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╔══════════════════════════════════════════════════════════╗ ║ A L P H A ║ ║ A Turbo Pascal ver 6.0 TPU Unit ║ ║ ║ ║ Copyrighted (C) John H. Gohde, 1991 ║ ║ All Rights Reserved ║ ║ ║ ║ ShareWare licensed for trial use only. ║ ╚══════════════════════════════════════════════════════════╝ Page 1 11-02-91 INTRODUCTION ALPHA is a Turbo Pascal version 6.0 Unit that provides support for enhanced COLOR TEXT screen operations. ALPHA provides direct functional replacements for video statements found in the CRT unit. It is the second of four units designed to replace the CRT unit. It also contains over 40 additional new commands, including support for Video Paging or allows redirection with COLOR. It contains something of interest for everyone. ALPHA was designed to make the problem of assuring compatibility with ALL MONO, CGA, EGA and VGA adapters as transparent to the programmer as possible The enclosed ALPHA unit requires Turbo Pascal version 6.0, which is not included. COPYRIGHT NOTICE Both the software and its documentation are copyrighted materials. I reserve all rights to these materials under United States law and international copyright conventions which are not expressly granted to the user. No part of this material may be reproduced or modified in any way without my prior, expressed written permission. This document is NOT Public Domain. It is intended as an informational document for evaluative purposes and for use by Registered users. This Document may be copied in whole for that intent only. DISCLAIMER I EXPRESSLY DISCLAIM ALL WARRANTIES INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF FITNESS FOR A PARTICULAR PURPOSE AND MERCHANTABILITY. YOU USE BOTH THE SOFTWARE AND DOCUMENTATION AT YOUR OWN RISK! TRADEMARKS Turbo Pascal and all other Borland products are trademarks or registered trademarks of Borland International, Inc.. Portions of the enclosed Turbo Pascal unit(s) are Copyrighted (C) 1983,1990 by Borland International as it/they were compiled with Turbo Pascal. Any other brand or products names mentioned in this document are trademarks or registered trademarks of their respective holders. Page 2 11-02-91 SHAREWARE LICENSE GRANT OF LIMITED LICENSE: You may use one copy of this software on a single terminal connected to a single computer for a maximum of 30 days for the sole purpose of determining suitability for your intended use. In other words, I am allowing you to use/test my unit for a thirty day trial period. Use of my unit in any of your personal programs requires registration. Further, commercial use of any of my units requires an additional one time registration fee as a commercial user. SHAREWARE NOTICE ALPHA is NOT public domain software. For continued use of my unit, EVALUATORS must register! This is true ShareWare. This means that what you see is what you get. There is no Registered version! In order to ask for the absolutely lowest donation possible, I am not requesting that you pay for the shipping and handling required by a registered diskette. Hence, ALPHA is fully functional. You are required to purchase a copy of this software for use beyond this 30 day evaluation period. One copy must be purchased for each computer, cpu, terminal, or work station. TEST OF PURCHASE: Possession of this software for more than 30 days or use of this software on more than one computer or use in ANY of your programs renders you liable for the current purchase price for each copy in use or in your possession. NOTICE: I have provided for a way of detecting its use in any TP program!!! HOW TO REGISTER To register simply fill out the attached registration form (REGISTER.FRM) and send it with payment to: John H. Gohde ALPHA P O Box 17581 Richmond, VA 23226 Page 3 11-02-91 BACKGROUND INFORMATION Due to the perceived negative side effects (whether real or imagined) of Borland's CRT Unit, I decided to write a functional replacement. Not having purchased the Run Time Library, I simply started duplicating the various functions in my own unit. It soon became apparent, that the CRT unit actually covered several functional areas. Further, I realized that each area could also be significantly enhanced with features not found in Borland's original unit. Hence, I actually ended up developing a family of units to replace Borland's CRT Unit. This family of units are as follows: WOW, ALPHA, KEY, and MOUSE. The WOW unit provides the miscellaneous functions with minimal overhead. The ALPHA unit offers support for simple non-direct video COLOR TEXT screen operations. The KEY unit offers support for keyboard operations. The MOUSE unit offers support for both two and three button mice. WOW is the first unit of this family, and is required by ALL my other units, even those not related to the CRT unit. The central theme of this family