PLEX86  x86- Virtual Machine (VM) Program
 Plex86  |  CVS  |  Mailing List  |  Download  |  Computer Folklore

What's the most stablesafe minidrive USB Flash, SD Card, PCMCIA MicroDrive, other ...I don't want

VAX 4000 m500A problem
Jealous insofar that my 4000 m60 broke before I had the chance to locate an OpenVMS 7...

David Powell

I frequently used rolled oiled tape with high speed reader punches. The readers, at least were intended for fan fold tape and couldn't handle much "back pressure" on the feed without causing problems. With rolled tape, the best was was to carefully unroll the tape backwards into a large open box and place another large open box on the "downstream" side of the reader to catch the tape after it is read. Of course, you could just let it pile up on the floor but this was particularly ugly with oiled tape as it would pick up the dirt even quicker than non oiled tape. I had both oiled and non oiled roll tape but have never seen oiled fan fold tape so I don't know if it ever existed. I saw two types of feed mechanisms for HSR's, pinch roller and brake as well as a star wheel driven by a stepper motor. This latter was in a DEC unit on a PDP-8 in the mid 60's. It had a nasty habit of tearing out the feed holes in the tape if there was even the slightest back pressure on the feed source. The only problem I had with the pinch roller type (I still have a DG 6013 in my crawl space), was that if you used oiled tape the oil would pick up dirt and leave it as a sticky mess on the capstan andor pinch roller. If it wasn't regularly cleaned it would get so bad that replacing it seemed to be the only option which worked.

Another issue with oiled tape, yellow or gray, was that over time the oil would tend to come together and create a translucent area in the tape which a photo reader would see through even though there was no hole. As to high speed punches I only came across two makes, Facit and the famous Teletype BRPE. The latter was intended for use with oiled tape but was such a beast that it would work for a few years with unoiled tape before wearing out. I only saw unoiled fan fold used with the Facit and never read the manual on it. Although there were many different vendors of HSR's, at the center of many vendors HSP's was a BRPE. However, with "fancy" packaging you had to open it up to see that it was a BRPE. (BTW, BRPE is pronounced "burpee" :-)

As to dirt in data readers in general. I spent some time in China around 1990 with a DEC PDP-11 system with one of those TK50 magnetic tape cartridges. After having to rake the coal dust out of it each morning, we started relying on early laptop PC's and 3 1-2 inch floppies, using Kermit to get our files onto the PDP's hard drive. This approach proved much more reliable.

What's the most stablesafe minidrive USB Flash, SD Card, PCMCIA MicroDr
Patrick Scheible But I liked the 33 keyboard and got used to its rythm. If your finger got to a key before it was time to send the character...

Although the above description of using boxes for rolled paper tape on a high speed reader sounds ugly, there were a number of commercially made hand operated paper tape "spoolers" for quickly rolling up the tape from the box. I still have a couple laying around here somewhere. Real early on I saw and used some "main frame" HSR-P's. These had powered feed and take up spools complete with tension arms for automatic control, just like early computer magnetic tape drives. (Or the infamous DEC TS11 :-) The tape was on reels with NAB hubs. However, "mainframe" use of paper tape was dying just as I came along. I still have the maintenance manual for the HSR-P for the first mainframe computer I programmed (the one my .sig line comes from). In was in a wide full height cabinet styled to match the rest of the machine with the reader and its spools at the top and the punch (based on a BRPE) and its spools on the bottom. It could handle 5, 6, 7 or 8 level paper tape. The reader head in this unit was made by Digitronics. When I wanted to use it in the late 60's, it had been unused for several years and had been taken off of the maintenance contract. I had some work to do to "make it happy".

The midseventies SHARE survey
SHARE was-is the user group for IBM mainframe shops, and it dates from the OS-360 days. Some of its tapes of shared software mods are...
The midseventies SHARE survey 63
recent posting in comp.arch about personal computers my personal computer was 64kbyte 360-30 ... normally the university shutdown the computing center from 8am sat. until...


List | Previous | Next

What's the most stablesafe minidrive USB Flash, SD Card, PCMCIA MicroDr

Alt Folklore Computers Newsgroups

What's the most stablesafe minidrive USB Flash, SD Card, PCMCIA MicroDrive, other ...I don't want