Connect the two computers using a Laplink parallel cable to use this feature:
+----------------------------------------+ |A-name A-End B-End Descr. Port/Bit | +----------------------------------------+ |DATA0 2 15 Data 0/0x01 | |-ERROR 15 2 1/0x08 | +----------------------------------------+ |DATA1 3 13 Data 0/0x02 | |+SLCT 13 3 1/0x10 | +----------------------------------------+ |DATA2 4 12 Data 0/0x04 | |+PE 12 4 1/0x20 | +----------------------------------------+ |DATA3 5 10 Strobe 0/0x08 | |-ACK 10 5 1/0x40 | +----------------------------------------+ |DATA4 6 11 Data 0/0x10 | |BUSY 11 6 1/0x80 | +----------------------------------------+ |GND 18-25 18-25 GND - | +----------------------------------------+
See also this note on the Mobile Computing page.