Using The ANSI Driver
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Revision as of 01:23, 23 July 2019 by Netfreak (Created page with "<pre> USING THE ANSI DRIVER by C. Scot Giles...")
USING THE ANSI DRIVER by C. Scot Giles 875 Lake Street Oak Park, Illinois 60301 This essay is an attempt to explain how I use the ANSI.SYS driver to configure the function keys on my computer, and to control the screen. I have used these techniques on my PC and AT for years, and find them to be convenient and effective. ANSI is not widely used by microcomputer fans because the documentation supplied by IBM on how to send control codes to the ANSI driver is among the most cryptic ever produced by IBM. I learned them by reading computer magazines, and slowly figured out how it could be done. I am not a professional computer programmer (indeed I am a clergyman), so some of my technical observations might be in error. But everything here works, and I have retested it before finishing this essay. This essay covers only IBM Personal Computers (PC, XT or AT) running DOS 2.n or greater. I have no experience with compatibles, so you are on your own if you try to use these techniques on one. LOADING THE ANSI DRIVER In order to use any of the techniques in this essay, you must first have loaded the ANSI.SYS driver into your computer's memory using your CONFIG.SYS file. You do this my adding the line, DEVICE=ANSI.SYS somewhere in the CONFIG.SYS file and rebooting your computer. KEYBOARD REASSIGNMENT WITH ANSI Before we get to specific ways to send control codes to the (now loaded) ANSI driver, you must first know what those codes mean. For the function keys the codes are listed on the chart below which first appeared in SOFTALK magazine. Each function key is assigned an "extended function code" which DOS will use to recognize that a function key has been pressed and in what shifted mode, if any. Each number is expressed as a 0 followed by a semi-colon, then the number from the chart below. KEY NORMAL SHIFT CONTROL ALT F1 59 84 94 104 F2 60 85 95 105 F3 61 86 96 106 F4 62 87 97 107 F5 63 88 98 108 F6 64 89 99 109 F7 65 90 100 110 F8 66 91 101 111 F9 67 92 102 112 F10 68 93 103 113 Accordingly, the way to designate the F5 key would be 0;63 while the F10 key would be designated by 0;68 or 0;113 if shifted with the ALT key. If you examine the DOS Technical Reference Manual (not the Technical Manual for PC hardware), you will find a section on SCREEN/KEYS. This section was contained in the DOS 2.0 documentation, but IBM removed it in later editions. Here is a summary of its contents relative to keyboard redefinition. To change one key to have the meaning of another, enter: ESC [#;#p where the first # is the ASCII value of the key being changed and the second # is the ASCII value of the new definition. For example, "A" has the ASCII value of 65 and "Q" has the value of 81. So: ESC [65;81p will result in "A" being redefined as "Q." It is also possible to redefine a key to have the meaning of a string of characters. This is done by enclosing the string in quotes. So: ESC [65;"Hi there"p would change the "A" key to have the meaning of "Hi there." If the first value for the first # is a 0 however, DOS knows that what is being changed is not an ASCII value but the meaning of an extended function code. So if you were to enter: ESC [0;68;"Hi there"p DOS would know to change the meaning of the function key (in this case F10) to the sting enclosed in quotes. This is the key to redefining your function keys to perform much used commands: like DIR, CHKDSK, COPY *.* B: etc. or to load programs from disk. There is a final trick here. If you end the escape command sequence with the characters ";13p" instead of just "p" the command will self-execute, just as if you pressed the [enter] key. The IBM documentation tells the user to preface each command by an ESC command, and I have represented this in the above paragraphs by writing the characters "ESC." at the start of each control code sequence mentioned. Most users assume that this means to press the ESC key on the keyboard when entering the commands. Not so. To get the Escape Sequence to the ANSI driver you must enter it using a prompt command or write a .COM file. For example to configure the F1 key (extended function code 59) to have the meaning in DOS of "autoexec" with an [enter] command at the end of it you cannot