is AlphaNumeric or TEXT programming using no direct video writes and the standard InPut/OutPut functions in a manner that is compatible with multitasking environments. This family approach allows users to pick and chose the specific functions that are actually needed in their programs. As a result, users who do not need all the functions of all the units can minimize program size. (Each unit has a small initialization section.) In addition, Borland's smart linker will remove all unused code and data from your program. Hence, the increased functionality of these units will not increase your program size unless you actually use those functions. This software file contains the ALPHA unit and a copy of the required WOW.TPU unit (WOW is also distributed separately with complete documentation.). (The other units are packaged separately.) It also contains as little source code as possible. This package is intended for those who call themselves Pascal Programmers rather than just a PC user. Page 4 11-02-91 This unit does not use OOPs. All the routines are low level and can be easily incorporated into Objects of your choice. This unit is NOT directly comparable to the CRT unit as it offers a significant number of advanced features, such as auto clean up, which are NOT provided by Borland. ALPHA does NOT offer small size as one of its features. If size is of primary importance then I would suggest using only my WOW unit. SOURCE CODE The source code used in this Unit was written for Turbo Pascal version 6.0+. Extensive use was made of the new built-in assembler. As at least 90% of the low-level code is in the BASM format; support for prior versions of TP would require a major rewrite of the code (not to mention my having to buy a legal copy of same). Hence, I have no plans for supporting prior versions of Turbo Pascal. Currently the source code is not available. Frankly, I would not be able to guarantee at this time a fast response to any software purchases. Any way, I would much rather be developing new code than stuffing envelops!!! Also, if source code was available I would also be asking for a lot more green. Once the total package has been distributed nationally, through several sources, and the companion Windowing Package has been likewise distributed, I will be in a good position to determine if the software design has stabilized, or not. Right now I want to be able to make design changes as needed. Once, I am satisfied on how both packages work together, I will start selling licenses to use the source code( ie, make source code available). In addition, please consider the fact that you are currently using the CRT, DOS, and Printer units without any source code, either. Lack of code hasn't stopped you from using the CRT unit; has it? And, if you spent $190 for the RTL, well you probably would not be interested in ALPHA anyway. Nevertheless, this UNIT is supported by me. (see SUPPORT.DOC). Any bug fixes necessary, will be made available for download / FREQ from my support Bulletin Board. Registered Users are entitled to use future updates to this UNIT necessitated from future versions of Turbo Pascal; at NO additional charge, pursuant to our signed license agreement. Page 5 11-02-91 COLOR AND THE EVILS OF CRT Users of ALPHA might decide that it does not work with color the way CRT does. Actually you are comparing apples with oranges! CRT also does not work with color, once you turn off CRTs so called evils. Or more precisely, those users do not really know how CRT works; or are confused by how color actually functions. (Run, also, the CRTDEMO and DEMO2 programs.) There are two so called features/evils in the CRT unit which some users object to and eventually turn off. ALPHA does not contain these evils so there is nothing to turn off. Also if you are NOT going to use these features, why carry their overhead in your program as required by the CRT unit? In all fairness, these features are evils only in AlphaNumeric, Text, or TUI programming. As these features are required in graphic or GUI programming, there usefulness is relative to the type of programming that you are doing. So if you are primarily interested in graphics, then ALPHA may not be for you. Evil number one is Direct Video. CRT contains a DirectVideo boolean variable. By Default this variable is set to true with CRT. ALPHA does not use this variable. This means that CRT is designed for the WRITE and WRITELN statements to write directly to the screen memory. ALPHA does NOT write directly to video memory. Instead characters are displayed using the standard BIOS output functions. This fact makes ALPHA both slower and compatible with Multitasking. With todays faster CPUs / Video Boards, processing speed is not really as noticeable as it was on the original PC. However, ALPHA provides for paging which is how intelligent