193 lines
6.5 KiB
Plaintext
193 lines
6.5 KiB
Plaintext
anchor:cassette_tape[]
|
|
|
|
=== Cassette Tape Interface
|
|
|
|
The Apple ][ and Apple ][ plus machines have the ability to save and load binary
|
|
data to and from cassette tape. The user would attach a standard cassette tape
|
|
recorder to the jacks on the back of the Apple ][, and use the monitor commands
|
|
+R+ and +W+, or the BASIC commands +LOAD+ and +SAVE+, to read and write data
|
|
on the cassette tape. The user would have to press the play and/or record buttons
|
|
on the player at the right time.
|
|
|
|
The Apple ][ has two cassette ports, CASSETTE IN and CASSETTE OUT. To save a program to
|
|
tape, the user would attach a cassette recorder to the CASSETTE OUT port, load a blank
|
|
cassette into the recorder, press RECORD (and PLAY), then on the Apple type SAVE. When
|
|
finished, the user would press STOP, and eject the tape.
|
|
|
|
To load a previously saved program
|
|
from tape, the user would attach the player to the CASSETTE IN port, then load and REWIND
|
|
the tape. The user would PLAY the tape until the header tone could be heard, then STOP.
|
|
On the Apple ][ the user would type LOAD and immediately press PLAY on the cassette player.
|
|
After the file loaded, the user would STOP and eject the tape.
|
|
|
|
The Epple ][ emulates the cassette interface, using a standard WAVE (PCM) file to
|
|
hold the recorded portion of the tape. It provides two ports, one for CASSETTE IN and
|
|
a separate one for CASSETTE OUT. Generally you'll use only one at a time. Use CASSETTE IN
|
|
for LOADing a program, or CASSETTE OUT for SAVEing a program.
|
|
|
|
To load a program from a cassette image WAVE file, use +cassette load+
|
|
to put the tape into the cassette player. The tape will automatically rewind and
|
|
advance to the header tone. Then use the Apple LOAD command to load the program
|
|
from the tape. If the Apple gives you +ERR+, that means it could not interpret the
|
|
WAVE audio correctly.
|
|
If you want to rewind the tape, you can use the +casssette rewind+ command.
|
|
Use +cassette eject in+ to close the file.
|
|
|
|
To save an in-memory program to a cassette tape image WAVE file, use
|
|
+cassette blank <file-path>+ to put a new blank tape image into
|
|
the cassette recorder. Then use the Apple SAVE command to record to the tape, and then
|
|
+cassette save+ to save the WAVE file. Use +cassette eject out+ to close the file.
|
|
|
|
The emulator will not overwrite existing data in a tape image file.
|
|
|
|
==== Commands
|
|
|
|
+cassette load [ <file-path> ]+
|
|
|
|
This loads an existing WAVE file (from the host computer) containing a cassette tape image
|
|
onto the CASSETTE IN port,
|
|
in preparation for loading the program from it. If +file-path+
|
|
is omitted, a dialog box will be presented to select the file to load.
|
|
The tape is automatically positioned at the first header tone.
|
|
|
|
+cassette rewind+
|
|
|
|
This command rewinds the tape currently on the CASSETTE IN port. After rewinding
|
|
the tape, you will typically need to fast-forward to the head tone using
|
|
the +cassette tone+ command.
|
|
|
|
+cassette tone+
|
|
|
|
If more than one program is stored in one WAVE file, then after loading the first
|
|
program, you may need to fast-forward to the next header tone. This command will
|
|
do just that.
|
|
|
|
+cassette blank <file-path>+
|
|
|
|
This creates a new empty file (on the host computer) that represents a cassette tape image,
|
|
and loads it onto the CASSETTE OUT port,
|
|
in preparation for saving a program to it.
|
|
The file must not already exist. The file type should be +.wav+ to indicate a WAVE format file.
