                   Diversi-Cache(tm)
                    By Bill Basham
               Copyright 1987 DSR, Inc.
                     Version  1.0
                     INSTRUCTIONS

PLEASE COPY THIS DISK AND GIVE IT TO EVERYONE YOU KNOW!

It is legal to copy and distribute this disk.  However, to legally
use the Diversi-Cache program on this disk, you must send payment
within 2 weeks.  Please send $35 directly to:

 DSR, Inc.
 34880 Bunker Hill
 Farmington, MI 48018-2728

You will receive a user support number, and a new disk with the
latest version of Diversi-Cache.  Your honesty will help us
distribute future programs in this same, low-cost way.

*** Introduction ***

Diversi-Cache requires an Apple //gs with at least 512K, and an Apple
3.5 disk drive.  The Apple //gs comes with 256K, so you must buy a
memory card with at least 256K, which plugs into the //gs memory
expansion slot.  We recommend buying a 1-megabyte (1000K) expansion
card, since Diversi-Cache will use up to 800K.

Diversi-Cache dramatically increases the I/O speed of the Apple Disk
3.5, under any operating system (ProDOS, Pascal, DOS 3.3).
Diversi-Cache only speeds up the Apple Disk 3.5 designed for the
Apple //gs, and will not affect the speed of the older Apple //c
compatible UniDisk 3.5.

Diversi-Cache speeds up the Disk 3.5 in two ways.  First of all,
whenever the system reads a block, Diversi-Cache actually reads an
entire track.  This triples the speed of disk reads, and doubles the
speed of ProDOS writes.

Secondly, Diversi-Cache allows you to allocate a cache memory buffer
from 0 to 800K in size.  An 800K cache works for the entire disk,
while a 400K cache would cache the first 1/2 of the disk, for
example.  Whenever the system reads a block in the cache range,
Diversi-Cache saves it in the cache buffer.  If the system asks for
this block again, it comes out of memory at "Ramdisk" speed.

*** Installing Diversi-Cache ***

The Diversi-Cache program is a binary file named "CACHE".
Diversi-Cache may be installed under ProDOS or DOS 3.3 with:

BRUN CACHE

Diversi-Cache installs itself in the first 64K of the memory
expansion card (bank 2), and stays there permanently until a power
off re-boot.  That is, Diversi-Cache stays installed even if you
reboot with open-apple-ctrl-reset.  Note:  after a reboot,
Diversi-Cache is reconnected with the next toolset call (INPUT or
entering the control panel does a toolset call).

The Diversi-Cache program comes on a 5.25 ProDOS floppy disk.  We
recommend you boot this disk when you power on, to install
Diversi-Cache.  You can then boot from the 3.5 drive with "PR#5".

You can also use the Apple //gs system utility program to transfer
all of the Diversi-Cache files to a newly formatted 3.5 inch disk.

*** Adding Diversi-Cache to PRODOS *** (Not available on demo disk)

You can append Diversi-Cache to any disk with a file named PRODOS,
for automatic installation when you boot that disk.

Choose this option from the menu, and insert the disk you want to 
update.  Then, enter the slot and drive where the disk is located.  
You may enter the slot and drive of a hard disk, if desired.

If the PRODOS file you select already has Diversi-Cache appended, you 
will be given the option to add the new Diversi-Cache, or to remove 
Diversi-Cache and restore PRODOS to normal.

*** Installation Errors ***

When you BRUN CACHE, you will hear a "beep" if the installation was
unsuccessful.  The usual reason for this is that you tried to install
Diversi-Cache again, when it was already installed.  You also get
this error if you don't have a //gs memory expansion card, or if
there is no memory available on bank 2 to install Diversi-Cache.  If
this occurs, try installing Diversi-Cache from a power-off boot.

Note: To avoid the beep, POKE 0,0.  The beep does not occur when you 
append Diversi-Cache to PRODOS.

