ZX80/ZX81 virtual device for sld output about sjasmplus HOT 2 OPEN

does zxspectrum48 cover these as sort of "superset" of zx80/81, or does the memory map differ enough to make zx48 map invalid for such use? (sorry for entry level question, I know next to nothing about ZX80 and ZX81, I have just seen them like 2-3 times in my life :) ).

from sjasmplus.

Despite Spectrum has been my first computer, I had now to search to find information about it :)

Anyway, depending what you mean with "memory map", here some differences I can see:

• zx81 has 8k ROM (zx80 4k) while spectrum 16k (all starting at 0)
• if I got it properly zx spectrum video memory is strictly below the 32k; zx81 way to handle video has not this limit even if in not true-hires it is "executing" video memory in the upper 32k to display the data in the lower 32k (it is a bit complex to describe the tricks used for video display but I can elaborate further if needed)
• "standard" zx80 and zx81 have just 1kb of memory (from 0x4000 to 0x4400)
• both have no paging feature with standard expansions

Waiting for answer here I found in the documentation that there is a recent instruction that might even be used: "DEFDEVICE". Can this be good to be used?

 DEFDEVICE zx81, $4400, 1
 DEVICE zx81
...

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