This week

REM 'Letter from the Editor
PRINT 'Blast vs Dash
LOOP 'Wetspot 2 Review
PRINT 'Svga Series: Part I

REM 'Letter from the Editor

By ZKman

Hey! Welcome to issue 1 of QBnews. 3 days before today, I didn't know HTML and had no articles. Since then, I created and posted this whole page, plus we got contributions from 2 distinguished members of the QB community in 19day and Aaron Severn. Aaron sent me a 7000 word document on SVGA, which he wrote in one day! Look to next issue for part 2 of his series. Also, next issue, we will feature the Blast! FAQ written by 19day. It's better than the tutorials that come with Blast! and will have you using this rippin' sub set in no time. Next issue will also include a special report on "How the Web saved Qbasic". Hopefully, we will have many more articles than just those.

If you're interested in submitting an article, on anything QB, just look here for how. We need articles! I may not be able to answer your email until late august cuz my computer will be down. Next issue will launch early september, and future issues will be every two weeks. If you email me, I promise to get back to you as soon as I can.

Finally, check out the Visionaries Exchange which will eventually be a complete listing of all QB development companies, although only 3 are represented right now. Again, go here for information on how to submit to the Visionaries Exchange. Happy reading!

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PRINT 'Blast vs. Dash

By 19day
BLAST! - by Andrew L. Ayers
DASH - by Danny Gump

This is a brief FAQ looking over some of the differences and similarities between Blast and Dash. This is not a decision maker document, do not simply read this and decide one is better than the other, because there are differences, some of them quite substantial. Do not after this, decide only to use one thing, and not the other. Decide for yourself.

Part 1: Sprite Handling.

Blast -- Can Get and Put on a screen or offscreen buffer.
Dash -- Can only Get from the screen, but can put on screen and buffer.

Blast -- You can define the invisible color.
Dash -- always 0.

Blast -- Can only put things off the buffer or screen at a limited extent without crashing.
Dash -- Will clip if necessary.

Blast -- Has BlastCls.
Dash -- VSFill is virtually the same thing.

Blast -- no sprite scaling.
Dash -- does it nicely.

Blast -- could Bpset a point on screen or buffer.
Dash -- only screen.

Blast -- Has ability to do lines starting from anywhere to anywhere, but not boxes.
Dash -- Has ability to make boxes, but only straight lines horizontally or vertically.

Part 2: Text

Blast -- has normal, solid color text.
Dash -- Can use gradient 2 colors together, and had a shadowfont.

Blast -- Can print the text to a buffer.
Dash -- Cannot.

Part 3: Special effects.

Blast -- has no faders, palette manipulators of any kind.
Dash -- does. But some of it is easily replicated.

Blast -- has no mouse support.
Dash -- does, but it's easy to get elsewhere.

Part 4: Others

Blast -- came with many different demos and explained how each of them worked.
Dash -- Has demo's with sufficient explanation.

Blast -- has support for QB1.1
Dash -- doesn't

Blast -- could be ran all by itself.
Dash -- Needs to use a QLB, but it does have the QB.QLB in it, so no problem.

Blast -- Could easily crash your computer if you used it improperly.
Dash -- Well, know I know better, don't I.

Blast -- Ucase quite easy to understand once you get the hang of it and constant.
Dash -- Some of the functions are spread apart and arguments are arraned differently from sub to sub. Price to pay for a variation of functions.

Blast -- goes as fast a Blast can go. Better than normal &HA000
Dash -- does go faster on some computers.

  • Danny, 38%
  • Mine, 25%
  • Someone I know, 2%

So what should you use?

Well, it's a tough call.
If it's any indication, I'm using Blast for my scrolling engine for my RPG, and Dash for the battle engine.
Blast seems more in tune with graphical handling of all sorts, but little spunk.
Dash seems more in tune with effects and such, but falls short, just a bit, on aspects of Blast that I needed and was used to.
But dash is ever evolving, and Danny will make Dash whatever the programmer needs it to be, so this FAQ is not over. He is currently planning to write an SVGA lib for Dash, which would really leap over Blast in a big way, although, I hate SVGA, but that's just me.
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LOOP 'Wetspot 2 Review

By ZKman

Wetspot 2, an arcade-style game released by Angelo Mottola of Enhanced Creations is the best QBasic game released...ever. There is nothing that even comes close to this masterpiece completed at this time. From the stunning logo at the start of the game to the fireworks blasting in the hall of fame, this game is polished like no other. If you don't have it, get it as soon as can. It's available at neozones productions or directly from the Enhanced Programming site.

