OS_UpdateMEMC (changes)

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Programmer's OS Reference SWI Manuals Calls

» OS_UpdateMEMCPart 15 – SWI Calls

OS_UpdateMEMC

(SWI &1A)

Use

The purpose of this call is to read or write the contents of the MEMC control register.

Notes

This SWI programs individual bits in the MEMC control register, on machines still supporting Acorn’s custom chipsets. Since the MEMC is write-only, this is done via a software copy, maintained by the OS.

Reg = (RegCopy AND NOT R1) OR (R0 AND R1)

To read: R0,R1 = 0