If you want to transfer files from your MZ to a PC using a sound card you need a software ( e.g. tapeload 27 kb written by Marukun / Tokyo ), a copy program for the MZ, and a cinch connector cable. This is to be connected to the external write connector P-7 at the back of the MZ. The cinch connector P-7 is used normally to connect an external data recorder to the MZ.
There will be no problem to do this if you use the models MZ-711 or MZ-811, both types are internally wired to the connector P-7. The models MZ-721, MZ-731 and MZ-821 are not because a data recorder is inbuilt. This means, an extra connection is required between pin 1 ( external write ) of the connector P-12 and pin 7 ( write ) of P-12. To this a short wire between both pins must be soldered.
Next connect the MZ ( external write ) to the soundcard of the PC ( aux input ).
To test the connection use the monitor program, type in S120022001200, and use any filename e.g. "test". You'll hear the sound of the data writing by the PC-Speaker. If you don't hear anything, don‘t try to use the tapeload program, it will not work.
Be sure that the auxilary entry is authorized ( Option, Properties ), the Mute Control is not selected, and the volume sliders of both Volume Control and Auxiliary are at their upper position.
Now connect the floppy drive to the MZ and use a copy program to transfer the data from the MZ to the PC. Follow the instructions in the text file of tapeload 27 kb.
Be sure the copy program works wright on the MZ.
I've tested the program with a SB128PCI, SB32, and a Yamaha Sound Card, it works fine.