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Punched Paper Tape Format

Les K

Plastic
Joined
Dec 2, 2005
Location
Lafayette, Indiana
Does anyone know of a source for documentation on the format of punched paper tape for various machine manufacturers? (ie. Warner&Swasey, Cincinnati Milicron, SunStrand ....) I have several machines of these types with executive paper tapes that are in bad condition. I would like to write software to read those tapes, varify the data against the specified format (checksums, parity, block length, leader length and etc.) and punch a new tape to replace them.

Les
 
There are really only two formats, EIA and ASCII. I have a table listed on one of the TTYs but I may have a scan somewhere.

If you have 2 teletypes, you can read the tape on one and punch a new one (mylar perhaps) on the second one.
 
I believe EIA and ASCII are coding sysetms for individual characters on the tape. The individual characters are usually grouped (blocked) in some formatting scheme to allow the control to detect read errors beyond simple parity errors and sometime allow the control to rewind a tape to the start of a block to re-read a bad block or even correct some errors through the use hashing codes.

Les
 
Hi Les,

A Google search for
"punched paper tape" "cincinnati milacron" format
yielded two PDF documents. I didn't download them.

Paper tapes are normally done in either 5-level or 7-level coding, possibly with a parity bit. Read errors are rare, and usually due to a reader problem, rather than a problem with the tape itself.
 
We've had some experience duplicating "Exec" tapes for Cincinnatis as well as old Fanuc 200s. Exec tapes must be read and punched in pure binary, where any individual character on the tape can range from 0 to 255 binary (no holes to 8 holes across). Other types of ASCII or EIA tapes can be read and saved as normal ASCII characters.

We would always read the old Exec tape until we got a perfect binary match at least 3 times to avoid errors. When you save these files on a computer disk, you must also save them as binary files so your software does not mistake a binary 26 for an end-of-file marker on the disk file. When punching a copy of the tape, you must likewise read and punch in pure binary.

You can tell by looking at a paper tape what the coding is.

An EIA RS244 coded tape always has an odd number of holes across the tape (each character has either 1, 3, 5, or 7 holes across. Channel 8 is only used for the EOB code, which always just has one hole in channel 8

ASCII No parity tapes can have even or odd numbers of holes across, but channel 8 is never punched.

ASCII Even parity tapes always have even numbers of holes across, and all 8 channels are used.

ASCII Odd parity (rarely used) always has odd numbers of holes across, and all 8 channels are used.

A binary "Exec" tape can have any combination of holes (across the tape). All 8 channels are used for data, and some characters have even numbers of holes across and some characters have odd numbers of holes.

Our PC-DNC Editor software can read and punch all these tape codes, (including binary) but you must be certain that your tape punch/reader is configured to use 8 data bits and no parity, otherwise the binary tapes are saved as ASCII, and that won't be an accurate copy.
 
I have an older Mitsubishi wire edm that you have to use tape to load the system software into the control.

I wonder, and after reading Dan's comments, would there be a way that you could get the paper tape converted to a floppy disc, and download it to the control via the RS-232 port?

To avoid dealing with the paper tape, that would be great, but could it be done very easily, or has anyone did this sort of thing before?

I would like to get something figured out, so that I would have more than one copy of the tapes, as if my tapes get damaged, I'm pretty much done, as you have to pay $2500 to Mitsubishi to have the privilege of buying a new set, even if they are available. And the machine won't work at all till you load the software.
 
I have used a greco box to load executive in a pratt and whitney starturn, when the greco is setup and cabled properly the machine doesnt know there isnt a tape reader on the other end of the wire. I also used the greco to run paper and mylar executives and programs onto floppy.

Bill
 
Hi Bill, Interesting, thanks for the reply. I have heard of the grecos before, but I think that they may be for machines that don't have the RS-232 port available-I think that you just hook up the end of the cable that goes to the tape reader to the greco, right?

In my case, the machine originally didn't come with the RS-232 port. It is a Mitsubishi retrofit on it-it seems like the same function as the greco-the cable from the CNC (That orginally went to the tape reader) hooks to the RS-232 board, and then the cable to the tape reader hooks to the board, and there is a switch so you can switch between your computer, and tape reader inputs.

