Tape data decoding help required...

[Danii]

Hello all,

An old wirecut machine who's dedicated computer (80's made) is not working now. The computer has a display console and boots from flopy. It takes NC code input through keyboard and record all the data to a Magnatic Tape(cessate In GCODE). This cassate then goes to the machine and machines tape reader reads data (i.e NC commands) and opreates the motors of machine.

Now the problem is that the computer is deffected and is not working any more also no support what so ever.

Now What i need to do is to understand the formate of data on the magnatic tape for which i want to translate the data of Magnatic tape(Cassate) to through my computer's sound card.

I donot know how to proceed. Does anyone knows how to decode data on magnatic tape specially when it is in the form of Two tones.

regards
Danii....

[Al_The_Man]

I have come across these in the past but never bothered to analyize them, You could may be use a scope and see if you can detect a pattern, paper tapes are written in ASCII or EIA format, I imagine these are the same as they have to be ones & Zeros I assume, and are probabally asyncronous serial.
But the big problem is if you do identify the pattern, how to transcribe off the tape to digital storage media.
Al.

[Danii]

Hello and Thanks Al_The_Man

The data read from audio tape through sound card and soundforge software.

Actullay the machine is JAPAX EDM wircut. The Tape reader is ok but the writer computer is not working. I want to link it with computer. Do you know any other way to do this . I thought if i can decode and understand the data written on tape then i can use cassete simulator which take the audio in signal and simulate it on tape reader which takes it as normal audio tape. But it is just a thought do you know any other way to make new data cessets.

regards
dani

[dpuch]

The tape format for ISO g-code is just a binary 7-bit representation of the ASCII characters. With the 8th bit as parity (bit 7) so if there are an odd number of 1 bits for bit 0-6 bit 7 also =1

bits 7 6543210 <-- space between bits 6 and 7 for clarity only
--------------
0 = 0 0110000
1 = 1 0110001
2 = 1 0110010
...

A = 0 1000001
B = 0 1000010
C = 1 1000011
...

Note 0-9 and A-Z are sequential so the bits 0-6 are just counting up in binary.

Dale

[Al_The_Man]

Originally Posted by Danii The data read from audio tape through sound card and soundforge software.

Unfortunately there does not appear to be enough information to decode the format, It is pretty sure to be asynchronous serial data, I would think it will be very close to a standard RS232 serial format, you would need to capture several blocks of words to actually decifer the system they use.
Then you may be able to condition the signal and feed it into a RS232 reciever IC or port.
The trick will be to decifer the protocol, baud rate etc.
Al.

[dpuch]

Another thought is to ask for assistance from a company that makes/sells BTR's.
http://www.mis-group.com/hardware/btr.php
I'm sure they will charge for it, but they may be able to help you. You may be able to get some info on the output of the tape though.

Another thing... If the CNC control is dead, how useful is the original G-code? Moving that code to another machine/setup may be as problematic as generating the code from scratch.

Dale

[tobyaxis]

Have you looked at the Machinist Tool Box??????

http://www.machinist-toolbox.com/

[dpuch]

The original tape reader on the CNC machine, does it perhaps have a rs232 interface? If the reader still owrks, just plug it into another control, or computer to capture the tape data.

Dale