Multiplex

Here is some really old code I wrote that uses the multiplex interrupt to detect a previous instance of the TSR... I hope it helps!

Code:

$COMPILE EXE
$OPTION cntlbreak OFF
$error ALL ON

    RANDOMIZE TIMER
    IF VAL(COMMAND$) < 10 THEN
    PRINT "Incorrect time parameter!"
    PRINT "Format: SLEEP n  (where n is the number of seconds to activate, > 10)"
    END
    END IF

    Dummy& = setmem(-700000)

    POPUP MULTIPLEX &HC000, 254   ' reg AX and DX get this pattern as an ID
    REG 1, &HC000 : REG 4, 254    ' set pattern to check for already installed
    CALL INTERRUPT &H2F           ' do the multiplex interrrupt
    IF REG(1) <> &HC000 AND REG(4) <> 254 THEN
    PRINT "Screen Saver already installed."
    PRINT "Popup using ALT-F10 and then press ALT-F10 again to de-install."
    END                     ' We were already installed
    END IF

    popup key CHR$(8,&H44,&H73)
    popup quiet CLNG(18.2 * VAL(COMMAND$))
    SwapName$ = LEFT$(CURDIR$,2) + "\SLEEP$$$.SWP"

    PRINT "Screen Saver installing with a" CLNG(VAL(COMMAND$)) "Second delay."
    PRINT "(Use ALT-F10 to pop-up the screen saver if required)"
    popup SLEEP USING ems, SwapName$

'***************************************************************************

DO
    IF popup(4) = 16 AND REG(1) = &HC000 AND REG(4) = 254 THEN
    reg(1), &HC001
    reg(4), 252
    popup SLEEP
    END IF
    Mx% = pos
    My% = csrlin
    $INCLUDE "SERIALN§.BAS"

    DisplayAddress& = (pbvScrnBuff \ &H010000)

    def seg = DisplayAddress&               ' Save copy of screen
    ScreenSaverTemp$ = PEEK$(0,4000)            ' Save screen

    LOCATE 1,1,0 : PRINT "A";               ' Display test char
    ForeGrnd% = PEEK(1) MOD 16          ' Calculate fore color
    BackGrnd% = PEEK(1) \ 16                ' Calculate back color
    POKE$ 0, ScreenSaverTemp$               ' Overwrite test char
    RANDOMIZE TIMER

    z$ = "Screen Saver running"

    DO
    y% = RND(1,24)
    x% = RND(1,80- LEN(z$))
    COLOR 0,0
    CLS
    COLOR RND(1,15), RND(1,15)
    LOCATE y%, x%     : PRINT z$;
    LOCATE y% + 1, x% : PRINT "Press any key...";
    COLOR 7
    SLEEP 1
    a$ = INKEY$
    COLOR 15,4
    LOCATE 25,1
    IF a$ = CHR$(0,113) AND ISTRUE popup(1) THEN
        PRINT SPACE$(26) "Screen saver uninstalling..." SPACE$(26);
        delay 1
    ELSEIF a$ = CHR$(0,113) THEN
        PRINT SPACE$(20) "Unable to Uninstall,  vectors blocked!" SPACE$(21);
        delay 2
        a$ = CHR$(32)
    END IF
    LOOP WHILE a$ = ""

    LOCATE My%, Mx%, 1                  ' Restore location
    COLOR ForeGrnd%, BackGrnd%          ' Restore colors
    sound 0,0
    POKE$ 0, ScreenSaverTemp$
    def seg

    IF a$ = CHR$(0,113) THEN EXIT LOOP
    clear
    popup SLEEP
LOOP UNTIL 0
END

'***************************************************************************

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Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

Having given up in self disgust for a week or two on making the POPUP MULTIPLEX work, I have come back to it and I'm about ready to give up again...would some kind soul post a simple bit of code showing how the darn thing works from both ends? I've pushed values into the registers till I ran out of numbers and get no response from it

Also..

slightly but not directly related, I have a bit of code to access a tsr that requires puts a value in CX and gets an answer in either EAX, ECX, EBX or EDX. Ummm....is this possible in PB? All the PB related examples I have seen use two letter register ID's...

Remember, I'm still learning this raw DOS stuff (I've been crippled by Paint-It-By-Numbers Windows programming)so be gentle with me...

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Multiplex