Classic Computer Magazine Archive CREATIVE COMPUTING VOL. 9, NO. 12 / DECEMBER 1983 / PAGE 82

Memory-Shift. (sharing data in a microcomputer system) (evaluation) Dan Robinson.


Memory/Shift is one of those simple, why-didn't-I-think-of-that ideas that has the potential to make an impact on microcomputing like a meteor on the moon. The program uses the memory capacity of the IBM PC to hold as many as nine programs at the same time and pass data among them. It turns your software into a word processing/spread sheet/database management/and-anything-else super program.

Memory/Shift partitions the PC memory and operates each segment as if it were a separate computer. Each chamber can hold a program and you can jump from one to another and back again. If you wish, you may take data with you by marking it on the screen and then inserting it in another segment just as if it came from the keyboard.

Columns of VisiCalc numbers, for example, can be inserted in WordStar documents; or you can move to a Basic program for some fast calculations without disrupting your accounting system. You can put a program like dBaseII in one partition and a training program for it in another for quick and easy learning. A communications program can be kept on standby in one segment, ready to go on-line at any time and to pass data to or from an active program.

The hair-tearing that comes from a DISK FULL message after a long work session is gone with Memory/Shift. You can jump to another partition and use DOS to look for space on another disk, kill files to make room for your data, or even format a new disk.

Dividing Memory

It might seem as though you would drop your baton trying to orchestrate as many as nine programs at a time, but Memory/Shift makes sure you will never miss a beat.

When you enter a partition, a message identifying the partition number and its size appears at the bottom of the display together with the logged-on drive for the segment. Each partition can have its own foreground, background, and border colors for easy recognition like a flag on a pole. If you have both the monochrome and color monitor cards installed and two displays, you can set up programs using both screens.

You can begin each partition with its own AUTOEXEC.BAT file or call a program from DOS. Each disk must have a volume ID label, and if the correct disk is not in the active drive you are prompted to insert it. Although you can override the prompt, the process keeps you from getting lost and messing up your files: you won't try to read your WordStar file from the SuperCalc disk or vice versa.

Each partition must be large enough to accommodate the program as if it were running on its own, complete with DOS. If you try to load a program which requires more than the memory which has been allocated to the partition, you are warned and the loading is aborted without crossing the boundary into another segment. Once each program is up and running in its partition, you can rotate from one segment to the next or jump directly to any one of them.

Moving Data

Being able to leave WordStar for a moment to look up something in dBaseII, check a number in VisiCalc, or go to DOS for a few chores is nice. But the real magic of Memory/Shift lies in being able to move data from one application program to another.

When you want to copy something to another program, you simply mark the data on the screen, go to the program to receive it, and dump it wherever you wish. You mark blocks of data on the screen by using the Alternate and large + key on the right of the keyboard. A blinking cursor appears, together with brief instructions to move the cursor to the upper left of your target data and mark it by striking the spacebar.

You then move the cursor to the lower right of the block to complete the marking. Your identified block is highlighted and Memory/Shift asks for the character used as a line terminator, such as a carriage return. You may then move to another segment and dump the block wherever you wish with the Alternate and--keys.

The data you mark can replace that in the Memory/Shift buffer or can be tacked onto it. As many as 3200 characters may be transferred at a time. Character blocks can be composed of an entire screen of data or portions of numerous screens. You can even mix sources from separate partitions.

I have crammed my IBM PC with 640K of RAM and like to divvy up the space with 320K for electronic disk, 64K each for print spooling, word processing, spreadsheet, and communications, and the rest for miscellaneous DOS chores.

Memory/Shift had followed a keep-it-simple strategy, and its brief Help file may be called from any segment. It shows the partition and memory allocation and permits you to change screen colors for the segment. Like all of the Memory/Shift messages, it borrows only a bit of screen space and restores the screen when its job is done.

The standard CTL/ALT/DEL sequence will reboot only the current partition without affecting programs operating in other segments. There is a command for rebooting the entire computer, but Memory/Shift properly treats this as akin to a Freudian death wish and provides an are-you-sure-you-really-want-to-do-this prompt.

Custom Installation

Memory/Shift has a custom installation program which allows you to set the number of partitions and their sizes, their screen attributes, and whether disk label checking will be active. The installation program also allows you to redesignate the keys Memory/Shift uses to move from one partition to another, to mark, and to move data. You can override the settings when calling Memory/Shift, specifying the number and size of each partition.

Memory/Shift will work with DOS 1.1 or 2.0, but as a protected disk it can't be stored on a hard drive. Once the program has been fired up, the disk need no longer be in a drive. One backup copy may be obtained at a nominal charge.

Not every program can live happily ever after with Memory/Shift. Some programs which change the keyboard or disk service routines will cause Memory/Shift to hang or crash, so it is best to check out each program before beginning serious work.

But Memory/Shift will let you hold a handful of programs in your IBM at the same time, move freely from one to another, and take any data you like along with you.

Until lately, the strength of 16-bit computers and their huge memory capacity was only a latent power; and giants like the IBM PC were constrained by their 8-bit style software. Programs like Memory/Shift which integrate major software have changed all that. The giant has been set free.

Products: North American Business Systems Memory-Shift (computer program)