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1985-12-09
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TVMSYM -- A virtual memory system for Symphony Release 1.1
------ - ------- ------ ------ --- -------- ------- ---
TVMSYM.COM is a utility program that sets up a 640K virtual memory
system for Symphony Release 1.1. It gives Symphony 1.1 640K of expanded
memory without the installation of an expanded memory board. Instead, the
system's fixed disk (or RAM disk) is used for expanded memory data
storage.
Because TVMSYM physically moves banks of data to and from the disk
(or RAM disk), Symphony 1.1's operation will be slower under TVMSYM than
if an expanded memory board were installed.
TVMSYM.COM and this document file may be freely copied and
distributed, and are intended as a demonstration of a virtual memory
system. If Symphony runs your application under TVMSYM with acceptable
speed, you may want to consider ordering Micro VMS, a full-featured
program with some advantages and enhancements over TVMSYM. Ordering
information is included at the end of this document.
Questions or suggestions can be directed to Bill Gordon [76010,3466].
How to Get Going
--- -- --- -----
To use TVMSYM, you will need Symphony Release 1.1 and an IBM PC/XT/AT
(or compatible) computer with 640K of memory already installed, a fixed
disk, and DOS 2.1 or higher. You can use TVMSYM with a RAM disk, such as
the AST Advantage! board running under VDISK or the JRAM-2 board running
under JETDRIVE. Operation of TVMSYM with a RAM disk will be much faster
than with the fixed disk in your computer.
To run TVMSYM:
1) Download the TVMSYM.COM file and copy it into the fixed disk sub-
directory containing your Symphony 1.1 program files. The
ACCESS.COM, SYMPHONY.COM (or SYMPHONY.EXE if you have used COPY II PC
Version 2.5 to install Symphony), and SYMPHONY.CMP files should be in
this subdirectory.
2) Make sure you have at least 640K of free space on your fixed disk, or
RAM disk (if used).
3) Put your Symphony 1.1 key disk in Drive A: (if your system requires
its use).
4) Make current the subdirectory containing your Symphony 1.1 program
files and TVMSYM.COM.
5) Type in
TVMSYM [/d]
(followed by a carriage return) at the DOS prompt, where "/d" is a
slash followed by an optional drive letter indicating the disk drive
or RAM disk "drive" that you would like TVMSYM to use for its data
storage. Note that there must be at least 640K of free space on the
specified drive. If you would like TVMSYM to use your default drive,
do not enter anything after "TVMSYM".
TVMSYM will set up its required disk (or RAM disk) files, and will
load and run Symphony. When you Exit Symphony, TVMSYM will erase the
files it created for its own use and return control of the system to you.
Some Background Information
---- ---------- -----------
Because it supports the Lotus/Intel/Microsoft Expanded Memory
Specification, Symphony Release 1.1 can address up to 4 Megabytes of
"expanded memory", over and above the 640K of conventional memory
available in the IBM PC/XT/AT line of computers. A number of expanded
memory boards designed to this specification, such as the Intel Above
Board and the AST RAMpage board, have recently appeared on the market.
SYSCOMP's Micro VMS program allows Symphony 1.1 to address up to 4
Megabytes of "virtual memory" WITHOUT the use of expanded memory boards.
Instead, it uses the computer's fixed disk (or RAMdisk, if available) to
store data that would normally be stored in an expanded memory board.
Virtual memory refers to memory that really isn't present, but is
simulated by a fixed disk or other device. Symphony 1.1 allows only 64K
of expanded memory to be "switched in" at any one time, the rest is stored
in deactivated banks on the expanded memory board(s). Micro VMS uses the
fixed disk (or boards like the JRAM-2 or the Advantage!) to hold the data
that is not currently switched in.
The actual bank switching process with an expanded memory board is
very fast. The Intel Above board takes less than 1/2000 second to switch
in a new bank of memory. The operation of Micro VMS is slower due to the
disk read and write operations. Even using the JRAM-2 or the Advantage!
board, blocks of memory are moved from one location to another during a
bank switch, so more time is needed.
