Msg: 5119 *Conference*
06-13-94 23:38:42
From: COMET _
To : CHARLES CLARK
Subj: REVERSE-VIDEO
The reason you don't see the inverted white-on-black characters in your ASCII table, is because the inverted characters have the exact same code as the black-on-white characters. The only difference is the screen attribute. To set reverse video mode, output an ESCape character (ASCII 27) followed by a lower-case "p" (ASCII 112). Any printable characters will now display in reverse-video. To reset this mode back to normal, output an ESCape character followed by a lower-case "q" (ASCII 113). Here is a sample BASIC program: 10 RV$=CHR$(27)+"p":REM Reverse video 20 NV$=CHR$(27)+"q":REM Normal video 30 PRINT RV$;"Reverse Video!";NV$ 40 END:REM Demo program by Comet, 1994 This will write "Reverse Video!" in white-on-black characters. Note that I reset the screen graphic rendition back to normal. I used the CHR$(27), since ESCape is not a printable character. Now that you are aware of the fact that the Model 100 knows escape sequences, you are probably wondering about the rest. I'm new here, so I'll leave it to somebody else to point out where these things are documented here, and to demonstrate the machine language CALLs that perform the same tasks.