ZX80 / ZX81 Memory (RAM) Size Program

[spocek]

This program checks how much memory (RAM) is present (with or without the memory expansion):

1 POKE 18000, 33
2 POKE 18001, 11
3 POKE 18002, 0
4 POKE 18003, 57
5 POKE 18004, 68
6 POKE 18005, 77
7 POKE 18006, 201
8 PRINT (USR(18000) - 16373) / 1024; "K"