In W2, you are a red crab or, in 2 player mode, red and blue crabs, on a mission to get revenge! The object is to walk your crab around the levels and push blocks into the enemies, of which there are many, all very different. From the easy macaroni worms who simply walk around blindly to the bees who chase you and the penguins who throw snowballs at you, there's a lot of variation. If you played Wetspot original, it's easy to see the difference in enemy design as well as the toughness of the enemies; they're much speedier than in Wetspot I.

If you push a block into a wall or another block, the block dissapears and sometimes a power-up is left in its place. Some are simple, just giving you points; others like the stairway will let you automatically beat the level. You can also get power-ups when you kill enemies, but the power-ups don't tend to be as good as the ones that come from the blocks.

Wetspot's level design is very good, even a little too hard. Area 4 is a section called "The castle of Illusions" where the pushable blocks and the non-pushable blocks look exactly the same! Just when you think you have that ghost trapped in a corner, it turns out you can't push the block! The art changes from area to area as well, and all of the art is better quality than many of the QBtiles.

One of the best things about wetspot 2 is its customizability. There is a level editor you can download to make your own levels. Hundreds of levels created by fans can be found throughout the internet, although I've found none of them are as polished as the original and all of them are extremely hard, with bad designs like high-level enemies in level one. Also, there is an object editor created by Wafn that lets you edit the objects in W2, although the version I downloaded wouldn't start :-(

Wetspot 2 does have some faults, though. I've listened to the .mid's that come with Wetspot and they all sound very good. However, W2 uses QMIDI3.0, a sound player incompatible with some Sound Blasters. It would have been nice if an option was included to use QMIDI2.0 which didn't use the SBSIM driver and works on all computers. Also, some of the levels are very hard! After hundreds of games I've still not beaten W2. Although, the first few levels are easy enough that players won't get discouraged into not playing. But be forewarned, once you get past Areas 2 and 3, you're in for some much meaner Wetspot. Finally, the first release had some bugs. I found one in the hall of fame positions and have heard there are others. The new version (1.3) has fixed these bugs, however.

There are still some things left to be waited for when, and if, a Wetspot 3 is released; most notably, modem play. Playing W3 over a modem would rule! Link up with a friend and you'll be crushing bees all day! Also, it would be cool if W3 had enemies that tried to kill you be pushing blocks into you! That could be like bosses at the end of an area. In conclusion, if you don't have Wetspot 2, get it.
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SVGA Part 1

By Aaron Severn

(this is some very advanced stuff. If you’re a newbie to coding, I suggest you try some less advanced stuff.-ed)

1 Introduction

1.1 What is SVGA

For a long time PC graphics were limited to a small 64 kilobyte piece of memory, and for a long time this was fine. No one needed more than 16 colours and low resolution, and even if they did computers weren't fast enough to handle it. But we all know what happens next. To fulfill the demand for better graphics the VGA was introduced. With 256k of memory now possible and up to 256 colours in one mode it satisfied a lot of people. But that barely quenched our thirst for good graphics, so something more had to be done.

Thus Super VGA came in to existence allowing multiple megabytes of video memory, screen modes with resolutions as high as 1600x1200 and as many as 16.8 million colours. What more could one ask for. Unfortunately, SVGA graphics cards came out by the dozens, each with their own method of use. A program that used SVGA graphics would need to have dozens of different graphics routines to do the same thing on different cards. Something had to be done to end the confusion, which brings us to the next section.

1.2 What is VESA


VESA (Video Electronics Standards Association) was put together to create a standard method for using SVGA graphics. They came up with a VGA BIOS extension that handles the details of various SVGA cards so that you don't have to. It supplies a standardized set of screen modes listed in appendix B that are used in the same way on all cards. At this point in time I can say that most PCs around today have VESA compatible graphics cards, thus it is safe to write software for VESA SVGA rather than for individual cards. That is what this document will discuss.

1.3 Background Knowledge


Before I can start discussing the details of programming VESA SVGA, there's a few things you should be familiar with first. I don't intend to teach these things, I will give only an overview. If you are already familiar with the topics, by all means, skip them.