programmers can make their programs appear instantaneous using ALPHA. Direct Video writes do not affect color. Because CRT writes directly to video memory it also includes the CheckSnow boolean variable. ALPHA does NOT use this variable because it is not necessary!!! Without direct video updates Snow on CGA adapters is not possible. Hence, your programs need not even check for this condition. The second evil involves I/O redirection of the INPUT and OUTPUT standard text files. With the CRT unit I/O redirection is no longer possible unless the user adds code to explicitly assign back standard input and output. No additional code is needed with ALPHA, since Page 6 11-02-91 ALPHA uses ONLY standard input and output. So users who want output to be redirected using the CRT unit; MUST add extra code which is not required by ALPHA. However, when output is closed with the CRT unit both the WRITELN and WRITE statements no longer work with Color!!! I suggest that you try experimenting with the CRT unit to verify what happens. Don't just take my word for it. Obviously, the same thing happens with ALPHA. So if you want both color and redirection with the CRT unit what option do you have? ALPHA provides for color with the CGA_MODE option and the Echo statements. COLOR You have a choice of 16 colors. But, after studying the subject for a while you should actually STOP thinking in terms of 16 colors. What you have is two versions of only eight colors!!! There are eight colors: 0-7 plus a highlighted version of those same colors. Or you can call them background (0-7) and foreground (highlighted) colors. REDIRECTION vs. Color vs. 16 BACKGROUND COLORS By Default only eight of those 16 colors are available for the background. This allows for blinking. The CRT unit automatically works some magic and enables you to get 8 background colors on a EGA. With ALPHA you can get ALL sixteen background colors (even on a CGA), but by choice only. First of all you have to chose between blinking and 16 background colors. You can not have both at the same time. Next you have to decide how you are going to deal with users using a CGA monitor versus those using Ega/Vga. This package touts itself as being multitasking compatible. The problem is that the CGA can also use 16 background colors but only after a direct hardware write. This may cause some multitasking problems. But, the choice is once again yours (use the MakeAlphaChoice statement). It takes place rather quickly, so it probably wont cause any problems. Page 7 11-02-91 MONOCHROME ADAPTERS If you want your program to function on MONO or MDA adapters than you must either not use video pages or code your program so that it processes video pages in sequence; since MDA adapters only have one video page. With a MDA monitor installed, ALPHA will force all page commands to use the first page. Updating video pages out of sequence will, thus, result in your program jumping around in a manner not intended by you. With a MDA adapter installed all color attributes are filtered by ALPHA to only three values: Normal, Invisible, and Reverse. This will allow color to work on a MDA. However, unless you use more than JUST color in your programs users with MONO monitors will still not be able to see what is going on. So the use of the IBM extended character set Box drawing characters to give some substance to your program screen images; is highly recommended. Programmers also have the option of terminating their program if a MDA is installed with the TerminateOn command. VIDEO ADAPTER MODES BLACK AND WHITE MODE -------------------- There is no Black and White Mode or MONO mode. If this is what you want than you really shouldn't be using ALPHA in your program. My WOW unit will provide for this mode. But, if you prefer to use ALPHA just be sure NOT to use the HighVideo, paging, or any of the other Color statements. DEFAULT CGA_MODE ---------------- The default mode of ALPHA is set up for the CGA adapter. This means eight foreground and eight background colors. Both color and redirection is possible, at the same time. And, Standard OutPut remains open. Page 8 11-02-91 In this mode, any background color values that you code in your program are filtered out at run-time for users with a CGA adapter by subtracting 7 from background color values above seven. For EGA and VGA users these numbers are not filtered, but the user still sees only eight background colors (not 16). If you only want to use 8 background colors then you can use the Set8Color and Change8 commands and have the TP compiler catch background color coding errors. These commands also are faster. EGA_MODE -------- You can put your program in EGA mode by selecting it with the MakeAlphaChoice(EGA_MODE) command (ie, at start up). This means now that EGA users and above can now see 16 background colors while CGA users