Although the actual bank switching time using Micro VMS is much
slower than the switching time on expanded memory boards, Symphony 1.1's
overall performance with TVMSYM is better than might be expected, because
Symphony 1.1 performs most operations with a minimal number of bank
switches.
The Conventional Memory Problem
--- ------------ ------ -------
It is possible to get the Symphony "Memory Full" error even if you
have lots of expanded memory still free.
Symphony 1.1 uses the expanded memory for data and the conventional
memory for pointers to that data. In some cases, the "pointer memory"
fills up before the "data memory" does.
Loading any memory resident programs (like Sidekick or SuperKey)
before running TVMSYM, or any DOS add-in programs when Symphony is
running, will aggravate the conventional memory problem. If you run out
of conventional memory, try temporarily removing any memory resident
programs or detaching any DOS add-ins that you have attached.
TVMSYM itself requires about 70K of conventional memory. The
full-featured Micro VMS program, although more powerful, actually uses
LESS conventional memory.
Some Tips on Faster Operation with TVMSYM
---- ---- -- ------ --------- ---- ------
1) Set your Recalculation Method to "Manual". This is very important
when running a large application under TVMSYM. Any operation that
requires a memory "bank switch" will be slower with TVMSYM than it
would be with an expanded memory board involved. Keep your
recalculations to a minimum.
2) Keep your Recalculation Order set to "Natural".
3) DON'T try to sort a large database while running under TVMSYM.
Database sorts require a large number of "bank switches". If you
work much with databases, we suggest the use of our dB III Import/
Export programs, which will allow your database processing to be done
with the powerful dBASE III database program.
A sample 8,000 record name and address database containing 9 fields
required over 530,000 bank switches to sort. The XT/Above Board
performed this sort in about 12 minutes. The same sort on the
AT/Advantage! system (we didn't time it) would take about 2 days!
Remember, ANY large spreadsheet will take a while to Recalculate. If
you have an application that is particularly slow running under TVMSYM, it
may not be that much faster with an expanded memory board installed.
If you are using a physical disk with TVMSYM, and if you see the disk
LED stay on or come on repeatedly during an operation, then you probably
CAN save some time by installing an expanded memory board. On the
average, you will save about 1/2 second per disk access if you install an
expanded memory board.
Micro VMS -- Who Needs It?
----- --- --- ----- --
Micro VMS will probably appeal to those who:
1) have a little more time than money,
2) don't have any free slots in their computer, but need some expanded
memory for Symphony 1.1,
3) only have one or two applications that require more memory than
Symphony's conventional memory provides, or
4) have already purchased the JRAM-2 or Advantage! board (or other
board than can operate as a RAM disk outside the 640K of
conventional memory), and would like to use this board for Symphony
1.1 expanded memory.
How to Order Micro VMS
--- -- ----- ----- ---
If your application runs satisfactorily under TVMSYM but you need
more expanded "memory", you may want to order Micro VMS. Micro VMS is
SYSCOMP's full-featured virtual memory system for Symphony 1.1. It allows
you to set up as much as 4 Megabytes of virtual memory for Symphony 1.1
or 1-2-3 Release 2.0. It will also allow other programs which support the
Lotus/Intel/Microsoft Expanded Memory Specification to use its virtual
memory.
Micro VMS uses less conventional memory than does TVMSYM, and is
installed slightly differently. It also loads faster.
As a registered user of Micro VMS, you will be eligible for technical
support and upgrades as we continue to improve Micro VMS's performance.
To order Micro VMS, just call SYSCOMP at 619-277-0400. Micro VMS is
normally in stock, and can be shipped the same day we receive your call.
The price is $75 plus shipping, and quantity discounts are available. We
can charge your VISA or Master Card, or we can ship UPS C.O.D.
Feedback
--------
We'd appreciate your comments and suggestions on TVMSYM. Just call
SYSCOMP's technical support at 619-277-0400 or write us at:
SYSCOMP
Technical Support
8825 Aero Drive (Suite 210)
San Diego, CA 92123