Dr. OPS (Operating Systems) From Cheap Tricks, Nov 94 Issue Published By: Shu Associates, Inc. 120 Trenton St., Melrose, MA 02176-3714 (617)662-0020 (FAX Same) eshu@world.std.com

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Using DataCAD in Windows
by Curtis B. Wayne

Editors Note: Here we expand our definition of DOS to mean all Disk Operating Systems, not just MS-DOS. And we welcome to our stage, Curtis Wayne of Wayne Architects who tells us about using DataCAD under the OS/2 operating system -- a subject that many of you have asked about.

"I feel the need for speed."
Wouldn't it be great to be able to have two or three different DataCAD drawings running at once so you could compare alternative versions of a design? And wouldn't it be great to speed up your machine's performance with DataCAD without having to mess with QEMM, and the many variations of your AUTOEXEC.BAT and CONFIG.SYS files?

We do all this by running under OS/2 - the lesser used "concurrent application" operating system - which is much like Windows but better.

You've probably read the ads: "Better DOS than DOS," and "Operate at a higher level . . ." We find that, in fact, OS/2 is better for running most of the DOS business software we've accumulated over the years as well as being a superb "platform" for DataCAD.

In OS/2, you create an icon on the "desktop" to launch each session of DataCAD. Each session can have different EMS settings, but if you want to have different paths (for different screen resolutions, for example) you'll have to copy DataCAD's configuration and *.exe files to a new subdirectory and call RUNDCAD.BAT from that file.

Decisions, decisions. . .
You can configure OS/2 to offer you the choice of either a pure DOS machine or OS/2 machine at initial boot-up via the "Boot Manager". This requires you to reformat your drive to provide separate "logical" drives for OS/2 and DOS (parts of your drive that act as if they were separate physical drives.) This is not so bad if you are starting out with a "virgin" machine - and not at all pleasant if you already have lots of data on a gigabyte-sized drive.

We partition our drives as "C:" for DOS; "D:" for 0S/2; and "E:" for data and applications.

What's in it for you - the DataCAD user?
We frequently run two, sometimes three simultaneous DataCAD sessions in "virtual DOS" sessions. Each independent DataCAD session remains intact and separate, as if each was on its own computer linked by a very, very fast network to share layer files with the other sessions.

To copy information from one drawing to another is a matter of saving the data to a layer file, popping to the session where the information is needed, and copying in that layer. This saves, depending on the speed of your hard disk, five minutes or more, closing and re-opening different drawings to accomplish the same task.

When presenting to clients, we will run a Quick Shaded view, flip to another session where an alternative scheme is running - shade the same view but with the alternatives, go to yet another version, shade it, and so on. We can compare changes extremely easily this way in the near-virtual reality world of Quick Shade.

As for speed, we get up to 32 memory pages (per the MemCheck function in Directory.) OS/2 creates a separate 640K DOS environment for each DOS session you run. The mouse driver sits "outside" your DOS session.

DataCAD runs faster, period. Disk caching is very fast, expanded and extended memory can easily be set to however much or little you need in each session's "DOS settings".

Why not Windows NT or Chicago or '95 . . . ?
The high end Windows platforms need much, much more memory than you probably have on your machine. If you've got the basic 8MB of RAM shipped with Windows-equipped machines, you should be able to run at least three sessions of DataCAD in OS/2, each set to provide ample expanded memory for quick shade, without any performance degradation. (That's when the mouse starts moving like molasses.)

If you've got Windows, now you can add OS/2 for Windows for a very cheap price. (Something like $49.)

If your world is still only DOS, you will like knowing that when you get OS/2 you also get Windows 3.1, which 0S/2 contains (under an agreement dating to well before the IBM v. Gates divorce.) A new addition to OS/2 also makes Windows 3.21 available.

Caveat emptor
In OS/2, some of your other favorite DOS applications may not be very happy. For example: we send our plotting to a local service bureau via modem. The software we use to do that, as well as most of our other DOS-based communications software, does not behave well in OS/2. But then, Windows communications programs will usually bring your computer to a slow grind when they run in the background (if they run at all.) Communications with pure 0S/2 applications is fine, though.

You will find that when running certain DOS programs in the background, your cursor will get that molasses touch. (Our wordprocessor does this, for example.) These programs do weird things like trying to grab control of all the video memory, access all the COMM ports, and so on. Just don't run them all the time in the background and DataCAD will be cool.

The most annoying limitation of the current release of OS/2 (Version 2.11) is that it will not support background operation of a high-resolution graphics program such as DataCAD (specifically anything requiring higher than 340 x 200 pixels,) So when you switch to another DataCAD session, or to, say, your spreadsheet, the session you are leaving "goes to sleep." So, no hidden line removal in the background and no plotting in background.

You will also find the "Shell to DOS" feature found in DataCAD's File I/O menu leaves you without any mouse or keyboard control. Typing exit + enter returns you to normality. OS/2 sessions (including your DataCAD virtual DOS session) shell to the OS/2 de top by switching sessions, not from within each session. This means that some of the future functions planned for DataCAD 6 won't work under OS/2. There's always the Boot Manager for pure DOS - back to one thing at a time.

If you shift from one DataCAD session to another application while the disk is reading or saving, you risk a fatal error crash. This, however, is not a great problem because your swap file can be renamed from File.SWP to File.DC5 moved to your drawing directory after blowing off or renaming the last saved version of the file. Your last action before the crash won't be saved, but you will have a more complete file than the last .ASV version. Files recovered in this manner remain uncorrupted.

Those of you who want to try OS/2 should find a software aficionado (i.e. "nerd" or paid consultant) to install it. It's worth the couple of hours you'll have to pay or swap services for. Your time is better spent doing what you do best, which we hope is architecture. Although OS/2 is available on CD-ROM, which makes everything faster (one disk instead of 18!) installation is fun only for the masochists among us.

We love working this way. If you took away our OS/2 and made us go back to plain 'ol DOS, or yeeeech Windows, we would be very unhappy campers.

If there are other adventurers out there with DataCAD in OS/2 experience, we'd like to compare notes. Feel free to call us at (203) 869-6691.

Editor's Note: Some of the limitations noted above were to have been addressed by the New Warp release of OS/2, which unfortunately has hit some severe bugs and its release date originally scheduled for this month [Nov '94] has been put off (just a "little bit" says IBM.) Still reports of serious problems with Warp still abound, so we would advise waiting a bit until some of these issues get resolved.

REPRINT OF ARTICLE FROM CHEAP TRICKS, NOVEMBER 1994
Published by Shu Associates

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