are still limited to 8 colors. In addition, redirection is no longer possible as standard OutPut has been closed by ALPHA. CGA16_MODE ---------- In this mode all users with a CGA and above adapter can see 16 background colors. This mode is not recommended as it requires a direct memory write and may interfere with some multitasking environments. You would select this mode with the MakeAlphaChoice(Cga16_Mode) command at the start of your program. VGA MODE -------- ALPHA has no VGA mode. However you can first execute TextMode(EgaVga) in your program to get 43 rows on your screen. To get 50 rows follow up with the SetEgaRows(at50) command. These commands ignore all adapters below the EGA. Page 9 11-02-91 WINDOWS ALPHA does not support windows. After releasing the complete CRT replacement package, I will develop a Windowing package that is compatible with ALPHA. But at present it does not exist. No reason why you couldn't write you own Windowing routines, however. But don't confuse windows with pages. They are entirely two different things. Windows take up valuable CPU RAM and Video Pages do not!!! Windows usually cover only part of a screen while a video page always includes the entire screen. PAGES Video Pages use Video Ram which is contained within the video adapter not the system board. Hence it is another way to squeeze extra memory out of a computer. Also, you can use a video page as a means of saving a screen with only marginal programming overhead. Hence, by using Video Pages your program code size can actually be smaller and your program can actually use less user RAM. (However, in multitasking environments your program might end up using CPU RAM.) The Video Paging feature of ALPHA will work in multitasking environments because no direct video writes are made. ALL screen updates are performed with the standard BIOS function calls. ALPHA FILTERING --------------- With a MDA or MONO adapter installed all pages above the first page are filtered out. Therefore, you have to see to two it that you update date the hidden pages in sequence, as MDA users will not have hidden pages. (While a major complication could have been added to ALPHA to simulate video pages for MDA users that would have only added to the overhead burden of CGA and above class users.) With a CGA adapter installed all pages above the fourth page are filtered out by subtracting 4 from pages fifth and above. Page 10 11-02-91 No check is actually made to determine how many Pages an installed adapter is capable of supporting. It is simply assumed that MDA's supports one and CGA's and above support 4 video pages. One uses Video pages as a means to develop screens hidden from a user with the SetPage and PreparePage commands. Once completed they can be flashed instantaneously to a user with the SetActivePage command. Hence you use video pages to speed up the apparent speed of your program, or in lieu of windows. Each of the eight video pages has its own cursor position and cursor shape. However, all the video pages share the same TextAttr variable. PROGRAMMER DECISIONS INSTALLED ADAPTER DECISIONS --------------------------- If your program must terminate if a user is using a certain kind of Video Adapter than use the TerminateOn statement at program start up or write your own termination routine. The following decisions are made by the programmer with the MakeAlphaChoice command. REDIRECTION AND COLOR DECISIONS ------------------------------- Must the program have redirection? A) YES Either you will use just WOW or you will have to select the CGA_MODE option. In addition, you can only use the First Video Page ( ie, don't use any page commands ) with the Echo commands. B) NO Must the program have COLOR? 1. NO Use either just WOW or select CGA_MODE. 2. YES Must the program use 16 background colors? Page 11 11-02-91 A) NO Select the CGA_MODE option and use the Set8Colors and Change8 commands. B) YES Must installed CGA adapters have 16 background colors? 1. NO Select the EGA_MODE option and use the SetColors and Change commands. 2. YES Select the CGA16_MODE option and use the SetColors and Change commands. EXIT PROCEDURE DECISIONS ------------------------ Are you going to write your own Video clean up procedure? A) NO Are you going to write your own Main Program Exit Procedure? (A Main Program Exit Procedure is required to leave a parting comment to your users.) 1. YES Select the No_MainExit Option. 