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8-bit acorn hardware • Re: Time & Config.

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Depending where you do it in the BREAK process, and how it interacts with the configured/default filing system, you might be able to do it with:
OSARGS 0,0 - read FS
Service 18,5 - select NFS
Write the info
Service 18,oldfs or OSBYTE 140/141 - reselect previous FS
The problem is when to do it: too early, and NFS will simply overwrite it with its own default; too late, and NFS might have already loaded a boot file from the wrong server. It will take serious pouring over disassembly to find out if this is possible.
That's what my SoftNVRAM code does - sticks &FF at location &FF, and disallows writes to it.
I think I want to allow writes. Changing it doesn't have any dire consequences, and it means you can use *FX162,255,0 to mean "treat next break as an R-break". But I might change my mind.
Though, thinking about it it probably should be &FE, to indicate you can write to &00-&FE. Hmm. My soft-loaded NVRAM does it properly, I should probably fix my ROM version to do it properly as well. :)
The Compact is inconsistent. It returns &7F for &80 useable bytes, but &FF for &FF useable bytes. I think I'll stick with &FF, and assume the first is wrong. This allows for the possibility of returning 0 for no NVRAM.

Statistics: Posted by Barneyntd — Sun Jan 19, 2025 8:19 pm



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