1.3.1 The Hexadecimal number system


I have found a lot of confusion among QBasic programmers as far as hexadecimal (hex) is concerned. There is nothing special about it, it is just another was of counting. Our decimal number system is base 10, that is, one digit can have 10 different values. Hex is a base 16 system where one digit can have 16 different values. It's nothing special, if we had 8 fingers on each hand we'd all be very familiar with it, too bad we have 5.

QBasic represents hex numbers with the &H prefix, this document will use the same method. Many of you may have seen this in programs and wondered what it meant, well now you know. The following is a small table of hex numbers with their decimal equivalent so you can see what I'm talking about.

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

0 1 2 3 4 5 6 7 8 9 A B C D E F 10 11 12 13 14 15 16 17

The reason we use hex is because it makes a lot more sense with respect to computers. We've all heard that computers are based on the binary (base 2) number system because they are made up of electrical switches which can be either on or off, because of this it is much more useful to have a number system based on a power of 2 (like 16). Any hardware programming will be easier with hex, SVGA is no exception.



If you are using QBasic 1.1, you can ignore this section because you can't use CALL INTERRUPT, but in QuickBasic it is a very handy command to know. What is does is generate an interrupt (named interrupt because the CPU interrupts whatever it was doing to perform the required task) that will do various things for you. It would help to have knowledge of CPU registers when using this command since that is what you are manipulating, but it is not necessary.

The first thing you need is a user defined variable type. This is defined in the QB.BI header file but I will list it here anyway.

    TYPE RegType

When using CALL INTERRUPT, you will create a variable of the above type (DIM Regs AS RegType) and assign values to the pseudo-registers. What values you give depends on what you want to do. There are hundreds of BIOS calls that you can perform and the documentation for each one will give you the details. After assigning the proper values you then use CALL INTERRUPT (or CALL INTERRUPTX if you need the DS and ES registers) to generate the proper interrupt. The format for CALL INTERRUPT is as follows.

    CALL INTERRUPT (interruptNumber, inRegs, outRegs)

InterruptNumber defines which interrupt you want executed (the VGA is interrupt &H10), inRegs is a variable of type RegType which you pass to the function with the required information stored in it, and outRegs is another variable of type RegType which you pass to the function to be filled by it. It returns error info or other things that the interrupt was supposed to return.

1.3.3 Assembly language


This is something this document definitely will not teach. Learning assembly language can be a long and tedious process and there are plenty of tutorials available on the internet to help you out. This is not one of them. If you are using QBasic 1.1, you won't be able to do any of this without knowledge of assembly language. If you are using QuickBasic you can do all the SVGA programming you want without assembly code, however it will never be fast enough for most practical purposes. Thus, I recommend that you learn some basic assembly before you do too much with this document.

1.4 Use in QBasic compared to QuickBasic


As explained above, in order to use SVGA in QBasic 1.1 you must know how to program in assembly language and you must know how to incorporate that code into your QBasic programs with the CALL ABSOLUTE function. In QuickBasic, everything can be done (and a lot should be done) with the CALL INTERRUPT command. However, in order to obtain enough speed to get any practical use out of this knowledge, you will need assembly code. A very fast put routine for 256 colour modes is included in appendix D, it is fast enough for practical purposes, feel free to use it or learn from it.


2 Setting Up

2.1 VESA function calls


VESA has defined function calls in what they call the VGA BIOS Extension. That is, the functions are simply an extension of the standard set of VGA BIOS functions. So you call them the same way you would any other VGA BIOS function, with interrupt &H10. All VESA function calls are prefixed with &H4F, you can have a look at them in appendix C.

2.2 Detecting the VESA


The first thing you have to do to use VESA SVGA graphics is make sure that the computer can handle it. This is done by calling VESA function &H00. If the VESA is present then it will return &H4F in AX and will fill an array with info on the VESA. The following variable type is used.

    TYPE VgaInfoBlock
        VESASignature AS STRING * 4
        VESAVersion AS INTEGER
        OEMStringPtr AS LONG
        Capabilities AS STRING * 4
        VideoModePtr AS LONG
        TotalMemory AS INTEGER
        Reserved AS STRING * 236

For full details on what each field means see appendix A. None of them are important for the basic VESA SVGA program.

Anyway, here is what you have to do to detect the VESA. Sample code will be provided in Part III.

