Re: Restoring Old Paper Tape
on moldy paper and other items generally we will bag it and tag it to isolate it from everything else... check part # or document name ( in the case of printed material) against what already exists. if it exists then the moldy nasty stuff is scrap. If it is something that warrants preservation but not found elsewhere then we consider moving forward on preservation efforts. Ed Sharpe archivist for SMECC _www.smecc.org_ (http://www.smecc.org) In a message dated 1/21/2016 6:57:02 P.M. US Mountain Standard Time, silent...@gmail.com writes: I'm tossing this out here as a conversation-starter more than a request for help, although I may end up putting the knowledge to use. Today I received a set of original HP paper tapes for the 2115a machine. I don't know if they've been archived or not - there are dozens of HP tapes on bitsavers and I'll have to make a P/N list and compare them. The real problem is they're in horrible shape. Decades of basement moisture and likely a few critters have turned them blackened, moldy and stuck together. So, what to do? How to get to the data without a bio-hazardous payload along for the ride? My thoughts go toward sunlight and/or U/V light (like a hair salon sanitizer,) rubber gloves and a mask, isopropyl alcohol, careful picking apart of layers, etc. I'd think one thing in our favor is that holes in paper are going to be easier to read than ink on paper. So Part 1 is getting them into readable condition, with part 2 being the actual reading. Any experience out there? -j
Re: Restoring Old Paper Tape
> Did anyone get a schematic on the values the fellow used in the > article on vintage-computer.com? Not necessarily to squelch discussion of building optical readers, but the original question was more about archival preservation of tapes suffering from bad storage. I'd be interested in hearing how people have approached this problem in the past. In googling about yesterday, I noticed that libraries and archives are now at least occasionally using chlorine dioxide to deal with mold infestations. Wipes are commercially available for going after surfaces. There are also humidity-activated packets which produce a safe level of ClO2 gas over a period of a month or so, and are intended to "fumigate" an area. While they packets are a bit expensive, the mold apparently returns slowly enough that continuous treatment isn't necessary. Apparently ozone isn't considered very successful, and also damages bindings, so isn't used much any more. Now, the library and archival community has legitimate concerns about the long term life of the objects they're cleaning. Many in the ccmp hobbyist community seem concerned largely with extracting the data from the object once, and then largely ignoring the physical object. I wonder if we're being a bit callous here, so maybe that's an interesting topic for discussion too. Cheers, De
Re: Restoring Old Paper Tape
On 1/21/2016 10:48 PM, John Robertson wrote: On 01/21/2016 6:46 PM, Charles Anthony wrote: -- Charles Would it not be simpler to make an optical reader to handle this job? You need a light source and the correct number of opto transistors to read the light from each hole. There is an index built into the tape so that is easy to set. Something like this: http://hackaday.com/2014/05/02/reading-paper-tapes-from-scratch/ Did anyone get a schematic on the values the fellow used in the article on vintage-computer.com? I see the photos, but didn't see any schematic showing what the actual circuit he found to work was. Also didn't see any real names. Was the cited article anyone here? thanks Jim Of course my assumption above is based on tape that is still complete. If it has holes or can't be pulled then, yes, photographing and visually reading the dot patterns may be necessary, but that sounds rather impractical if there are more than a couple of tapes to transcribe. John :-#)#
Re: Restoring Old Paper Tape
Did you guys forget the Oliver Engineering tape reader? Heres a construction article from Herb: http://www.retrotechnology.com/herbs_stuff/s_paper.html From: cctalk on behalf of Charles Anthony Sent: Friday, January 22, 2016 8:27 AM To: j...@flippers.com; General Discussion: On-Topic and Off-Topic Posts Subject: Re: Restoring Old Paper Tape On Thu, Jan 21, 2016 at 10:48 PM, John Robertson wrote: > >> Would it not be simpler to make an optical reader to handle this job? > You need a light source and the correct number of opto transistors to read > the light from each hole. There is an index built into the tape so that is > easy to set. > > Something like this: > > http://hackaday.com/2014/05/02/reading-paper-tapes-from-scratch/ > > Of course my assumption above is based on tape that is still complete. If > it has holes or can't be pulled then, yes, photographing and visually > reading the dot patterns may be necessary, but that sounds rather > impractical if there are more than a couple of tapes to transcribe. This is the approach I would use, based on my skill set. I have mad s/w skillz, but building something more complicated than Legos is just beyond me. Also, given the described condition of the tapes, this is the approach least likely (it seems to me) to make things worse. YMMV. -- Charles
Re: Restoring Old Paper Tape
On Thu, Jan 21, 2016 at 10:48 PM, John Robertson wrote: > >> Would it not be simpler to make an optical reader to handle this job? > You need a light source and the correct number of opto transistors to read > the light from each hole. There is an index built into the tape so that is > easy to set. > > Something like this: > > http://hackaday.com/2014/05/02/reading-paper-tapes-from-scratch/ > > Of course my assumption above is based on tape that is still complete. If > it has holes or can't be pulled then, yes, photographing and visually > reading the dot patterns may be necessary, but that sounds rather > impractical if there are more than a couple of tapes to transcribe. This is the approach I would use, based on my skill set. I have mad s/w skillz, but building something more complicated than Legos is just beyond me. Also, given the described condition of the tapes, this is the approach least likely (it seems to me) to make things worse. YMMV. -- Charles
