Compability with Spectrum 128K
Original interface I didn't test with
Spectrum 128K, any modell, but due to use of A1 it probably not
will work 100% OK with 128K machines.
Therefore I modified some addresses. Circuit diagram (scheme) is
same, but address lines which lead directly from Spectrum to IDE
connector must be changed. So, to A0 of IDE goes A2 of ZX, to A1
of IDE goes A6 of ZX and to A2 of IDE goes A7 of ZX.