So the question would turn to, can a pc hooked up to the CNC via the RS-232 port have the same function as the greco? (Ability to load control tapes) If so how? What kind of software would be needed on the pc to do so? And of course there is the question of getting the tape changed into a format that you can load into the pc, and then use the pc to load the software into the control.
 
Machinery_E: You can use a BTR (Behind the Tape Reader) link for that. We've connected a lot of old CNCs with BTR devices of one kind or another.

The older Fanuc and Yasnac controls use a tape reader with 5V TTL signals, so it's possible to connect them directly to the parallel printer (LPT) port on a PC, then use trick software to "fake out" the tape reader. Other CNC types with non-TTL signals can use a BTR board, like those made by ADR corporation. The board replaces your tape reader, and also has on-board memory and a serial port that you connect to your PC.

If you get the make & model of your CNC control, and also the model of your tape reader, you can call my buddy John Hosmon at Refresh Your Memory, Inc. (www.rym.com or [email protected]). He'll quote you either the direct BTR link or the ADR board with some software to send it binary files.

Of course, you'll still have to get your old Exec tape read in to the PC using a paper tape punch/reader, but we could do that for you as a service if you can't do it yourself. Once you have the binary file and the BTR link, you're finished with paper tapes forever.
 
Oops. I should have read your post more carefully. You apparently already have a BTR board of some kind, which should do the trick.

All you should need is some kind of DNC software that can read & send binary files and also read & send ASCII files for your part programs. Try our PC-DNC Editor for that. There's a free 30-day trial copy on our website at:

http://www.sub-soft.com/download/Editor_demo/setup_editor_3.4.0.exe

Make sure that your BTR board's serial port is configured to use 8 data bits and NO parity (most are) otherwise the binary Exec tapes won't read into the CNC correctly. PC-DNC Editor automatically uses 8 data bits and no parity when reading or sending binary files.
 
Well to me the greco seemed to be for many things, they do support interface with any kind of machine, the P&W had a parallal port interface, and I'm told they are not necc compliant with current PPort protocol, and that can fry a computer. I'm not up enough on the issue to know if a PC can run a tape reader or not (to read in paper and mylar tape programs), the greco is setup to do that. They sure are not cheap thats for sure. Even the RS232 on some fanuc is not the same pinouts as a computer rs232, if you wire them "right" they will not work in my experience, but wired to suit the fanuc or other we were able to send programs in and out fine, even "print" to the serial port with Norton Commander and have an ascii program go into the machine fine.

Bill
 
Dan, have you had any experience in fixing bad tapes? My original post was aimed at creatinig a system that could take a tape that has been damaged and automatically read and correct data read from a damaged tape. I believe this can be done. That is the reason for wanting the original manufacturers format for storing data on paper tape. After reading and correcting the data, it could be checked against the storage format as an additional check of correctness. I am sure most tapes have some form of checksums on the tapes that allow the control to determing if it has read the tape correctly. Beyond parity that is the most basic form of error detection in all electronic data storage and retrieval. I don't think this can be done with your standard off the shelf tape reader without making a few modifications to it.

What are your thought?

Thanks you all the replies to my post.

Les
 
I find it interesting to know what all these com settings were based on originally.

So you guys running these tape machines, are these controls real antiques, but on machines that are still productive but expensive to replace, or what is the story? I thought when I started out with a Bandit, that I was near prehistoric, but I never had to deal with tapes.
 
Les K: I don't think these Exec tapes use any form of error correction protocol.

It's always been my belief that there's a small "bootstrap loader" program at the beginning of the tape, which is the software the CNC needs to read the rest of the tape. After that, the bootstrap loader program in the CNC starts and reads in the binary data. From what I've seen of these tapes, there may be a checksum, but it won't help you "fix" a bad spot in the tape. It will just tell you that it didn't read correctly.

On the old Fanuc 200s that I used to work on, a questionable Exec tape might read in several times before it let the control run normally. I've never heard of a way to fix damaged tapes, other than useing the old manual splicing techniques with stickers and tape and such.

If your tape is obviously torn or has buggered-up holes, it can be fixed manually. If the damage is too extensive repair manually, you may just have to spring for another tape.

You may find someone on this forum with an identical machine who would let you "borrow" an Exec tape for reproduction.
 
