Classic Computer Magazine Archive CREATIVE COMPUTING VOL. 11, NO. 4 / APRIL 1985 / PAGE 42

Concurrent PC Dos; when integration isn't enough. (evaluation) Chris Terry.

Integration of several functions in one software package is a concept that has more than come into its own during the past year. Many popular "integrated packages" allow you to insert figures from their spreadsheet and database members into reports and letters prepared on their word processing members. But what if you need a more powerful word processor than an integrated package offers, or what if you want to include figures from an engineering program in your spreadsheet?

In those cases and many others like them, you must change concepts. You abandon "integration" and adopt "concurrency" or "multitasking." You look for a system that will let you run the programs of your choice "concurrently"--which is exactly what Concurrent PC DOS from Digital Research is designed to do.

Concurrent PC DOS is a multiuser, multitasking system that allows you to run up to four PC DOS or CP/M programs simultaneously. It can be used by one or two users, one who uses an IBM PC keyboard and display and a second who uses a dumb terminal connected via the serial port. Hardware Requirements

The minimum hardware requirements are 256K of memory and two floppy disk drives. This configuration is sufficient to get the system up and running, and perhaps to run a single application program that is not too memory-hungry. However, it is quite inadequate to take advantage of the windowing capabilities or to use the multitasking feature.

DRI recommends at least 512K of memory, one or two floppy disk drives, and a hard disk; a hard disk configuration needs at least 1.2Mb of space, partitioned for CP/M.

The operating system occupies 150K, and each application program (window) starts at 64K; this brings the count to 406K when running four programs simultaneously. However, some care must be taken in allocating memory, since some programs (such as word processors and spreadsheets) claim all available memory for use as data buffers. Installation

Installation of Concurrent PC DOS on a system with two floppy disks, or on an XT, is straightforward, and the instructions in the manual are clear.

If you have an XT, it is recommended that you back up all files on the hard disk, since you may have to reformat it with both a PC DOS and a CP/M partition. If your hard disk is an add-on (such as Tecmar or Tallgrass) you may encounter even more complications, since the hard disk installation program will not run unless the appropriate disk drivers are available to it. If you are not thoroughly familiar with the technical details of your system, you will need expert help for this type of installation. Windows

You can simultaneously run programs in each of the four possible windows, although there are a few restrictions. You cannot, for example, run more than one program that uses BasicA. And, although you can reduce window size to display two, or even three, windows simultaneously, the useful of this feature depends upon whether the application programs will support it. Many applications, not designed for multitasking, bypass the operating system during screen updates and may try to write over the full screen, spilling into other windows. The DRI applications, however, are designed for multitasking and do not create this problem. Utilities

Several system utilities are provided with Concurrent. FDMAINT and HDMAINT are formatters for use with floppy and hard disks, respectively; HDMAINT also allows the establishment of both a CP/M and a PC DOS partition on the hard disk. Another utility preempts part of main memory for use as a RAM disk, although the usefulness of this depends on how many windows you normally use at one time. It will speed things up if no more than two programs art to run simultaneously, but even 640K would hardly be enough for four programs and the RAM disk.

A really useful utility allows you to define up to 50 function keys for each window; it is somewhat like the CP/M-80 utilities SmartKey and MagicKey in that a single keystroke can represent an entire string.

The PRINTMGR print manager utility allows you to define a printer for each window, and provides print queuing of up to 255 files. It can be activated interactively from a menu or by command-line entries. One valuable feature is that for each window you can specify the number of copies to be printed, the printer to be used, and standard formatting parameters.

Three application programs are provided with the system: an editor, a communications package, and a simple database. Editor

DR EDIX is a full-screen editor that supersedes the infamous ED and PC DOS EDLIN (which is nearly as bad as ED). DR EDIX creates straight ASCII files with a carriage return/line feed at the end of each; lines may be up to 255 characters long and are numbered by DR EDIX internally, the current line number being displayed at the bottom right of the screen. DR EDIX allows you to work with four different files at once, each in its own buffer; a marked block of text can be moved within the same buffer or to one of the other buffers, to allow calling up boilerplate material.

The cursor can be moved left or right by character, word, or line, and up or down a line at a time. A scroll command moves the cursor up or down one page. Insert and overtype modes are both provided, and global find/replaced commands are also available.

DR EDIX is not in any sense a word processor, but is a clean, simple editor for writing source code or simple letters and memos. Communications

DR TALK is a versatile communications package containing all the features generally needed in communicating with other computers or bulletin boards and time-sharing services. It can upload and download both ASCII and binary files, using either its own protocol or the XMODEM (Christensen) protocol. For use with manframes and commercial services, the pacing feature is extremely valuable. This feature sends ASCII files a line at a time, waiting either for a fixed time or until a prompt is received from the remote station.

A dialing directory can hold up to 60 names and phone numbers; each entry specifies the paramters to be used when communicating with the station. Database

I did not have an opportunity to exercise CARDFILE, but it is a simple name/address/phone/comment database similar to a card file. Searching for a name is linear, either displaying all cards in sequence, or going directly to the required name. Conclusion

Concurrent PC DOS is easy to use, considering its power, and is flexible in that it can run both CP/M-86 programs and PC DOS programs. The menus are excellent, because they give you enough information to do exactly what you want, yet don't hold up the expert user and infuriate him by making him go through several levels of menu. Besides, the real expert can always escape from the menu system altogether and work entirely at the system level with its cryptic prompts and complex command lines. But for the novice, or the person who only rarely uses some of the features, the menu system has one enormous advantage: at any time you can call up on-line help files to clarify details of the current operations available.

In performance, Concurrent is as fast as PC DOS and on a hard disk system is not noticeably slowed by running more than one program. The only trouble is that many applications are just not designed for multitasking systems and may not work well together. I have no doubt, however, that with the advent of more multiuser, multitasking systems such as IBM AT, many of the bestselling application programs will be updated to remedy the incompatibilities.

Products: Concurrent PC Dos (computer program)