At hardware assembly level, modern memory access controlled via MMU / MMU emulation[0][1][2].

Just based on title description, any language that can set read/write status to file can create 'write-only' memory. aka remove all permissions but 'write'

Note: Context for files is unix 'swap' / in-memory files.

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[0] : https://retrocomputing.stackexchange.com/questions/9664/prot...

[1] : https://retrocomputing.stackexchange.com/questions/9664/prot...

[2] : https://news.ycombinator.com/item?id=17508529