Difference between revisions of "Internal Port Decoding b0-7 Register"

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|Readable=Yes
 
|Readable=Yes
 
|Writable=Yes
 
|Writable=Yes
|ShortDesc=Enabling internal ports
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|ShortDesc=Enabling internal ports decoding
 
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Revision as of 09:07, 12 November 2019

Number $82
Readable Yes
Writable Yes
Short Description Enabling internal ports decoding
Bit Description
7 Enabling Kempston Joystick 2, Joystick I/O ($xx37 / 55) (also MD2 controller)
6 Enabling Kempston Joystick ($xx1F / 31) (also MD1 controller)
5 Enabling Datagear DMA Port ($xx6B / 107)
4 Enabling +3 floating bus
3 Enabling Plus 3 Memory Paging Control ($1FFD / 8189)
2 Enabling Next Memory Bank Select ($DFFD / 57341)
1 Enabling Memory Paging Control ($7FFD / 32765)
0 Enabling Timex Sinclair Video Mode Control ($xxFF / 255)

All bits are set to 1 upon soft reset.

(note: Next registers with number higher than $7F are inaccessible from Copper code)