Acorn Products Z80 SECOND PROCESSSOR 409 用户手册
The fo11owing tables show the relative address and type of each
register in the Tube, firstly for the Host system, and secondly for
the parasite system (second processor).
Table 1 Host system registers
Address
Address
Read
000
Status flags and Register 1 flags
001
Register 1 (24 byte FIFO read only)
010
Register 2 flags
011
Register 2 (1 byte read only)
100
Register 3 flags
101
Register 3 (2 byte FIFO read only)
110
Register 4 flags
111
Register 4 (1 byte read only)
Address
Write
000
Status Flags
001
Register 1 (1 byte write only)
010
011
Register 2 (1 byte write only)
100
101
Register 3 (2 byte FIFO write only)
110
111
Register 4 (1 byte write only)
Table 2 Parasite system registers
Address
Address
Read
000
Status flags and Register 1 flags Al Fl P V M J I Q
001
Register 1 (1 byte read only)
010
Register 2 flags
011
Register 2 (1 byte read only)
100
Register 3 flags
101
Register 3 (2 byte F1FO read only)
110
Register 4 flags
111
Register 4 (1 byte read only)
Address
Write
000
001
Register 1 (24 byte FIFO write only)
010
011
Register 2 (1 byte write only)
100
101
Register 3 (2 byte FIFO write only)
110
111
Register 4 (1 byte write only)