type: ESC [0;59;"autoexec";13p as the ESC will not be recognized by DOS as an escape sequence. What DOS will recognize as an escape sequence is the characters "$e" although this surely looks strange at first. Users familiar with the PROMPT command will notice that the "$" character is what the PROMPT command uses as an escape sequence, and that is precisely how we will get the redefinition to be recognized by DOS. If you enter the following command: PROMPT $e[0;59;"autoexec";13p you will see that it works perfectly. You now have the secret to redefining the function keys in DOS. Simply write and run a batch file with a list of PROMPT commands and you will have done it. One precaution, ECHO must be ON, otherwise DOS will suppress the PROMPT command and the escape sequences will not get through. As an example, let's create a batch file called KEYON.BAT that will set F1 as EDITOR [enter], F2 as PC-FILE [enter], F3 as PC-CALC [enter], F4 as PC-GRAPH [enter], F5 as PC-TALK [enter], F6 as PC-WRITE [enter], F7 as BASICA [enter], F8 as DIR without the [enter], F9 to run a batch file called MENUOFF.BAT [enter] and F10 to run a batch file called MENUON.BAT [enter]. It would be as follows: echo on PROMPT $e[0;59;"EDITOR";13p PROMPT $e[0;60;"PC-FILE";13p PROMPT $e[0;61;"PC-CALC";13p PROMPT $e[0;62;"PC-GRAPH";13p PROMPT $e[0;63;"PC-TALK";13p PROMPT $e[0;64;"PC-WRITE";13p PROMPT $e[0;65;"BASICA";13p PROMPT $e[0;66;"DIR"p PROMPT $e[0;67;"MENUOFF";13p PROMPT $e[0;68;"MENUON";13p prompt cls You would also want to create another file called KEYOFF.BAT which resets the function key definitions to DOS normal. The format would be: echo on PROMPT $e[0;59;0;59p PROMPT $e[0;60;0;60p PROMPT $e[0;61;0;61p PROMPT $e[0;62;0;62p PROMPT $e[0;63;0;63p PROMPT $e[0;64;0;64p PROMPT $e[0;65;0;65p PROMPT $e[0;66;0;66p PROMPT $e[0;67;0;67p PROMPT $e[0;68;0;68p prompt cls I should mention that the purpose of the final blank PROMPT command in each of these batch files is to reset the DOS prompt to A> or whatever your default prompt is. It serves no redefinition purpose, but does keep the screen looking clean. USING DEBUG TO LOAD THE ANSI DRIVER While there is no reason why we could not continue to configure our function keys by batch files consisting of lists of PROMPT commands, this is a clumsy way to proceed. It is easier to use the DEBUG utility supplied with DOS to create a .COM file that will do the job for us quickly and directly, without sending any input to screen. To my knowledge this technique was first published by Michael J. Grabel in the December 1984 edition of PC WORLD. Place a formatted DOS disk containing the DEBUG utility in the default drive, and follow the script below. As you do so hexadecimal numbers will appear on the left hand side of your screen. These numbers will vary depending on the configuration of your system. For our purposes here I will represent the numbers in the form xxxx:nnnn. What you will see on your screen will be different. A>DEBUG [enter] -A 100 [enter] MOV AH,9 [enter] MOV DX,109 [enter] INT 21 [enter] INT 20 [enter] xxxx:nnnn DB 1B'[0;59;"EDITOR";13p' [enter] xxxx:nnnn DB 1B'[0;60;"PC-FILE";13p' [enter] xxxx:nnnn DB 1B'[0;61;"PC-CALC";13p' [enter] xxxx:nnnn DB 1B'[0;62;"PC-GRAPH";13p' [enter] xxxx:nnnn DB 1B'[0;63;"PC-TALK";13p' [enter] xxxx:nnnn DB 1B'[0;64;"PC-WRITE";13p' [enter] xxxx:nnnn DB 1B'[0;65;"BASICA";13p' [enter] xxxx:nnnn DB 1B'[0;66;"DIR"p' [enter] xxxx:nnnn DB 1B'[0;67;"MENUOFF";13p' [enter] xxxx:nnnn DB 1B'[0;68;"MENUON";13p' [enter] xxxx:nnnn DB 1B '$' [enter] As soon as you have entered the previous line, your computer will respond with a number in the form of xxxx:nnnn. Copy down the portion of the number that is being represented here as "nnnn" as you will need it later. Once you have copied the number down, press [enter] xxxx:nnnn [enter] -N KEYON.COM [enter] -R BX [enter] When you have entered the command above, your computer will respond with the following line and a colon as a prompt. At this prompt enter 0 and press [enter]. BX:0000 :0 [enter] -R CX [enter] When you enter the R CX command above, the computer will respond with the following line and a colon as a prompt. At this prompt enter the number, "nnnn" you copied down above and press [enter]. CX 0000 :nnnn [enter] -W [enter] The computer will respond with the following. WRITING nnnn bytes -Q [enter] As soon as you enter the Q command (for Quit) you