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Better Ram utilization for 80286 systems.

Better Ram Utilization for 80286 Systems

It's time computers demanded that their owners possess the capability of thinking. In this world of planned obsolescence, old computers do not have to go to the scrap pile. In the June issue (see p.6), I discussed how my XT became an AT after an hour or so at Computer Advance Systems (Scarborough, Ont.). A number of members have taken advantage of this option and done the same; others think the AT is dead and this is a backward step. Just look at the glossy advertisements for 386SX-,386-and 486-based machines. IBM is the world leader; what has it done? They brought out a whole new series of computers, based upon the 80286.

There is a lot of life left in 80286 technology. Its biggest negative is the DOS 640k barrier. I was really impressed when I upgraded my old Dragon-32 computer to a massive 64k. Today, some popular programs such as Lotus version 3.0 and Excel won't even consider running with 640k. After my system upgrade, I had 1 meg of RAM. It was annoying to learn that no software recognized extended RAM. The only thing to do was create a 384k RAM disk. For this review, I added another meg of RAM and set out to find a ways utilize it. This gave me 2,048k in the 80286 protected mode split between 640k for DOS and 1,408k of extended RAM.

My first attempt to use this RAM for any useful purpose was based upon a software solution. A number of memory management programs will allow extended memory to simulate expanded memory. I tried a few. Although Lotus recognized the expanded memory and had more space available for larger spreadsheets, I couldn't believe the snail's pace with which the Allways screen was drawn. Simulating expanded memory may work, but very slowly. Following this effort, I tried two practical approaches, one based upon software; the other upon hardware.


Headroom provides a software-based access into extended RAM. I use four TSR (terminate and stay resident) programs which do a number of simple jobs: dialing the telephone or capturing graphics. These eat up close to 50k of RAM and sometimes interact with each other or the programs in use. With Headroom, they can be loaded into extended RAM or for that matter, left on the hard disk. When needed, left on the hard disk. When needed, into action then store them away again until next needed. They don't show on the directory as they are not taking up conventional RAM. Although you have freed up this RAM for TSR storage, there is a penalty; Headroom consumes 53k for itself, about the same as my TSRs, but those few TSRs barely scratch the capacity of this program. It can swap up to 32 megs of software. This means you can load WordPerfect and Lotus and ... a few more and with a simple keystroke move one in and the other out, ie. multi-tasking. It was easy to swap programs back and forth between disk and RAM and even faster between extended and conventional RAM. Headroom can work with extended or expanded memory ... or from the hard disk. To operate Headroom you need a path command in your AUTOEXEC.BAT file and a batch file to load your applications; these are prepared during the initial setup. The manual was extensive. Of particular interest was Chapter 3: "For people who don't read the documentation". Operation was simple and, once set up, there was really nothing to do other than just go ahead as though it wasn't there.

All Chargecard

For the most effective use of extended RAM, All Computers (Toronto) has introduced a card about the size of a credit card. In fact this little piece of Canadian technology is called an All Chargecard due to its credit-card size and the way it charges up the old 80286 to do things it was never intended to do. You simply pull your 80286 chip out, plug it into the chargecard and plug the chargecard in its place. Installation is simple, but perhaps frightening when you realize that you have to dig in and remove the entire brainpower of the system and that this single chip costs $100 plus ... and can be destroyed if you damage a single pin. All provides a tool to remove the chip and a variety of sockets that will fit anything but one of those rare systems where the 80286 is soldered rather than in a socket.

By remapping the routes the 80286 uses to access memory, the Chargecard takes full control of extended memory and treats it as LIMS 4.0 expanded memory. It also provides access into the reserved region above the 640k barrier. You need to add the ALLEMM4.SYS driver to your CONFIG.SYS file and make some modifications to the AUTOEXEC.BAT File. The difficulty here is a manual written in computerize. (A new one is being prepared now.) When I first tried it, my RAM disk kept locking the system up. All's technical services department suggested I run the information program ALLMENU and upload the file to the company's computer bulletin board (BBS). The next morning they had the solution. My RAM disk had been configured for extended memory from the pre-All days. The /E option had to be switched to a /A for expanded RAM. The use of the BBS provided an interesting 1990 approach to troubleshooting.

With Hercules graphics, I now have 704k available for DOS. TSR programs are in high RAM and it's nice to have them loaded and still have close to 640k available. With Lotus, the Allways screen is drawn quickly indicating fast access to the expanded memory. The WordPerfect /R startup option loads WP.FIL into expanded RAM to provide faster operation ... and in the process consumes almost 1 Meg of RAM, about 384k in conventional and 650k in expanded.

Where a straight software solution to RAM cram may utilize extended memory, it often consumes a good chunk of RAM doing so. The Chargecard requires only 12k, but opens up more than an order of magnitude in return. Files, buffers, TSRs, network drivers, etc. can be loaded into high RAM to free up as much as 200k for programs. Today's programs are getting bigger; that space is becoming important.
COPYRIGHT 1991 Chemical Institute of Canada
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1991 Gale, Cengage Learning. All rights reserved.

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Title Annotation:Chemputing
Author:Silbert, Marvin
Publication:Canadian Chemical News
Article Type:Product/Service Evaluation
Date:Jan 1, 1991
Previous Article:Statistical Quality Control, 6th ed.
Next Article:Montreal scientists are the tops.

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