2. NO Code your parting user comments. B) YES Select the No_AlphaExit option. Page 12 11-02-91 TEMPLATE.PAS The attached file called TEMPLATE.PAS contains the suggested format of all programs using ALPHA. I should emphasis, however, that any format may be used, as long as you know what you are doing. ALPHADEMO.PAS The attached file called ALPHADEMO.PAS is a sample program that does not use the CRT unit and illustrates some of the features of ALPHA as well as document how some of new commands are also used. I suggest that you study this program closely. I have verified that it works on MONO, CGA, and VGA adapters, as is. NORMVIDEO - LOWVIDEO - HIGHVIDEO Indiscriminate use of the LowVideo, HighVideo, NormVideo statements and changing program modes in order to high light certain text should be avoided. Text highlighting can be accomplished either with the ReversColorXY or Change color statements. WORKING WITH, NOT AGAINST, ALPHA The reason why you are going to use ALPHA is because you like its potential. The ONLY way for you to realize this potential is for you to work with ALPHA by using its (and not your own) statements. Therefore, you should always use an ALPHA command to update a variable rather than directly updating a variable (ie, TextAttr and LastPage). In addition, you should always use one of the Echo Statements rather than the CRT's WRITE statements. (The CRT uses the RTL library to work some direct video magic to change how the WRITE statement functions. ALPHA does not affect the RTL.) You must also bit the bullet, so to speak, and write a few scratch programs to learn how ALPHA works. Merely, adding ALPHA as just another unit will not guarantee Page 13 11-02-91 you success; if your program contains its own competing statements!!! Using ALPHA means that you will no longer have to write certain routines in your program. So work with ALPHA, and NOT against it by NOT substituting your own procedures. ENUMERATED TYPES CursorShapes = ( OFF, ON, BLOCK); ---------------------------------- The screen cursor on each of the eight video pages can be one of these types. You set the cursor with the CURSOR statement. Pages = ( FIRST,SECOND,THIRD,FOURTH,FIFTH,SIXTH,SEVENTH,EIGHTH ); ----------------------------------------------------------------- This type lists all the permitted video pages. However, using pages FIFTH through EIGHTH is not recommended nor will ALPHA ensure adapter compatibility. Bkgrd = ( Black8, Blue8, Green8, Cyan8, Red8, Magenta8, Brown8, White8); -------------------------------------------- The eight background colors permitted in CGA_MODE. Use them in conjunction with the special Change8 commands. EgaRows = ( at43, at50 ); -------------------------- The row options available on an Ega/Vga adapter in Font8x8 Text mode. AlphaChoices = ( No_AlphaExit, No_MainExit, Cga_Mode, Ega_Mode, Cga16_Mode ); ------------------------------------ These are the ALPHA options available to the programmer. Selections are made with the MakeAlphaChoice command. VideoCards = ( NOCARD, MDA, CGA, EGA, PGA, VGA, MCGA ); ------------------------------------------------------- These are the types of video adapters reported installed by ALPHA. Page 14 11-02-91 CRT VARIABLES SUPPORTED TextAttr: byte; --------------- This variable was provided to maintain compatibility with the CRT unit. While possible to directly alter this variable, it is not recommended. Doing so will result in a program that is incompatible with certain video adapters. There is only one TextAttr that is used by all eight Video Pages. Think of it as a scratch pad that holds the last used Color attribute value. Most statements, but not all, use it as the default color attribute to be displayed to the screen. The Change ,ReverseColorXY, WriteCharOver, and DisplayOver statements ignore it. LastMode: integer; ------------------ This variable was provided to maintain compatibility with the CRT unit. Considering the fact that ALPHA has an Exit Procedure that will restore the original DOS environment and the CRT unit has the NormVideo statement, this variable is of no real value. ADDED PUBLIC VARIABLES LastPage: Pages; ---------------- The last/current hidden page being updated. It is not recommended that you directly update this variable. Access it instead through the SetPage and PreparePage commands. Your program will start out automatically using the first video page. LastProc: Pointer; ------------------ The variable points to the Optional Main Program Exit Procedure. Page 15 11-02-91 CRT FUNCTIONS SUPPORTED Procedure ClrEol; ----------------- Clears row from cursor position to the end of the line. Procedure DelLine; ------------------ Deletes the row under the cursor. Procedure HighVideo; -------------------- Filters the current foreground value of TextAttr so that 8 is add to all foregrounds less than eight. Procedure InsLine; ------------------ Inserts a blank row above the cursor. Procedure LowVideo; ------------------- Turns HighVideo off. Procedure NormVideo; -------------------- Restores the TextAttr variable to the Starting Color Attribute value. Procedure TextBackground( Color: byte); --------------------------------------- Changes the background color value stored in the variable TextAttr. You would use this variable if you were