ZX ports

Hi, All !
Ports for ZX SPECTRUM are listed here 48K
┌────────────── ────────────────────── ────────────────────── ─────────────────┐
│ Full Write Read │
│ address WR RD │
│ H L 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 │
│ NN FE SO TO G R B TI Keyboard │
│ 1F Light pen │
│ 3F │
│ FB PRINTER │
│ INERFACE 1 │
│ (microdrive & RS-232/NETWORK) │
│ EF CONTROL 1 │
│ E7 data │
│ F7 RS-232/NETWORK │
│ INTERFACE 2 │
│ EF FE joystick 1 │
│ E7 FE joystick 2 │
│ Drive controllerTR-DOS │
│ FF control status │
│ 1F command status │
│ 3F track │
│ 5F sector │
│ 7F data │
└──────────────── ────────────────────── ────────────────────── ───────────────┘
No the specified high byte is not checked.
1F and 3F conflict with the ports of the 1818VG93 drive. The problem is resolved as follows:
when the TR-DOS controller is activated, access to its ports and ROM is allowed;
in addition, it moves the DE ROM (ROM CS) line to state 1, disabling
the internal ROM of the machine (it should be used to disable the conflict. ports.
If the 580ВВ55 port is used at addresses 1F,3F,5F,7F, it is set to 6(CS).
The control is activated when a command is selected from a ROM cell with the address
3D00...3DFF or by a system reset signal and non-mask. interruptions.

With respect.
Vasek.

... Dr.Basile's Station 2:5005/53.22