|
|
|
|
+cassette save+
|
|
|
|
This command saves the changed tape to the file. Note that the display will show
|
|
an asterisk +*+ next to the file name if there are unsaved changes that need to
|
|
be saved.
|
|
|
|
+cassette eject { in | out }+
|
|
|
|
This removes the file from the specified cassette port (CASSETTE IN port, or CASSETE OUT port).
|
|
|
|
==== Example of Saving to Tape
|
|
|
|
Start up the emulator with Applesoft ROMs for this tutorial.
|
|
Enter a simple Applesoft program, just as an example, that we
|
|
are going to save to a cassette tape image file.
|
|
|
|
[source,vbs]
|
|
------------------------
|
|
]NEW
|
|
|
|
]10 PRINT "HELLO"
|
|
|
|
]20 END
|
|
|
|
]LIST
|
|
|
|
10 PRINT "HELLO"
|
|
20 END
|
|
|
|
]RUN
|
|
HELLO
|
|
------------------------
|
|
|
|
We first need to load a tape image file into the cassette machine.
|
|
Enter command mode by pressing +F5+, then make a new tape
|
|
image file.
|
|
|
|
------------------------
|
|
command: cassette blank hello.wav
|
|
------------------------
|
|
|
|
This will create a new, empty tape file image named +hello.wav+
|
|
in the current default directory. (We could have specified a full path
|
|
name for the file if we wanted to place it in a different directory.)
|
|
Notice that the emulator now displays the name of the tape image file.
|
|
|
|
Next, we tell Applesoft to save the program to the cassette. For this,
|
|
we just use the +SAVE+ command. Note that this is not the
|
|
DOS +SAVE+ command; the DOS command has a file name after
|
|
+SAVE+. We just use +SAVE+ with no file name.
|
|
|
|
[source,vbs]
|
|
------------------------
|
|
]SAVE
|
|
------------------------
|
|
|
|
It will take 10 seconds or so for it to save. Notice that the
|
|
current position of the tape is counting up as the Apple saves
|
|
the program. When it is finished, you need to save the changes
|
|
to the file. Press +F5+ and enter the emulator command to save
|
|
the tape image file.
|
|
|
|
------------------------
|
|
command: cassette save
|
|
------------------------
|
|
|
|
Now do a NEW to clear the program, and LIST to prove that it's gone.
|
|
|
|
[source,vbs]
|
|
------------------------
|
|
]NEW
|
|
|
|
]LIST
|
|
------------------------
|
|
|
|
We can now eject the tape (close the file).
|
|
|
|
------------------------
|
|
command: cassette eject out
|
|
------------------------
|
|
|
|
==== Example of Loading from Tape
|
|
|
|
To load the saved program (from the previous section) into the Apple again,
|
|
we will need to first load the tape image file back into the cassette machine.
|
|
Press +F5+ to enter command mode and load the image file.
|
|
|
|
------------------------
|
|
command: cassette load
|
|
------------------------
|
|
|
|
This will bring up the Open File dialog box. Choose
|
|
hello.wav file you just saved. Notice the
|
|
emulator now displays the name of the tape image file, along with the
|
|
position and length of the tape image. Notice the emulator automatically
|
|
advances the tape to the first header section.
|
|
|
|
Next, we tell Applesoft to load the program from the cassette. For this,
|
|
we just use the +LOAD+ command. Note that this is not the
|
|
DOS +LOAD+ command; the DOS command has a file name after
|
|
+LOAD+. We just use +LOAD+ with no file name.
|
|
|
|
[source,vbs]
|
|
------------------------
|
|
]LOAD
|
|
------------------------
|
|
|
|
It will take several seconds for it to load. Notice that the
|
|
current position of the tape is counting up as the Apple loads
|
|
the program. When it is finished, the program will be loaded.
|
|
|
|
[source,vbs]
|
|
------------------------
|
|
]LIST
|
|
|
|
10 PRINT "HELLO"
|
|
20 END
|
|
|
|
]RUN
|
|
HELLO
|
|
------------------------
|