planning to Display a new text value and only wanted to have a different background color. Procedure TextColor( Color: byte); ---------------------------------- Changes the foreground color value stored in the variable TextAttr. You would use this variable if you were planning to Display a new text value and only wanted to have a different foreground color. Page 16 11-02-91 Procedure TextMode( Mode: integer); ----------------------------------- Changes the current textmode. Use the standard CRT text mode constants. Function WhereX: byte; ----------------------- Returns the row position of the cursor. Function WhereY: byte; ----------------------- Returns the column position of the cursor. Page 17 11-02-91 ADDED FUNCTIONS Following the TextAttr method used in the CRT unit, color is selected separately rather than on every command. Likewise, ALPHA uses the same method both for color attributes and for video pages. All commands are in reference to the value of LastPage except for SetActivePage and GetActivePage. Therefore, LastPage must be set to the value of GetActivePage if you want to reference values on the displayed screen. Procedure AltPrintScr; ---------------------- For Ega/Vga adapters it selects an alternate print-screen routine that works properly if the screen length is not 25 rows. The ROM BIOS default print-screen routines always prints 25 lines. Procedure Change8ColorXY( X,Y,Len,Foreground: Byte; Background: Bkgrd); --------------------------------------------------- A special CGA_MODE version of ChangeColor that uses the compiler to catch background color errors. It is also faster. Procedure Change8BackgroundXY( X,Y,Len: byte; Color: Bkgrd); ------------------------------------------------------------ A special CGA_MODE version of ChangeBackgroundXY that uses the compiler to catch background color errors. It is also faster. Procedure ChangeColorXY( X,Y,Len,Foreground, Background: byte); --------------------------------------------------------------- Retains text values but changes both foreground and background color at screen position X,Y for a length of LEN. Procedure ChangeBackgroundXY( X,Y,Len,Color: byte); --------------------------------------------------- Retains text values but changes ONLY background color at screen position X,Y for a length of LEN. Page 18 11-02-91 Procedure ChangeForegroundXY( X,Y,Len,Color: byte); --------------------------------------------------- Retains text values but changes ONLY foreground color at screen position X,Y for a length of LEN. Procedure Cursor( Shape: CursorShapes); --------------------------------------- Turns the cursor ON, OFF, or selects a BLOCK cursor. Procedure Echo( S: string); --------------------------- Displays the string S on the screen at the cursor position while echoing the string to standard output. This command provides for redirection. Procedure EchoLn( S: string); ----------------------------- Displays the string S on the screen at the cursor position while echoing the string to standard output. And, moves the cursor to the beginning position of the following row. This command provides for redirection. Procedure Display( X,Y: byte; S: string); ----------------------------------------- Displays the string S on the screen at position X,Y. Procedure DisplayOver( X,Y: byte; S: string); --------------------------------------------- Displays the S on the screen at position X,Y while using the current screen colors at those positions. Procedure EndofLine; -------------------- Positions cursor on the last column of the current row. Procedure FillPage( Ch: Char); ------------------------------ Fills the screen with character CH. Function GetActivePage: Pages; ------------------------------- Returns the page currently being displayed on screen. Page 19 11-02-91 Function GetBackGround( ColorAttr: byte): byte; ------------------------------------------------ Returns the background color of a color attribute byte. Function GetForeGround( ColorAttr: byte): byte; ------------------------------------------------ Returns the foreground color of a color attribute byte. Procedure GetBoth( var ColorAttr: byte; CH: char); -------------------------------------------------- Enables you to get both the color attribute and the character in one command. Function GetColorAttr: byte; ----------------------------- Returns the color attribute byte at the cursor position. Function GetChar: char; ------------------------ Returns the character at the cursor position. Procedure GotoX( X: byte); -------------------------- Moves cursor to Row X while remaining in the same column. Procedure GotoY( Y: byte); -------------------------- Moves the cursor to Column Y while remaining in the same row. Procedure Home; --------------- Moves the cursor to the starting column while remaining in the same row. Procedure MakeAlphaChoice( Text: TextChoices); ---------------------------------------------- How the programmer can select the various ALPHA options. Page 20 11-02-91 Function MaxCols: byte; ------------------------ Returns the number of columns on the screen. Function MaxRows: byte; ------------------------ Returns the number of rows on the screen. Procedure Prepare8Page( P: Pages;C: CursorShapes; Foreground: byte; Background: Bkgrd); ------------------------------------------------------- A high level routine that performs a number of common procedures. It executes SetPage, Cursor, Set8Color, and Cls using the CRT_MODE special 8 option. Procedure PreparePage( P: Pages;C: CursorShapes; Foreground, Background: byte); ------------------------------------------------------------ A high level routine that performs a number of common procedures. It executes SetPage, Cursor, SetColor, and Cls. Procedure ReverseColorXY( X,Y,Len: byte); ----------------------------------------- Swaps the color attribute value of foreground and background color starting at screen position X,Y for length LEN. It does not change TextAttr. Procedure Set8Color( Foreground: byte; Background: Bkgrd); ---------------------------------------------------------- A special CGA_MODE version of SetColor that uses the compiler to catch background color errors. It is also faster. Procedure SetColor( Foreground, Background: byte); -------------------------------------------------- Changes both the foreground and background colors of the TextAttr. Avoids the need for using TextColor and TextBackground sequentially. Procedure SetActivePage( Num: Pages); ------------------------------------- Displays the video page Num on the screen. Procedure SetBorder( Color: byte); ---------------------------------- Changes the Border color on all CGA, EGA, and VGA monitors. Page 21 11-02-91 Procedure SetEgaLines( Num: VgaRows); ------------------------------------- Sets the Ega scan lines on Ega and above monitors. Procedure SetPage( P: Pages); ----------------------------- Allows you to write to the hidden page P. Use this command instead of directly changing the LastPage Variable as it works with MONO and CGA adapters. MONO adapters are forced to used ONLY the first page and CGA adapters for pages over four have the number 4 subtracted from P. Procedure TerminateOn( V: VideoCards); -------------------------------------- A built in routine that terminates the program if the installed video adapter is equal to V, and displays a message stating that the succeeding VideoCard is required. Function VideoAdapter: VideoCards; ----------------------------------- Returns the installed video adapter. Procedure WhereXY( var X,Y: byte); ---------------------------------- Returns the X,Y screen position of the cursor. Procedure WriteCharOver( Ch: char; Num: word); ---------------------------------------------- Writes the Character CH at the current cursor position Num number of times using the current screen colors at those positions. Page 22 11-02-91 BONUS STRING FUNCTIONS Function Color2Str( Color: byte): str16; ----------------------------------------- Converts a color constant into a color name string. Function Int2Str( Num: longint; Width: byte): str80; ----------------------------------------------------- Converts a whole number into a string of WIDTH length. Function Real2Str( Num: real; Width,Decimals: byte): str80; ------------------------------------------------------------- Converts a real number into a string with Decimals of WIDTH length. Function Pages2Str( P: Pages): str7; ------------------------------------- Converts the enumerated type Pages into a string value. Function VideoAdapter2Str( V: Videocards): Str4; ------------------------------------------------- Converts the VideoCards type into a string value. Page 23 11-02-91 PRODUCT SUPPORT This product is supported by the author via a product support echo on a 24 hour a day BBS. First, time callers may download the latest versions of my products. You can contact me by data phone (8N1 1200/2400 BAUD) at: ╔═══════════════════════════════╗ ║ The FreeBoard BBS ║ ║ (804)744-0744 ║ ║ Richmond, Va. ║ ╚═══════════════════════════════╝ The FreeBoard BBS is a multi-node RBBS-PC board on the Fido Net Work with over 400 MEG's of files. And, of course, you can ask your SYSOP to FREQ this or any other files from this board with the following info: 1:264/212,The_FreeBoard_BBS,Midlothian_VA,Bill_Hunter, 1-804-744-0797,9600,CM,XX,LO,HST The support echo is called LZE-WC. You arrive at this conference from the MAIN menu by joining it as follows: J LZE-WC The author may also be contacted by writing to: JOHN GOHDE ALPHA P O BOX 17581 RICHMOND, VA 23226-7581 If you expect a response, be sure to include a self addressed and stamped return envelop! Page 24 11-02-91 UPDATE HISTORY VERSION 1.00 -- originally released on 11-02-91