Thats true, a checksum will not help fix a tape, however it would help indicate that the reproduction does match the original format. That is a thought about manually repairing a tape. On the other hand what is the time and effort worth to go through a few hundred feet of tape manually looking for the bad spot that is not allowing the load properly. I have had a machine down for several days because the exec would not load due to the condition of the tape. If it were as easy as just manually fixing the tape, would anyone spend the $2500 to purchase a new tape. Why not just manually fix the old one and have it duplicated?

On the subject of checksums or other means of checking what was read off a tape, I couldn't imagine a machine tool manufacturer building a control that would read an exec with no form of error checking. This could lead to catastrophic failures or distruction if a tape were improperly read. Checksums are easy to generate. A bootstrap loader of a few hundred bytes could have the intelligence to generate and test a checksum.

This discussion if very good food for thought. The result may be that I will find that it is not worth effort of creating such a system.

Thanks
Les
 
Les,
The difference here is checksum and error correction. The Checkksum can detect a bad load, and prevent running with a bad load. -Correcting- the bad bits is a little more complicated, and not as likely to have been implemented.
As Dan mentioned, he was not aware of error correction on an exec, just checksum to -detect- an error.
Correcting errors after they occur is a whole science.
Pete
 
Great timing, this thread.

Machinery_E,

I am in the same boat with you, 'cept my situation is a 1983 Sharnoa controller on a Wells Index mill. Got to feed the executive tape in and then can use an RS232 to upload/download to/from a PC. Have only one master tape and have not been able to locate another, or for that matter, anyone who knows what I'm talking about <lol>

I just purchased a tape reader/(hopefully)editor from MebFab in the free classified section (but the thread has disappeared from some strange reason) and some surplus tape from Toolbert.

My intent is to be able to put the exec tape on a floppy and then load directly into the controller from the PC. If it works, I'll be posting the results. Be happy to help you (or anyone else for that matter) out. I know what it's like to live in fear of losing that one tape


Damon,
If you're still reading, I left a post to you on the thread that disappeared offering my assistance, if I can help with your situation.

Mark
 
hmmm can't seem to edit, so I'll make another post:

HuFlung,
In my opinion, they are definitely dinosaurs. However, machines equipped with them are reasonably priced because a lot of people don't want to deal with the hassle and problems created by tapes. Some of the machines they are attached to are very well worth the money (good old American made iron) When the money is right, I hope to be moving out of the stone age myself one day, with either upgraded controllers or new machines altogether.

Mark
 
I know the P&W Starturn we used was worth the effort, in fact the screen pooped out and he had them come out and add a true CRT, at that time we had to have a new exec tape made. It was, and probably still IS a massive machine that is a true example of the art of american made machines.

The K&T 800 we had at one job you had to run a short bootstrap tape first, then load the exec. Once again an american machine fron the golden age, a true piece of art in my opinion...the pallet interchange apparatus probably outweighs the OKK VMC80 HMC we have in my present job..........you can look at one of these kinds of machines for hours if you have an ex potheads fascination for detail, I would gusss there is a solid MILE of welds in one at least.
 
This is a interesting thread! Thanks guys for answering my questions.

To Dan:
Thank you for the detailed responses! Yes, what I have is, I believe a BTR, "special" Mitsubishi.
It can be for several different configurations, depending on the computer/and software hooked up to it, for example, the number of data bits can be 5,6,7 or 8, parity, or no parity, etc., so it does seem pretty flexible, and hopefully it won't be too much of a problem to get going.
Thanks also for the link to you software, I will keep it in mind, as I don't have the machine where it needs to go (waiting for a good day to move out of one building to another) and then, we'll have to see what we can get into. The software consists of 5 tapes, four of them aren't bad at all, but the one is massive, about six inches in diameter. Unfortunatlety, my machine doesn't have a winder on it, so I end up with a huge pile of tape on the floor, with me cringing that it might get bent or ripped in the wrong way.

The only thing I'm not sure about is if I could use the reader to read the software tapes and then send them to the computer. I'll have to see when I get it going.

To Mark:
Interesting, I would be very interested in what happens with your Wells Index controller. I'm thinking thats what I might need-the reader/punch to get the tapes on floppies if I can't do it on the controller. I'll be keeping you and Dan in mind if I need to go that route.


By the way Mark, are you the one that worked at IBM in New York? I seem to remember reading that you worked there and ran '84 Mits. wire edms, so what I have might be right up your alley, as my machines are both from 1984.


Eric
 








 
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