QB64-PE/internal/help/OUT.txt

[[OUT]] writes values to register and port hardware addresses.


{{PageSyntax}}
: [[OUT]] {{Parameter|registerAddress%}}, {{Parameter|value%}}


{{Parameters}}
* {{Parameter|registerAddress%}} is a value expressed as a decimal [[INTEGER]] or [[&H|hexadecimal]].
* The [[INTEGER]] {{Parameter|value%}} sent is normally only 0 to 255 per byte register (8 bit) address.


{{PageDescription}}
* '''QB64 has limited access to registers. VGA memory and registers are emulated.'''
* OUT can be used to change color port and a limited number of other port settings in QB64.
* Some settings may be set in a specific order to gain access to settings and [[INP]] reads.
* [[SCREEN]] modes determine the number of available color palette attributes from 2 to 256 in SCREEN 13.
* Windows NT may block access to Parallel printer and Serial ports. See [[Port Access Libraries]] or other DLLs.
* [[_PALETTECOLOR]] can also be used to set RGB intensity values using [[_RGB32|32 bit color]] values.
* OUT can toggle the blinking attribute of SCREEN 0 color 16-31 for legacy code. [[_BLINK]] is the preferred method. (starting with build 20170816/61).


==Color Port Palette access using OUT==

:::::{{InlineCode}}OUT &H3C7, attribute{{InlineCodeEnd}} : Set port to read RGB settings for start attribute
:::::{{InlineCode}}[[INP]] &H3C9, colorIntensity{{InlineCodeEnd}} : Reads RGB color intensity settings in order

:::::{{InlineCode}}OUT &H3C8, attribute{{InlineCodeEnd}} : Set port to write RGB settings for start attribute
:::::{{InlineCode}}OUT &H3C9, colorIntensity{{InlineCodeEnd}} : Writes RGB color intensity settings in order

::::* Every 3 reads or writes, changes to next color attribute without a set
::::* Color setting is Red, Green and Blue attribute intensities in order. 
::::* Color attribute intensity values range from 0 to 63.
::::* Some [[DAC]] color attribute intensities cannot be changed using OUT.


==QBasic/QuickBASIC==
* In DOS, OUT accesses memory and hardware directly, unlike [[POKE]], and could cause PC damage.


{{PageExamples}}
''Example 1:'' Reading the default RGB color settings of color attribute 15.

{{CodeStart}} '' ''
{{Cl|OUT}} &H3C7, 15      'set color port attribute 15 for a read
red% = {{Cl|INP}}(&H3C9)
green% = INP(&H3C9)
blue% = INP(&H3C9)
PRINT red%, green%, blue% '' ''
{{CodeEnd}}
{{OutputStart}}
 63       63       63
{{OutputEnd}}


''Example 2:'' Changing the color intensity settings of the [[SCREEN]] background [[COLOR]] 0 to bright white.
{{CodeStart}} '' ''
{{Cl|OUT}} &H3C8, 0  'attribute number. 0 for black screen background
{{Cl|OUT}} &H3C9, 63 'red
{{Cl|OUT}} &H3C9, 63 'green
{{Cl|OUT}} &H3C9, 63 'blue '' ''
{{CodeEnd}}
:''Explanation:'' In [[SCREEN]] 0 this is one way to make high intensity background colors. {{InlineCode}}[[COLOR]] ,15{{InlineCodeEnd}} is actually grey (7).


''Example 3:'' Toggling blinking colors in SCREEN beginning with build 20170816/61
{{CodeStart}} '' ''
{{Cl|OUT}} &H3C0, &H10  'disables blinking and enables high intensity backgrounds (colors 16-31)
{{Cl|OUT}} &H3C0, 2 ^ 3 'reenables blinking and disables high intensity backgrounds  (colors 16-31)
{{CodeEnd}}
: Note: In QB64, the recommended practice is to use the [[_BLINK]] {ON|OFF} statement.


''Example 4:'' Restoring colors to a bitmap from the Red, Green and Blue [[BSAVE]]d indexed array of color values.
{{CodeStart}} '' ''
 {{Cl|SCREEN (statement)|SCREEN}} 12
 {{Cl|OUT}} {{Cl|&H}}3C8, 0 ' set color port for output at attribute 0
 {{Cl|FOR...NEXT|FOR}} i = 0 {{Cl|TO}} 47 ' 48 RGB values is (3 * 16) -1 color attributes from 0 in screen 12
   {{Cl|OUT}} {{Cl|&H}}3C9, Image%(i) ' changes to next attribute after 3 RGB loops
 {{Cl|NEXT}}
 {{Cl|PUT (graphics statement)|PUT}}(clm, row), Image(48) PSET '' ''
{{CodeEnd}}
:''Explanation:'' The color RGB intensity settings were imported from a file to the Image array using [[BLOAD]]. The color attribute advances to the next one every 3 writes using OUT. The color information was indexed to the start of the array. The image is after the color settings at index 48. Index 48 is the [[GET (graphics statement)|GET]] image width and 49 is the height.


{{PageSeeAlso}}
* [[PALETTE]], [[_PALETTECOLOR]]
* [[INP]] {{text|(read register)}}
* [[PEEK]] {{text|(read memory)}} 
* [[POKE]] {{text|(write to memory)}}
* [[COLOR]], [[SCREEN]] 
* [[BSAVE]], [[BLOAD]]
* [[_BLINK]], [[_BLINK (function)]]
* [[Port Access Libraries]] {{text|(COM or LPT registers)}}


===External Links===
* [http://en.wikipedia.org/wiki/Input/output_base_address#Common_I.2FO_base_address_device_assignments_in_IBM_PC_compatible_computers PC I/O base address device assignments]


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