*** Removing Diversi-Cache ***

You can remove Diversi-Cache by turning the power switch off for 10
seconds or so, but this will eventually wear out the switch.  You can
simulate a power-off re-boot as follows:

1. Hold OPEN-APPLE_SHIFT_CONTROL keys down.
2. Press and release RESET key.
3. Wait for 2 beeps.
4. Release OPEN-APPLE_SHIFT_CONTROL keys.

This will remove Diversi-Cache, and clear your Ramdisk (if any).

Note: If you have added Diversi-Cache to your PRODOS file, it will be 
re-installed when you boot ProDOS.  To avoid this, continue holding 
the OPEN-APPLE_SHIFT_CONTROL keys down, until the ProDOS boot message 
appears on the screen.

*** Changing the Cache Buffer Size ***

The first time you access the Disk 3.5, Diversi-Cache allocates up to
800K for the cache buffer, by calling the Apple //GS memory manager.
If 800K is not available, Diversi-Cache will allocate the largest
possible block of memory.

If you need more memory for a program, you can decrease the size of
the cache buffer by first pressing OPEN-APPLE_CONTROL_ESCAPE.  You
then select "Diversi-Cache" from the "Control Panel" menu.

Hold down the left or right arrow keys to adjust the buffer size.
Press <RETURN> when you see the desired buffer size.  Note that a
buffer size of 0K disables the cache buffer entirely.  Even with the
cache buffer disabled, Diversi-Cache will still approximately triple
the read speed for long files.

*** Changing the Cache Drive ***

If you have more than one Apple Disk 3.5, Diversi-Cache normally will
only cache drive #1.  To select a different drive to cache, hit the
down arrow key after selecting the buffer size as described above.
You may cache drive 1, drive 2, or both drives.

When you cache both drives, the cache buffer is cleared every time
you switch from one drive to the other.

When you BRUN CACHE, you start with an 800K cache for drive #1.  To
change these starting values, RUN SETCACHE on the Diversi-Cache disk.
This modifies and BSAVE's the CACHE file, so be sure your disk is not
write protected.

*** Disabling Diversi-Cache ***

Hit the down arrow again, and then the left arrow to disable
Diversi-Cache entirely.  This may allow you to use Diversi-Cache with
protected disks, by temporarily disabling it when the program checks
for a protected block.

*** Compatibility  Problems ***

Diversi-Cache works with any program which uses the //gs expanded
memory correctly, as well as most copy protected programs.  However, 
some of Apple's initial system software has memory management bugs.
In particular, if you set up a Ramdisk with the control panel, be 
sure the maximum and minimum size are the same.

                       WARNING!!!!!!

THE MAXIMUM AND MINIMUM SIZE OF YOUR //GS RAMDISK MUST BE THE SAME!

Diversi-Cache tends to trigger bugs in software which occur when the 
//gs memory fills, since the cache buffer fills all available memory. 
In particular, the //gs Ramdisk may return write errors if memory is 
full and the minimum size is set to less than the maximum.  Many 
programs, such as Appleworks, don't check for write errors on a 
ramdisk, and may do strange things (like destroy your disks, even).

Other problems occur with ProDOS16 version 1.0, which de-allocates 
all memory.  This will eventually destroy your Ramdisk space and 
Diversi-Cache as other programs overwrite their memory.  If you have 
to boot Version 1.0, be sure to do an "open-apple_shift_ctrl_reset"
reboot afterwards.

Some ProDOS16 programs "hang" when they run out of memory.  These 
programs will work if you reduce the cache size, or increase the
amount of memory in your //gs.

Hopefully, ProDOS16 version 1.2 corrects these problems.  It is
contained on the //gs system disk with the version number 2.0.

An occasional program, such as "Bard's Tale", ignores the //gs memory
manager and destroys all memory, overwriting Diversi-Cache, Ramdisk,
and anything else.  You will have to run these programs from a power
off reboot.

In summary, if a program doesn't work with Diversi-Cache, try 
reducing your cache size.  If possible, set your Ramdisk size to 0 to 
leave more memory for Diversi-Cache.