Re: Restoring Old Paper Tape
Another option is something like an op-80a where you can manually pull the tape across sensors making sure you don't damage it. Essentially a low tech version of what you guys described using a video camera. The op-80a doesn't have a physical sprocket to break the tape, it uses the sprocket holes only for timing/triggering the character. Even if you don't have access to an one, they can be built pretty easily and the schematic is readily available on line. I keep one around just for such a purpose, though I really should put a microcontroller together to bit bang the parallel to serial or a simple UART so that I can hook it up to a modern computer. It would remove the middle step of reading it into my sol-20 and then dumping it to my laptop. Cheers, Corey corey cohen uǝɥoɔ ʎǝɹoɔ > On Jan 21, 2016, at 9:46 PM, Charles Anthony > wrote: > >> On Thu, Jan 21, 2016 at 6:21 PM, Jason T wrote: >> >> On Thu, Jan 21, 2016 at 8:04 PM, Charles Anthony >> wrote: >>> For part 2, personally, I would take movies of the paper tape moving and >>> doing image analysis to recover that data; this occurs to me because I've >>> done a fair bit of image recognition software, so this solution may not >> be >>> feasible for all. If you sent me a sample movie, I would make a stab at >>> writing some data recovery software. >> >> I have heard of those approach and was thinking it may be a solution >> in cases where the tape is too fragile (and that's pretty likely >> here.) It would be well beyond my abilities but might make an >> interesting project for you or anyone else with the skills. > > > The general approach would be to have the tape backlit (on a piece of > glass, with a light source and and diffuser underneath ) and guide block > that the tape slides against so the holes move left-to-right but not up and > down. The camera is set up so that the tape fills the image as much as is > feasible. You start the camera, and slide the tape. Constant speed is not > important, but avoid backing up. > > Grab a frame from the movie. Figure out the approximate pixel coordinates > of the data and pin feed holes in the axis moving across the tape (eg, the > 1 bit is about 24 pixels from the top of the image, the 2 bit is about 47 > pixels from the top, etc). > > Process the movie a frame at a time. Grab a column of pixels from the > center of the image from top to bottom. Look at the pixels around where the > pin feed is, decide if they are light or dark. If light, the a character is > centered in the column. If not, move to the next frame. look at the pixels > around where each data bit is, and decide if the are light (punched) or > dark (unpunched). Write out that data. Skip frames until the pin feed > pixels go dark, and then skip frames until it goes light again; that will > be the next character. Repeat. > > The pin feed holes greatly simplify the process. This process is quite > analogous to reading multi-track magnetic media with a timing track. > > Test on a known tape. Debug. Run over damaged tapes; data recovered. > > -- Charles
Re: Restoring Old Paper Tape
On 01/21/2016 6:46 PM, Charles Anthony wrote: On Thu, Jan 21, 2016 at 6:21 PM, Jason T wrote: On Thu, Jan 21, 2016 at 8:04 PM, Charles Anthony wrote: For part 2, personally, I would take movies of the paper tape moving and doing image analysis to recover that data; this occurs to me because I've done a fair bit of image recognition software, so this solution may not be feasible for all. If you sent me a sample movie, I would make a stab at writing some data recovery software. I have heard of those approach and was thinking it may be a solution in cases where the tape is too fragile (and that's pretty likely here.) It would be well beyond my abilities but might make an interesting project for you or anyone else with the skills. The general approach would be to have the tape backlit (on a piece of glass, with a light source and and diffuser underneath ) and guide block that the tape slides against so the holes move left-to-right but not up and down. The camera is set up so that the tape fills the image as much as is feasible. You start the camera, and slide the tape. Constant speed is not important, but avoid backing up. Grab a frame from the movie. Figure out the approximate pixel coordinates of the data and pin feed holes in the axis moving across the tape (eg, the 1 bit is about 24 pixels from the top of the image, the 2 bit is about 47 pixels from the top, etc). Process the movie a frame at a time. Grab a column of pixels from the center of the image from top to bottom. Look at the pixels around where the pin feed is, decide if they are light or dark. If light, the a character is centered in the column. If not, move to the next frame. look at the pixels around where each data bit is, and decide if the are light (punched) or dark (unpunched). Write out that data. Skip frames until the pin feed pixels go dark, and then skip frames until it goes light again; that will be the next character. Repeat. The pin feed holes greatly simplify the process. This process is quite analogous to reading multi-track magnetic media with a timing track. Test on a known tape. Debug. Run over damaged tapes; data recovered. -- Charles Would it not be simpler to make an optical reader to handle this job? You need a light source and the correct number of opto transistors to read the light from each hole. There is an index built into the tape so that is easy to set. Something like this: http://hackaday.com/2014/05/02/reading-paper-tapes-from-scratch/ Of course my assumption above is based on tape that is still complete. If it has holes or can't be pulled then, yes, photographing and visually reading the dot patterns may be necessary, but that sounds rather impractical if there are more than a couple of tapes to transcribe. John :-#)# -- John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames) www.flippers.com "Old pinballers never die, they just flip out"
