ULA Control Port: Difference between revisions
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{{Port | {{Port | ||
|Number=$xxFE | |Number=$xxFE | ||
|NumberDec=254 | |||
|ShortDesc=Controls border color and base Spectrum audio settings. | |ShortDesc=Controls border color and base Spectrum audio settings. | ||
|Readable=No | |Readable=No | ||
Revision as of 11:50, 4 May 2020
| Port Number | $xxFE |
|---|---|
| Decimal | 254 |
| Short desc. | Controls border color and base Spectrum audio settings. |
| Bit Mask | |
| Readable | No |
| Writable | Yes |
| Subsystem |
When written to, adjusts the border color and audio devices as follows (soft reset = 0):
| Bit | Function |
|---|---|
| 0-2 | Border color |
| 3 | MIC output (saving via audio jack) |
| 4 | EAR output (connected to internal speaker) |
| 5-7 | Unused |
Reading the port with certain particular high bytes will read the keyboard - see NextPort:$**FE. Bit 6 of the ULA byte is always the EAR input (signal from tape audio jack - also input from Pi digital audio is now mixed in, since 3.0 cores).