*** Converting to a System File ***

You can convert Diversi-Cache to a system file, so you can run it
directly from a menu selection program.  To do this, first run
BASIC.SYSTEM.  Then CATALOG the Diversi-Cache disk and note the
length of the CACHE file.  Then, enter the following:

CREATE SCACHE,TSYS
BLOAD CACHE
BSAVE SCACHE,TSYS,A$2000,Lxxxxx   (where xxxxx is length of CACHE file)

*** Converting to DOS 3.3 ***

First, boot DOS 3.3 and format a disk with:

INIT HELLO

Then, boot ProDOS again and enter:

BLOAD CACHE
Put in your new DOS 3.3 formatted disk
PR#6
BSAVE CACHE,A$2000,Lxxxxx (where xxxxx is length of CACHE file).

Note that to run DOS 3.3 on a Disk 3.5, you need a DOS 3.3 adapter
program.  We recommend AmDOS(tm) from Gary Little, 131 Water St.
#210, Vancouver, B.C., CANADA V6B 4M3, 604-681-3371 for $20.

AmDOS works with our Diversi-DOS(tm).  For maximum DOS 3.3
performance on the Apple Disk 3.5, combine Diversi-Cache,
Diversi-DOS, and AmDOS together.

*** Licensing Information ***

Although Diversi-Cache is copyrighted, DSR allows copying and
distribution of the program subject to the following restrictions:

1.  Anyone receiving a copy of Diversi-Cache must send a $35 license
fee directly to DSR, Inc.  within 2 weeks.

2.  Any company, club, or individual may charge up to $5.00 for
distributing copies of Diversi-Cache, provided it is clear that an
additional $35 fee must be sent directly to DSR.

Publishers:

Publishers may license Diversi-Cache for a $250, one-time fee for all
their programs.  To do this, the following message must appear in the
written documentation:

  This disk contains a high-speed operating system called
  Diversi-Cache(tm), which is licensed for use with this program only.
  To legally use Diversi-Cache with other programs, you may send $35
  directly to:  DSR, Inc., 34880 Bunker Hill, Farmington, MI 48018.
  You will receive the latest Diversi-Cache program disk with
  documentation.

Multiple Computers:

Each additional computer license fee is $35, up to a maximum of $250
for all the computers owned by a company (or school district).

*** User Support ***

Your user support number entitles you to talk directly to the
programmer, Bill Basham.  Please write if possible, or call:

313 553-9460 between 3 and 5 PM Eastern time.

*** Diversi-Copy ***

Diversi-Copy(tm) is the fastest and easiest way to make back-up
copies of your 3.5 disks.  Diversi-Cache triples the disk read speed
when used with Diversi-Copy.  Note, however, that Diversi-Copy exits
with a power-off type reboot, so you'll need to re-install
Diversi-Cache.

Diversi-Copy was chosen as inCider magazine's "Editors' Choice".  It
is the best copy program available, for both 5.25 and 3.25 drive
copying.

*** Diversi-Key ***

Diversi-Key is a keyboard macro program for the Apple //GS that will
work with any program that allows interrupts.  This includes programs
that run under Pascal, ProDOS, or DOS 3.3.  Diversi-Key works with
Appleworks 2.0, as well as most other programs.

Diversi-Key sends macro keystrokes as if you had typed them at the
keyboard, so you don't need to modify your programs to work with
Diversi-Key.  Diversi-Key allows you to add an almost unlimited
number of custom functions to any program.

Diversi-Key includes a flexible way to program the mouse to work with
any program, as well as date and time macros, nested macro calls,
nested repeat, IF, and WHILE conditional loops, and much much more.

*** How to Order ***

To order, please send your check to:

DSR, Inc.
34880 Bunker Hill
Farmington, MI 48018-2728

The cost of our programs is as follows:

Diversi-DOS     $30
Diversi-Copy    $30
Diversi-Cache   $35
Diversi-Key     $45

We only sell our programs by mail-order, and will notify you of
future program updates which you may purchase for $5 each.

