This program gives you a ramdisk between 64K and 768K, and will stay in
memory through screen resolution changes, and even system reset! The
ramdisk code and data is placed at the top of memory, and the screen is
moved down below it. The top of memory pointers are set below the ramdisk
driver, which should keep it safe from everything short of powering down.
The ramdisk install is actually a 2 step process. The 1st time the
program is run, it will adjust memory pointers and set-up the ramdisk
driver. It then exits through the system reset vector so that TOS can
adjust to the new memory size. The 2nd time through, the driver will
be installed and ready to use. The easiest way to accomplish this, is
simply put the ramdisk.prg into an AUTO folder. That way both passes are
automatically performed, in other words, it will auto-boot with no user
interaction. The ramdisk installs as drive D, and if you save the desktop
after you install drive D, then the boot process will be completely automatic.
The ramdisk size defaults to 192K, (512K for the 1 Meg version) but can be
changed by holding down key combinations of the Right and Left Shift,
Control, and Alternate keys. Configurations are as follows:
R. Shift 64K
L. Shift 128K
R. & L. Shifts 192K
Cntl 256K
Cntl & R. Shift 320K
Cntl & L. Shift 384K
Cntl & R. & L. Shifts 448K
Alt 512K
Alt & R. Shift 576K
Alt & L. Shift 640K
Alt & R. & L. Shifts 704K
Alt & Cntl 768K
I realize this may seem combersome at first, but it has the advantage of not
having to wait for a size input during boot-up, and since you will probably
only use a couple of different sizes, it should become very simple.
One note about memory configuration... Since the AUTO folder is loaded
before the desktop accessories, it is possible to configure a ramdisk too
large, leaving less than 128K of memory for other programs. Therefore, if
your disk has many desk accessories on it, you should be carefull to load a
small enough ramdisk so that 128K will be left at the end of the boot.
I wrote this program mainly for programmers that use ramdisks, but have
troubles with system lock-ups and loose everything on the ramdisk. You
can also do faster modem transfers to ramdisk without worrying about the
program crashing on exit. If the system does crash, put a disk with the
ramdisk program in the AUTO folder in drive A, and push the system reset
button. The ramdisk and all its contents will still be there! If the
ramdisk program is not in an AUTO folder, you will have to re-execute it
after system reset.
Enjoy! John Harris