30 | RCA COSMAC VIP Instruction Manual |
Cassette Attachment Diagram
Cassette Phase Test
For best results your cassette recorder should not reverse the phase of an input signal on playback. When playing back a tape recorded on another recorder, it should not reverse the phase of the output signal. You may have to reverse the internal head connections on some cassette recorders to eliminate unwanted phase reversals.
To check for phase reversals, load the machine language test program, given below, into memory.
Run this program to generate a phase test signal on the tape out line. Record one minute of this test signal, then play it back and observe the cassette recorder output on a scope. It should appear as shown in B or C below. Save this tape to test new recorders on which you want to play tapes you have recorded on a previously tested machine. If the playback signal appears upside down from that shown in B or C, you will have to reverse the internal head connection leads on the
Test Program
0000 | F8 | 04 | AA | 7B | F8 | 0C | FF | 01 |
0008 | 3A | 06 | 7A | F8 | 0C | FF | 01 | 3A |
0010 | 0D | 2A | 8A | 3A | 03 | F8 | 60 | FF |
0018 | 01 | 3A | 17 | 30 | 00 | 00 | 00 | 00 |
