.  
2. Use directory specified by TMP variable.
3. Search drives C: up until an invalid one is found.
   Use the one with the most free space.

The first two may require some explanation.  Many programs
create temporary files for various reasons and usually delete
them when finished.  Generally these will put them in the 
directory specified by the TEMP or TMP variable which is
usually set in the AUTOEXEC.BAT file.  For example:

        SET TEMP=C:\TEMP
        SET TMP=C:\TEMP

Be sure there is a directory by this name:

        CD \
        MKDIR TEMP

You can examine the values of variables by simply typing 
the "SET" command.  

After running various applications for a while you might 
notice a lot of files in the temp directory that were not
cleaned up.  When you run low on disk space, you might want
to look in the temp directory and delete all the files
found there.

One person I talked to had the TEMP variable pointing to
the C:\DOS directory.  This is a very bad idea.  Temporary
files mixed in with operating system files makes it very
difficult to delete the unneeded temp files without 
disturbing other files.  If the TMP and TEMP variables
point to a special directory that is used ONLY for temp
files, you can delete all the files in that directory
occasionally without fear of wiping out something 
important.

If you turn off the computer while Pasokon TV is running, or
if it hangs or crashes, the temp file might not be deleted.
Do this a few times and a lot of free disk space will 
disappear.


Disk Maintenance
----------------

There are certain tasks you should do occasionally (perhaps
once every few weeks) to keep your disk drive in good shape.

1. Virus Checker.

        Computer viruses are programs that attach themselves
        to other programs, spread to other programs, and often 
        do nasty things to your computer. 

        Commercial products, in the original sealed package, 
        are usually quite safe because the manufacturers are 
        generally very careful about protecting their systems 
        from viruses.  The biggest danger is in free software 
        found on random bulletin boards or other places because 
        you have no idea where it came or what happened to it 
        along the way.  Even if the original was clean, it may 
        have become infected later.
       
        Before installing any new non-commercial software, 
        be sure to check it for viruses.  MS-DOS 6 includes
        a virus checker called MSAV.  You might want to
        purchase another one from a different company.  New
        viruses are being created all the time and it can't
        hurt to have multiple virus checkers that look for
        different types of clues.

2. File System Checker.

        If a program terminates abnormally while writing a file,
        that disk space can disappear.  That's because it was 
        removed from the free space list but not yet associated
        with a particular file.

        If the power is turned off at the wrong time, the disk
        can be left in an inconsistent state.

        MS-DOS 6 includes a program called SCANDISK which 
        examines a file system for problems and fixes them.
        In Windows 95 run it by clicking on the Start button
        and choosing Programs -> Accessories -> System Tools.
        Click on ScanDisk.

        Run this more often if you have problems with
        programs crashing or a power failure which can
        cause file system corruption.

3. Defragmentation.

        On a new disk, all the files are adjacent and all the
        free space is in one big contiguous region.  This is
        good.

        As time goes on, and many files are created and deleted,
        the free space is in little chunks all over the place
        rather than gathered together.  What this means is that
        a new file will have little pieces scattered all over
        the place.  It is much faster to access complete adjacent
        tracks on a disk drive instead of bouncing all the over
        the place for little pieces here and there.

        Performance can be improved by running a defragmentation
        program.  Be sure to run SCANDISK first.  In MS-DOS 6 
        this is called DEFRAG.  In Windows 95, click on the 
        Start button and then choose Programs -> Accessories -> 
        System Tools.  Click on Disk Defragmenter.