  1. DIM a variable of type VgaInfoBlock defined above.
  2. Set AX to &H4F00, VESA function &H00
  3. Set ES to the segment address of the VgaInfoBlock variable.
  4. Set DI to the offset address of the VgaInfoBlock variable.
  5. Generate interrupt &H10, make sure you use CALL INTERRUPTX because ES is used.
  6. Check the value returned in AX, if it is &H4F, the VESA is present, any other value and it is not.

2.3 Setting a screen mode


Once you have confirmed the presence of VESA support, the next step is to set a mode. For a list of VESA defined screen modes see appendix B. The set SVGA mode function is function &H02. You will also need to run function &H01 to return info on the mode. Like function &H00 it will fill a variable with info, this time on the screen mode. The following is the type definition for the info returned by function &H01.

    TYPE ModeInfoBlock
        ModeAttributes AS INTEGER
        WinAAttributes AS STRING * 1
        WinBAttributes AS STRING * 1
        WinGranularity AS INTEGER
        WinSize AS INTEGER
        WinASegment AS INTEGER
        WinBSegment AS INTEGER
        WinFuncPtr AS LONG
        BytesPerScanLine AS INTEGER
        XResolution AS INTEGER
        YResolution AS INTEGER
        XCharSize AS STRING * 1
        YCharSize AS STRING * 1
        NumberOfPlanes AS STRING * 1
        BitsPerPixel AS STRING * 1
        NumberOfBanks AS STRING * 1
        MemoryModel AS STRING * 1
        BankSize AS STRING * 1
        NumberOfImagePages AS STRING * 1
        Rsvd AS STRING * 1
        RedMaskSize AS STRING * 1
        RedFieldPosition AS STRING * 1
        GreenMaskSize AS STRING * 1
        GreenFieldPosition AS STRING * 1
        BlueMaskSize AS STRING * 1
        BlueFieldPosition AS STRING * 1
        RsvdMaskSize AS STRING * 1
        DirectColorModeInfo AS STRING * 1
        Reserved AS STRING * 216

For a complete description of what everything is, wait for Part III of this series. The important fields are as follows.

  • ModeAttributes - will let you know if the mode is available or not
  • WinGranularity - either 4 or 64, this defines the size of the banks in the mode, more on this later.
  • WinASegment - the start segment of the graphics buffer, usually &HA000
  • XResolution - speaks for itself
  • YResolution - what do you think?
  • BitsPerPixel - how many bits are required for one pixel, useful in determining how many colours are available colours = 2 ^ BitsPerPixel
  • NumberOfImagePages - the number of video memory pages available in the mode, this changes from computer to computer depending on how much video memory is available. This value is actually the number of pages minus 1.

So, anyway, when setting an SVGA screen mode, the following should be done. Again, sample code will be available in part III.

  1. DIM a variable of type ModeInfoBlock.
  2. Set AX to &H4F01, VESA function &H01.
  3. Set CX to the mode number (listed in appendix B).
  4. Set ES to the segment address of the ModeInfoBlock variable.
  5. Set DI to the offset address of the ModeInfoBlock variable.
  6. Generate interrupt &H10, remember to use CALL INTERRUPTX for ES.
  7. Check (ModeAttributes AND 1), this should be 0.
  8. Set AX to &H4F02, VESA function &H02.
  9. Set BX to the mode number.
  10. Generate interrupt &H10.
  11. Check the value returned in AX, it should be &H4F.

I can always be reached by posting a message on the www board at my website, the address is Also go there for more demo code on using SVGA in QuickBasic as well as many other useful routines and fun games.

Appendix G - Works Cited


Super VGA BIOS Extension, Standard #VS911022, October 22, 1991, Document Version 1.0, VBE Version 1.2.

(this is a 3 part document. All code references from appendices will be included in Part III- ed)

That’s all for this time. Next issue, we’ll look at stuff like bank switching and what ports you can use to get a set resolution and number of colors, as well as page flipping.

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Next Issue

Hopefully, next issue will be out by early september, cuz I'm on vacation. In the future new issues will come out every 2 weeks and hopefully we'll have more articles than we have now. Submit articles for next issue now, whatever you want. Hopefully, we'll have some useful stuff then. Also, link to us. If you need a banner, just email me. Thanx for reading!

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