It's a ZX81 as well !
Even with the NMI generator board and switchable ROMs.
You can switch between ZX80, ZX81, maybe Lambda, ASZMIC.
Or even switch same OS with different fonts.
Or drivers included.
If you put a 64kByte EPROM in it, you can choose between 16 overlapping 4k-16k pages.
You can use 4k ROMs, 8k ROMs, 12k ROMs mixed.
For example you can use a ZX80 ROM, ZX81 ROM and a 4k page for drivers which is accessable from both ZX80 and ZX81 ROM.
Or you put up to 8 charsets in the ROM which can be used either from ZX80 or ZX81 by simply changing the I register with a simple program.
I think some people can heck out some more useful ideas ...
![Cool 8-)](./images/smilies/icon_cool.gif)