From inwap@best.com Thu Dec 7 03:32:23 PST 2000 Article: 2186 of alt.sys.pdp10 Path: nntp1.ba.best.com!inwap From: inwap@best.com (Joe Smith) Newsgroups: alt.sys.pdp10 Subject: Re: TU45... Date: 7 Dec 2000 11:30:53 GMT Organization: Chez Inwap Lines: 67 Message-ID: <90nsdd$24la$1@nntp1.ba.best.com> References: <3A2C05A9.EBB63F46@srv.net> NNTP-Posting-Host: shell3.ba.best.com X-Trace: nntp1.ba.best.com 976188653 70314 206.184.139.134 (7 Dec 2000 11:30:53 GMT) X-Complaints-To: abuse@best.com NNTP-Posting-Date: 7 Dec 2000 11:30:53 GMT Xref: nntp1.ba.best.com alt.sys.pdp10:2186 In article , Daniel Seagraves wrote: >On Mon, 4 Dec 2000, Kevin Handy wrote: Nice drawing, let me add to it a bit. +-----------------+ | __ ___ | | | |\ / \ | 1 > Source reel | |3T| \ | 1 | | 2 > Takeup reel | | | \_\___/ | 3 > Vacuum columns. Open at top and bottom. | | | | 4 > Heads. | |==| ___ | 5 > Capstan | | | / \ | |*| | /| 2 | | |4|3B| / \___/ | | |__|/ | |_*5______________| 3T and 3B are two independent vacuum columns (top and bottom), and "==" signifies the barrier between the two. 5 is the capstan that moved the tape. When mounting a tape, a few feet are pulled off of (1), placed over 3T, between the two halves of 4, underneath 5 and 3B, then onto (2). There is no tape inside the vacuum at this point. When the LOAD sequence was started, the supply reel (1) would weakly attempt to rotate counterclockwise, taking up slack. The takeup reel (2) would rotate slowly clockwise. The voltage being fed into the takeup reel motor is higher than what is going into the supply reel motor. The supply reel loses the tug-of-war, and is forced to rotate clockwise slowly. About 1 or 2 additional feet of tape are drawn out of the supply reel before vacuum is established. During this time, the blowers creating the vacuum get up to speed and suck the tape into the vacuum columns with a slurping sound. Once the tape loops have stabilized inside the vacuum columns, the drive goes into search-forward-for-BOT mode. In this mode, the supply reel motor is still making a weak attempt to rotate counterclockwise, but is overpowered by the capstan moving the tape forward. The takeup reel motor is weakly tying to rotate clockwise, and is succeeding, taking up all the tape that the capstan is pushing at it. The tape moves quickly forward until BOT is reached. As you can imagine, this battle of weakly attempting to rotate one way while being forced to rotate the opposite direction by the other reel is something that has to be properly adjusted. IIRC there are 6 potentiometers on the TU45 that have to be adjusted. Daniel, Just before pressing the LOAD button, is the tape taut? Do the two reels rotate the right direction before vacuum is established? Here's what I did when loading a TU45: Put tape on supply reel. Unwind tape until the end was 2 inches off of the floor. Put the tape over the top vacuum column, between the heads and the head guide, under the capstan, over the top of the takeup reel. Insert finger into hole in takeup reel to hold tape against the hub, then turn the takeup reel two revolutions. Extract finger. Press LOAD. Watch take-up reel win tug-of-war. Hear the SLURP and watch tape run forward. As soon as BOT/LOAD-POINT light came one, press ON-LINE. -Joe -- See http://www.inwap.com/ for PDP-10 and "ReBoot" pages. From pechter@i4got.pechter.dyndns.org Thu Dec 7 23:20:12 PST 2000 Article: 2204 of alt.sys.pdp10 Path: nntp1.ba.best.com!news1.best.com!newsfeed.mathworks.com!nntp-out.monmouth.com!newspeer.monmouth.com!news.monmouth.com!not-for-mail From: pechter@i4got.pechter.dyndns.org (Bill Pechter) Newsgroups: alt.sys.pdp10 Subject: Re: TU45... Date: 7 Dec 2000 16:09:50 -0500 Organization: Unknown Lines: 91 Message-ID: <90ouau$cuv$1@i4got.pechter.dyndns.org> References: <3A2D0378.B5F07323@bartek.net> <90nnlk$932$2@bob.news.rcn.net> NNTP-Posting-Host: bg-tc-ppp592.monmouth.com Xref: nntp1.ba.best.com alt.sys.pdp10:2204 In article <90nnlk$932$2@bob.news.rcn.net>, wrote: > "D. R. Banks" wrote: >>Out of respect for everything that's decent, let's not say "TU7n." >> >>TU70s TU71s and TU72s came from Storage Technology Corp. TU78s came from >>garbage manufacturers. > >Yes, I did not mean to include the third shittiest magtape we made. >Thanks for the correction :-). > > >/BAH Hate to disagree with you Barb, but hardware's my old expertise. (Mostly PDP11's and Vaxen -- but I got to fix TU45's and TU77's and TU78's on KLs when the LCG Field Service guys needed tape expertise. The worst magtape made by DEC was the Tape Stretcher-11. The second worst was the TU10 -- DEC's first 10 inch tape design. The next was the TU16. The TE16 was reliable as hell and just as slow. DEC finally learned to buy decent tape drives with the Keystone drives they got from CDC/LaserMagnetics (LMSI). These became the TU80/81/TA8x. They were cheap and reliable. The only drives that DEC should've considerd were the HP88700 (I think that's the name) series of front loading drives. The TU45/70/78's were bastard children. Half DEC -- well, mostly Pertec. The TU45/77/78 tape transports were all Pertec designs (with some Dec engineering mods to "increase" reliablility. Like they did on the DataProducts printers). The TU45 was originally coming out of special systems as a stopgap for the PDP10 line of machines which needed a limited number of drives in a price range between the TU/TE16's and the TU77's which were in design at Pertec.) According to my old DEC tape instructor -- Pertec had to pull almost all it's tape engineers off the TU77 to fix the 45. I was told it was like two more years to get them fixed. DEC planned to sell less than 200 TU45's -- but they did thousands. And fixed 'em, again and again. My two favorites caught fire on me while working on 'em. The other two on the site were still running in '86 when I last heard of them. They were pretty much abandonned in place on line for the pair of dual ported TU77's and the TU78 at the site. The TU45's split vacuum column and the tricky tach designs and tape path caused no end of load problems and adjustment issues. Any defects and scallopped edges in the tape caused a vaccum drop. The TU45 was supposedly Pertec's first vacuum drive (it shows) and the prints are very closely based off their earlier tension arm designs. The TU77 and TU78 and TU45 had DEC designed formatters to allow them to interface to the Pattented DEC MassBus. The formatter for the TU77 and TU45 was the TM03 (an ok device -- but nothing special...) The whiz bang toy was the TM78 which had more bells and whistles than almost any DEC controller I've ever seen. The Tape Stretcher-11 has the problem (in non-ECO'd versions) of being the worst DEC tape drive to load (it's brakes are on during the load sequence making it a bitch to load). It also used triacs in the motor control circuitry which could kick on by electrical noise on it's power lines. This caused both motors to go on in full speed mode in opposite directions. This stretched the tape -- destroying all data -- and leaving it wrapped around the reel with the strongest motor. Hence, the name. By 1984 the ECO's (total new firmware -- about 10 roms) a dead-bug glued chip on the back of the control board and some nice fat coils in line with the motors for noise rejection) removed the break effect at load time and eliminated the problem with the AC noise motor-on. I did a number of these ECO's... The TS11 goes down as DEC's worst tape drive. The DECtape was it's only real good one. Bill -- -- bpechter@monmouth.com | FreeBSD since 1.0.2, Linux since 0.99.10 | Unix Sys Admin since Sys V/BSD 4.2 | Windows System Administration: "Magical Misery Tour" From eric-no-spam-for-me@brouhaha.com Thu Dec 7 23:23:11 PST 2000 Article: 2216 of alt.sys.pdp10 Sender: eric@ruckus.brouhaha.com From: Eric Smith Newsgroups: alt.sys.pdp10 Subject: Re: For Tim, 166 emulator please References: <90ltti$bub$1@spies.com> <87n1e8bquq.fsf@k9.prep.synonet.com> X-Disclaimer: Everything I write is false. Organization: Eric Conspiracy Secret Labs X-Eric-Conspiracy: There is no conspiracy. Date: 07 Dec 2000 14:45:35 -0800 Message-ID: Lines: 19 X-Newsreader: Gnus v5.7/Emacs 20.7 NNTP-Posting-Host: ruckus.brouhaha.com X-Trace: 7 Dec 2000 14:48:33 -0800, ruckus.brouhaha.com Path: nntp1.ba.best.com!news2.best.com!news.maxwell.syr.edu!HSNX.atgi.net!news.kjsl.com!news.spies.com!ruckus.brouhaha.com Xref: nntp1.ba.best.com alt.sys.pdp10:2216 Greg Satz writes: > I have the HP 88780 on order including the SCSI adapter to use it. I > also asked for any "programmers" documentation just in case as I am not > sure what I will do if the tapes have errors on them. > > What is the easiest way to make a TPC format file under Unix? TPC files are annoying because you can't efficiently backspace when using them on a simulator. I use John Wilson's format, which has a record length both before and after the record. Supnik's simulators for other PDP's support this, and I've hacked it into Stu Grossman's KX10. A Linux program I use with an HP 88780 is available at: http://www.36bit.org/dec/software/unix-util/ It should be easy to convert Wilson format tape images to/from TPC, but I'm not aware of any existing code to do it. From shoppa@trailing-edge.com Thu Dec 7 23:23:25 PST 2000 Article: 2219 of alt.sys.pdp10 Path: nntp1.ba.best.com!news2.best.com!news.maxwell.syr.edu!wn4feed!worldnet.att.net!198.6.0.213!uunet!ffx.uu.net!spool1.news.uu.net!spool0.news.uu.net!reader3.news.uu.net!not-for-mail Message-ID: <3A2FD6BA.6DBA4FB1@trailing-edge.com> Date: Thu, 07 Dec 2000 18:28:10 -0400 From: Tim Shoppa Organization: Trailing Edge Technology X-Mailer: Mozilla 3.03Gold (X11; I; OpenVMS V7.2 AlphaServer 1200 5/533 4MB) MIME-Version: 1.0 Newsgroups: alt.sys.pdp10 Subject: Re: For Tim, 166 emulator please References: <90ltti$bub$1@spies.com> <87n1e8bquq.fsf@k9.prep.synonet.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 9 NNTP-Posting-Host: 63.73.218.130 X-Trace: reader3.news.uu.net 976231691 8962 63.73.218.130 Xref: nntp1.ba.best.com alt.sys.pdp10:2219 Eric Smith wrote: > It should be easy to convert Wilson format tape images to/from TPC, > but I'm not aware of any existing code to do it. The Supnik simulator package comes with such a tool, under the name "mtcvtv23" (so-called because the Supnik simulators prior to V2.3 used the far-more-common-in-archives TPC format.) Tim. From sword7@speakeasy.org Thu Dec 7 23:23:58 PST 2000 Article: 2223 of alt.sys.pdp10 Path: nntp1.ba.best.com!news1.best.com!newsfeed.mathworks.com!portc01.blue.aol.com!cyclone2.usenetserver.com!news-out.usenetserver.com!cyclone1.usenetserver.com!news-east.usenetserver.com.POSTED!not-for-mail Message-ID: <3A306031.62A67738@speakeasy.org> From: Timothy Stark X-Mailer: Mozilla 4.75 [en] (X11; U; Linux 2.2.16-22 i686) X-Accept-Language: en MIME-Version: 1.0 Newsgroups: alt.sys.pdp10 Subject: Re: For Tim, 166 emulator please References: <90ltti$bub$1@spies.com> <87n1e8bquq.fsf@k9.prep.synonet.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 30 X-Abuse-Info: Please be sure to forward a copy of ALL headers X-Abuse-Info: Otherwise we will be unable to process your complaint properly X-Complaints-To: abuse@webusenet.com NNTP-Posting-Date: Thu, 07 Dec 2000 23:09:49 EST Organization: WebUseNet Corp http://www.usenetserver.com - Home of the fastest NNTP servers on the Net. Date: Thu, 07 Dec 2000 23:14:41 -0500 Xref: nntp1.ba.best.com alt.sys.pdp10:2223 Eric Smith wrote: > TPC files are annoying because you can't efficiently backspace when > using them on a simulator. > > I use John Wilson's format, which has a record length both before > and after the record. Supnik's simulators for other PDP's support > this, and I've hacked it into Stu Grossman's KX10. > > A Linux program I use with an HP 88780 is available at: > http://www.36bit.org/dec/software/unix-util/ > > It should be easy to convert Wilson format tape images to/from TPC, > but I'm not aware of any existing code to do it. Eric: I looked into your archive site about tapeutils-0.6 stuffs. I downloaded and tried it. It worked so well for my Red Hat Linux 7 system! I had older copies of read20 and 10backup that is designed for tpc format did not work so well. Ok, I will convert my all tpc files that I downloaded >from Tim Shoppa's archives (everything ) to Wilson's tape format after I added Wilson's tape format to my emulator so that it can read Wilson's tape format files. Thank you for new tape utilities. -- Tim Stark