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COMPUTER BITS BY DARREN YATES Visual BASIC for DOS provides Windows-like user interfaces The Visual BASIC package includes two large manuals – one a programmer’s guide & the other a command reference manual. The program also supports an extensive on-line help system. Designed to replace Quick BASIC 4.5, this DOS version of the popular Windows program will run all QB4.5 & DOS’s QBasic programs & allows you to produce Windowslike user interfaces. But is it that much of an improvement? Visual BASIC has certainly renewed interest in a language which many purists (read “C programmers”) had previously dis­ missed as a toy. It’s certainly now the easiest way to create Windows programs that run, look and feel just like those expen­sive big-company applications. However, reading through the reference manual and looking at all the financial commands that are available, you quickly get the feeling that it was designed mainly with the economist in mind. The lack of almost all hardware control commands certainly hasn’t endeared it to those of us who like to plug bits and pieces into the back of our PCs. Many of you have read our “Computer Bits” series where we have made use of Quick BASIC 4.5. Although it may be a good language and used by many small businesses, Microsoft’s decision to no longer support it probably means that its life span is coming to an end. Or is it? We recently upgraded our software to the new Visual BASIC for DOS in the hope that it would contain enough hardware control commands to make it worthwhile. All over the packaging, they make the claim that it will run all QBasic and QuickBASIC 4.5 pro­ grams. In fact, if you look through the November 1994  77 The programming environment displays the code editor as soon as you boot up. It has quite a few similarities to the old QuickBASIC 4.5. The menu box on the right is used to change between the code & form editors. monochrome monitors with no graphics facility, we can only hazard a guess that this may be the reason why text-only screen windows are available. For a language created in 1992, this does seem a bit archaic, particu­larly when you consider that the soon-to-be released Windows 4 won’t even run on a 286 machine, let alone on an XT! Memory requirements are at least 640Kb of RAM but it will support XMS (extended) and EMS (expanded) memory if your PC has it – sort of. So long as you’re prepared to run your application from the programming environment – that is, from within Visual BASIC – you’ll be able to use the upper memory. However, if you prefer to run compiled applications from the DOS prompt, then you’re stuck with the 640Kb limit. In this respect, it hardly seems much of an improvement on QB4.5. Of course, by running DOS 5 or later, you can push most of DOS into the upper memory area and have around 600Kb left for your application. That said, we would have thought that it would­n’t have been too hard to incorporate E/XMS driver support in the compiler. The pluses? The code here is for CALC.FRM, a basic function calculator. This comes with VB for DOS & gives you an idea on how to program using this system. By clicking on the up arrow, you can make the code editor full screen size. manuals, the QB4.5 com­mand set is actually a subset of VB for DOS. This thankfully means that all QB4.5 programs can remain alive for some time yet. And more importantly for those of us who like to “tinker” and play around with our PCs, it means that all of the QuickBASIC hardware control commands have been retained in their past for­mat. However, if that’s the case, what are the new features in this Visual BASIC for DOS? Well, its main selling point is its ability to create a DOS version of the Windows user interface with command buttons, dialog boxes, directory listings and the like. While these can make it much easier for a user to run programs, the 78  Silicon Chip interface is designed to run from the text screen only – so you can’t produce any fancy graphics or company logos. This is disappointing but more on this later. Hardware requirements One of the reasons for this is probably due to the fact that VB for DOS will run on any 8088-based PC. Note that it won’t run on an 8086 machine. If you want VB to run on your old XT, you’ll have to open the lid and have a peek inside to see which processor you have. What you need to look for is a 40-pin dual in-line (DIL) IC. It will either be marked 8086 or 8088. If it’s an 8086, then you’re out of luck. As many, if not most, XTs used Well, one thing that no one can take away from Visual Basic for DOS is its mouse control command support. Now you can add mouse support to all your programs by simply adding in the appropriate commands. You don’t need to know anything about the mouse hardware or interrupts. This is one feature that everyone will agree was badly needed on QB4.5. The manuals, although a bit confusing at times (aren’t they all!), have been split into two 650-page plus volumes – one a programmer’s guide and the other a command reference man­ual. The programmer’s guide contains all the peripheral information such as converting programs from QB4.5 to VB and describes how to produce a Windows-like interface. It also includes a compatibili­ty chart between VB for DOS and Windows, Quick­BASIC, QBasic and even the old GW-BASIC. The reference manual contains detailed information on each command, as well as programming examples for most of the com­mands. Most of this is also found in the on-line help system The complier is said to be more efficient in creating code which means that your programs will run faster. One good thing they suggest is that you can load your QuickBASIC programs into Visual BASIC, compile them and they’ll run just the same as before, only faster. Product support The form editor is where your graphic screens are designed. You are limited to block graphics which is disappointing but it allows all PCs to use your programs. The menu box on the left allows you add a variety of tools, including command buttons, directory boxes and ASCII graphics. This window shows you the possible subroutines which can be modified in the code editor. The numbers to the right of each subroutine are the sizes to the nearest kilobyte, while the “cmd” before each subroutine indicates that it is based on a command button response. which will tell you almost all that you need to know. How is it to use? If you’re used to QuickBASIC 4.5 and its programming envi­ ronment, then it won’t take you too much time to get used to the new format of VB. As we mentioned in the VB for Windows review, programming is now based on what is called “object oriented programming” or OOP. Instead of writing your programs in the conventional manner, you have to take into consideration what the user could be doing. If you have a series of command buttons appearing on the screen for example, you must consider that any one of those buttons could be activated and you have to write code to handle that. When programming, you’ll find yourself swapping between the user interface editor and the programming editor. The user inter­face editor allows you to create screens called “forms” which the user will see. These are created using a process that’s similar to using a desktop publishing program. You click and drag out marques to indicate the size of the item you wish to put on the screen, whether it is a command button or a dialog box. In this respect, it is very similar to the Windows version. We had a few questions to ask Microsoft on how some aspects of the language worked. So we decided to ring up the product support division of Microsoft, just as an ordinary customer would, to get some help. After ploughing through their infuriating phone system, we were told we’d be charged $35 for each call made. When pressed, we were told that “product support is not included in the purchase price of most Microsoft products”. Come on Microsoft, can’t we have just one call? The other alternative is to look at some of the computer books from companies such as Que Corporation and others. They have produced quite a few good books on both the DOS and Windows version of VB. If you desperately need to use EMS or XMS memory in your compiled programs, you will require the professional version of Visual BASIC. With this version, you also get the ability to produce compiled code which is optimised for either 286 or 386 processors but at $765 RRP, or more than twice the cost of the standard version, the price seems a little steep. Conclusion If you have an investment in Quick BASIC and you’re looking for the upto-date product, then Visual BASIC for DOS is it. But if you don’t need to create a Windows-like interface, then you may be better off sticking with what you’ve got. We also feel that it could have been made to do a whole lot more. Had they included the option of having the windows operate in VGA mode, it would have been almost ideal and a huge leap above QuickBASIC 4.5. Instead, it’s more of an upgrade for Quick­BASIC rather than a “whole new programming system”. At the time of writing, the recommended retail price of Visual Basic for DOS is $295 but don’t expect to get any support for that price – support SC costs extra. November 1994  79