[Overview][Procedures and functions][Index] | Reference for unit 'x86' (#rtl)

# WritePortB

Write byte to PC port

## Declaration

Source position: line 0

`procedure WritePortB(`
`Port: LongInt;`
`Value: Byte`
`); procedure WritePortB(`
`Port: LongInt;`
`var Buf;`
`Count: LongInt`
`);`

## Description

The first form of WritePortB writes 1 byte to port Port. The second form writes Count bytes from Buf to port Port.

Remark: | You need permission to write to a port. This permission can be set with root permission with the FpIOPerm call.

## Errors

In case of an error (not enough permissions to write to this port), runtime 216 ( Access Violation) will occur.

## See also

FpIOPerm |  | Set permission on IO ports
WritePort |  | Write data to PC port
WritePortL |  | Write longint to PC port.
WritePortW |  | Write Word to PC port
ReadPortB |  | Read bytes from a PC port
ReadPortL |  | Read longints from a PC port
ReadPortW |  | Read Words from a PC port

Documentation generated on: Feb 26 2014