RCA CDP18S711 manual Cassette Data Test

Appendix A - Test and Operating Data 31

Cassette Data Test

Load the following machine language program into memory:

0000 90 B6 B3 F8 33 A6 F8 OA

0008 A3 D3 F8 6F AC F8 40 B9

0010 93 F6 DC 29 99 3A 10 F8

0018 10 A7 F8 08 A9 06 B7 F8

0020 80 FE DC 97 F6 B7 DC 29

0028 89 3A 23 17 87 F6 DC 30

0030 17 30 31 35 00 00 00 00

Rewind a blank cassette and put recorder into record mode. Wait 10 seconds and flip RUN up to initiate the program. The byte at location 0033 will be continuously recorded on tape. Flip RUN down to stop recording after a minute or so. You can play this tape to check the signals shown below. You can also load the tape into memory for testing purposes. Load 7 pages starting at 0100. You can use this tape to determine the proper volume control setting for your recorder. You can change the recorded byte at 0033 if desired. Bits on tape consist of one cycle at 2 kHz for

"0" or one cycle at 0.8 kHz for "1". Data format is 4 seconds of continuous "0's" for sync followed by the specified number of data bytes. Bytes always begin with a "1" start bit (S) followed by 8 data bits (0-7), and end with a parity bit (P). Odd byte parity is used in this code. The waveforms below show how a 35 byte would appear on tape. The operating system translates memory bytes to bit serial output via the Q output line. Bit serial input from tape is received via input flag 2 and translated into parallel form for storage in memory by the operating system software.

A-OUTPUT OF U14A

B-OUTPUT FROM CASSETTE (TAP IN PAD ON CARD) C-OUTPUT OF U14B

* WAVEFORMS SHOWN FOR PANASONIC MODEL RO-413S RECORDER.