RE: Restoring Old Paper Tape
By all means, let's discuss and it will be a useful and fascinating conversation both now and in the future. But just as a thought for the more immediate issue (your tapes)... I find it somewhat unlikely that a significant number of early HP 21XX paper tapes are not already archived, or in good condition elsewhere. So at least regarding your particular stash of tapes, I'd suggest first getting a list up of what all you have. At the least, you may find machine readable images already exist, or that of all your tapes there's only 3 that should be given heroic efforts There's a major percentage of those tapes online, and I have a pretty huge (cases and cases) stash of early 2114/5/6 & 2100 tapes I haven't even cataloged yet. I should do the same, but at least mine are all (currently) in pristine shape :) J
Re: Restoring Old Paper Tape
On Thu, Jan 21, 2016 at 6:21 PM, Jason T wrote: > On Thu, Jan 21, 2016 at 8:04 PM, Charles Anthony > wrote: > > For part 2, personally, I would take movies of the paper tape moving and > > doing image analysis to recover that data; this occurs to me because I've > > done a fair bit of image recognition software, so this solution may not > be > > feasible for all. If you sent me a sample movie, I would make a stab at > > writing some data recovery software. > > I have heard of those approach and was thinking it may be a solution > in cases where the tape is too fragile (and that's pretty likely > here.) It would be well beyond my abilities but might make an > interesting project for you or anyone else with the skills. > The general approach would be to have the tape backlit (on a piece of glass, with a light source and and diffuser underneath ) and guide block that the tape slides against so the holes move left-to-right but not up and down. The camera is set up so that the tape fills the image as much as is feasible. You start the camera, and slide the tape. Constant speed is not important, but avoid backing up. Grab a frame from the movie. Figure out the approximate pixel coordinates of the data and pin feed holes in the axis moving across the tape (eg, the 1 bit is about 24 pixels from the top of the image, the 2 bit is about 47 pixels from the top, etc). Process the movie a frame at a time. Grab a column of pixels from the center of the image from top to bottom. Look at the pixels around where the pin feed is, decide if they are light or dark. If light, the a character is centered in the column. If not, move to the next frame. look at the pixels around where each data bit is, and decide if the are light (punched) or dark (unpunched). Write out that data. Skip frames until the pin feed pixels go dark, and then skip frames until it goes light again; that will be the next character. Repeat. The pin feed holes greatly simplify the process. This process is quite analogous to reading multi-track magnetic media with a timing track. Test on a known tape. Debug. Run over damaged tapes; data recovered. -- Charles
Re: Restoring Old Paper Tape
On Thu, Jan 21, 2016 at 8:04 PM, Charles Anthony wrote: > For part 2, personally, I would take movies of the paper tape moving and > doing image analysis to recover that data; this occurs to me because I've > done a fair bit of image recognition software, so this solution may not be > feasible for all. If you sent me a sample movie, I would make a stab at > writing some data recovery software. I have heard of those approach and was thinking it may be a solution in cases where the tape is too fragile (and that's pretty likely here.) It would be well beyond my abilities but might make an interesting project for you or anyone else with the skills.
Re: Restoring Old Paper Tape
On Thu, Jan 21, 2016 at 5:56 PM, Jason T wrote: > I'm tossing this out here as a conversation-starter more than a > request for help, although I may end up putting the knowledge to use. > Today I received a set of original HP paper tapes for the 2115a > machine. I don't know if they've been archived or not - there are > dozens of HP tapes on bitsavers and I'll have to make a P/N list and > compare them. The real problem is they're in horrible shape. Decades > of basement moisture and likely a few critters have turned them > blackened, moldy and stuck together. > > So, what to do? How to get to the data without a bio-hazardous > payload along for the ride? My thoughts go toward sunlight and/or U/V > light (like a hair salon sanitizer,) rubber gloves and a mask, > isopropyl alcohol, careful picking apart of layers, etc. I'd think > one thing in our favor is that holes in paper are going to be easier > to read than ink on paper. So Part 1 is getting them into readable > condition, with part 2 being the actual reading. > > For part 2, personally, I would take movies of the paper tape moving and doing image analysis to recover that data; this occurs to me because I've done a fair bit of image recognition software, so this solution may not be feasible for all. If you sent me a sample movie, I would make a stab at writing some data recovery software. -- Charles
