INTERFACE 1 HOOK CODE SUMMARY
=============================

This is a summary of each Hook Code, it's name, shadow ROM location and
function.

Code Name     ROM1 ROM2 ROM3   Function
---- ----     --------------   --------
1B   PAUSE    19D9 1ECD 1ECF   Wait for key to be pressed - value A.
1C   PRINT    19EC 1EE0 1EE2   print CHR$ A on system stream $FE (the screen).
1D   232IN    0B81 0B88 0B88   RS232 input in A - carry if invalid.
1E   232OUT   0C5A 0D07 0D07   RS232 output character code in A.
1F   LPRINT   19FC 1EF0 1EF2   print CHR$ A on stream 3 (the printer).
20   SCAN_K   1A01 1EF5 1EF7   scan the keyboard matrix - NZ if any pressed.
21   MOTOR    17F7 1532 1532   switch microdrive motors on or off.
22   OPEN_M   1B29 1B05 1B05   open a temporary "M" channel.
23   CLOSE_M  12A9 138E 138E   close a "M" channel.
24   ERASE_M  1D6E 1D79 1D7B   erase a file from a cartridge.
25   READ_NP  1A09 1EFD 1EFF   read in the next PRINT buffer.
26   WRITE_S  11FF 12DA 12DA   send the "M" buffer to the cartridge.
27   READ_P   1A17 1F0B 1F0D   read in a PRINT buffer.
28   READ_R   1A4B 1F3F 1F41   search for a random file.
29   READ_S   1A86 1F7A 1F7C   search for a serial file.
2A   WRITE_R  1A91 1F85 1F87   write a block randomly.
2B   MAKE_M   ---- 10A5 10A5   create "M" area.
2C   RECLAIM  10C4 119F 119F   reclaim a 595 byte "M" channel.
2D   OPEN_N   0EA9 0F46 0F46   open a temporary "N" channel.
2E   CLOSE_N  1A2F 1F18 1F1A   close a "N" channel.
2F   READ_N   ---- 1F25 1F27   read a Network packet.
30   WRITE_N  0DB2 0E4F 0E4F   write a Network packet.
31   NEWVARS  19A8 1E98 1E9A   create the extra system vars if required.
32   SHADOW   19A4 1E94 1E96   call the shadow ROM routine addressed.
33   SCAN_M   ---- 1FE4 1FE6   read the next cartridge header.
34   OPEN_B   ---- 1FF6 1FF8   open "B" channel.

Source: Master Your ZX Microdrive by Andrew Pennell.