ULA Control Port

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Revision as of 15:52, 29 August 2017 by wiki>Hyphz (Created page with "{{Port |Number=$xxFE |ShortDesc=Controls border color and base Spectrum audio settings. |Readable=No |Writable=Yes }} When written to, adjusts the border color and audio devic...")
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Number $xxFE
Decimal
Short desc. Controls border color and base Spectrum audio settings.
Bit Mask
Readable No
Writable Yes
Subsystem

When written to, adjusts the border color and audio devices as follows:

Bit Function
0-2 Border color
3 Enable MIC output
4 Enable EAR output
5-7 Unused

Reading the port with certain particular high bytes will read the keyboard (see Template:PortNo:$**FE. Bit 6 of the ULA byte is always the EAR input.