[INP](INP) returns a value from a computer register or port values at a specified physical address. ## Syntax > i = [INP](INP)(address) * **QB64 has limited access to registers. VGA memory and registers are emulated.** * Address can be a decimal or hexadecimal [INTEGER](INTEGER) value. * [INP](INP) reads directly from a register or port address. * It does not require a [DEF SEG](DEF-SEG) memory segment address like [PEEK](PEEK) or [POKE](POKE) do. * Reads color port intensity settings after `[OUT](OUT) &H3C7, attribute` sets the starting attribute read mode. ## Example(s) Reading the current RGB color settings used in a bitmap to an array. ```vb SCREEN 12 DIM Colors%(47) OUT &H3C7, 0 ' set color port for INP reads at attribute 0 to start FOR i = 0 TO 47 Colors%(i) = INP(&H3C9) ' moves to next color attribute every 3 loops NEXT ``` Reading the keyboard Scan Codes as an alternative to [INKEY$](INKEY$) ```vb DO: SLEEP scancode% = INP(&H60) a$ = INKEY$ ' clears keyboard buffer PRINT scancode%; LOOP UNTIL scancode% = 1 ' [ESC] keypress exit ``` A simple ping pong game using an array function to read multiple keys for two players. ```vb DEFINT A-Z SCREEN 12 DIM ball%(100) ' Set aside enough space to hold the ball sprite CIRCLE (4, 3), 4, 4 PAINT (4, 3), 12, 4 ' Draw a filled circle and fill for ball GET (0, 0)-(8, 7), ball%(0) ' Get the sprite into the Ball% array begin: xmin = 10: ymin = 10 xmax = 630: ymax = 470 x = 25: y = 25 dx = 1: dy = 1 LTpos = 50: RTpos = 50 DO: _LIMIT 100 'adjust higher for faster CLS IF ScanKey%(17) THEN LTpos = LTpos - 1 IF ScanKey%(31) THEN LTpos = LTpos + 1 IF ScanKey%(72) THEN RTpos = RTpos - 1 IF ScanKey%(80) THEN RTpos = RTpos + 1 PRINT "Player 1 : "; ponescore; " Player 2 : "; ptwoscore IF x > xmax - 15 AND y >= RTpos AND y <= RTpos + 100 THEN dx = -1 ELSEIF x > xmax THEN ponescore = ponescore + 1 GOSUB begin END IF IF x < xmin + 15 AND y >= LTpos AND y <= LTpos + 100 THEN dx = 1 ELSEIF x < xmin THEN ptwoscore = ptwoscore + 1 GOSUB begin END IF IF y > ymax - 5 THEN dy = -1 IF y < ymin + 5 THEN dy = 1 ' Display the sprite elsewhere on the screen x = x + dx y = y + dy PUT(x, y), ball%(0) LINE (20, LTpos)-(20, LTpos + 100) LINE (620, RTpos)-(620, RTpos + 100) _DISPLAY 'shows completed screen every call LOOP UNTIL ScanKey%(1) END FUNCTION ScanKey% (scancode%) STATIC Ready%, keyflags%() IF NOT Ready% THEN REDIM keyflags%(0 TO 127): Ready% = -1 i% = INP(&H60) 'read keyboard states IF (i% AND 128) THEN keyflags%(i% XOR 128) = 0 IF (i% AND 128) = 0 THEN keyflags%(i%) = -1 K$ = INKEY$ ScanKey% = keyflags%(scancode%) END FUNCTION ``` > *Note:* [_KEYDOWN](_KEYDOWN) can be used to read multiple keys simultaneously and is the **recommended practice**. ## See Also * [OUT](OUT) (write to register), [PEEK](PEEK) (read memory) * [INKEY$](INKEY$), [_KEYHIT](_KEYHIT), [_KEYDOWN](_KEYDOWN) * [Bitmaps](Bitmaps), [Scancodes](Scancodes) (keyboard) * [Port Access Libraries](Port-Access-Libraries) (COM or LPT registers) ## External Links * [PC I/O base address device assignments](http://en.wikipedia.org/wiki/Input/output_base_address#Common_I.2FO_base_address_device_assignments_in_IBM_PC_compatible_computers)