will be back at the DOS prompt, and there will be a new file on disk called KEYON.COM. Simply type it at the DOS prompt and your function keys will be configured. It is a good idea to use this same procedure to write another .COM file called KEYOFF.COM which will restore the keys to their native DOS definitions. The procedure for this is the same as the above, except that the definition section should be: xxxx:nnnn DB 1B'[0;59;0;59p' [enter] xxxx:nnnn DB 1B'[0;60;0;60p' [enter] xxxx:nnnn DB 1B'[0;61;0;61p' [enter] xxxx:nnnn DB 1B'[0;62;0;62p' [enter] xxxx:nnnn DB 1B'[0;63;0;63p' [enter] xxxx:nnnn DB 1B'[0;64;0;64p' [enter] xxxx:nnnn DB 1B'[0;65;0;65p' [enter] xxxx:nnnn DB 1B'[0;66;0;66p' [enter] xxxx:nnnn DB 1B'[0;67;0;67p' [enter] xxxx:nnnn DB 1B'[0;68;0;68p' [enter] xxxx:nnnn DB 1B '$' [enter] If you find that KEYON.COM doesn't work correctly, reboot the machine to clear the definitions and try again. The most common mistakes are typing errors (I often enter a colon when I wanted a semi-colon). Another source of difficulty will arise if you have another file on disk to start with called KEYON.COM or KEYOFF.COM. DEBUG bypasses the normal file allocation of DOS and writes directly to the disk. If you have another file on disk with the same name, DEBUG will overwrite it, but unlesssthe other file was exactly the same size as the new one or smaller, there may be a piece of the old file left over attached to the end of the new one. As a precaution, always erase old versions of the .COM files, or better yet give each one a unique name and rename it later using the DOS Rename command. SOME ADDITIONAL TRICKS Here are some additional control codes for the ANSI driver, summarized from the IBM material. 1. CURSOR POSITIONING To move the cursor to a specified position: ESC [#;#h where the first # is the desired line number and the second the desire column. To move the cursor up without changing columns: ESC [#a where # specifies the number of lines moved. To move the cursor to a specified horizontal and vertical position: ESC [#;#f where # means first the line number and secondly the column number. To get a device status report: ESC [6n To get a cursor position report: ESC [#;#r where the first # specifies the current line and the second # specifies the current column To move the cursor down: ESC [#b where # specifies the number of lines moved down. To move the cursor forward: ESC [#C where # specifies the number of columns moved. To move the cursor backward: ESC [#d where # specifies the number of columns moved. To save the cursor position: ESC [s and to restore it: ESC [u. 2. ERASING To do a CLS (erase screen move cursor to home position): ESC [2j To erase from cursor to end of line: ESC [k 3. COLOR GRAPHICS To set the color/graphics attributes, enter ESC [#;#m where the first # is the desired foreground color and the second is the desired background color. Select colors from the list below: 30 black foreground 31 red foreground 32 green foreground 33 yellow foreground 34 blue foreground 35 magenta foreground 36 cyan foreground 37 white foreground 40 black background 41 red background 42 green background 43 yellow background 44 blue background 45 magenta background 46 cyan background 47 white background To set additional attributes enter: ESC [#m where # is the number of the desired attribute. Select attributes from the list below: 0 all attributes off (white on black) 1 bold on 4 underscore (on IBM Monochrome Display) 5 blink 7 reverse video 8 invisible To give an example of what can be done with these additional codes, a batch file called MENUOFF.BAT containing only the line: PROMPT $e[2J$e[30;40m$h would blank a color display completely. It does a CLS, sets the display to a black foreground and background and the with the "$h" performs a backspace to erase the blinking cursor (the "$h command is documented in the DOS manual under PROMPT). Another batch file called MENUON.BAT containing the lines: PROMPT $e[0m prompt cls Would reset a color display to restore the screen after MENUOFF.BAT had been run. Enjoy ANSI! It is a wonderful tool, and can be a lot of fun to use. It's not a keyboard enhancer, and if you load it up with too many keyboard redefinitions at one time you will run out of environment space. This is harmless and simply means that ANSI is full. But it will work fine to define your function keys and control your screen.