Article 4362 of alt.sys.pdp10: Path: news3.best.com!news2.best.com!news1.best.com!peerfeed.ncal.verio.net!news.he.net!news.pagesat.net!decwrl!pa.dec.com!nntpd.lkg.dec.com!not-for-mail From: nospam@zk3.dec.com (Eric Werme - replace nospam with werme) Newsgroups: alt.sys.pdp10,alt.folklore.computers Subject: Re: What was the TOPS-10 DATE75 fix? Date: 10 Nov 1998 02:39:24 GMT Organization: Digital Equipment Corporation Lines: 86 Message-ID: <72890s$dft$1@nntpd.lkg.dec.com> References: <36444B15.2FBA1EA5@trailing-edge.com> Reply-To: (Replace nobody with werme) nobody@zk3.dec.com NNTP-Posting-Host: alingo.zk3.dec.com X-Newsreader: NN version 6.5.0 CURRENT #60 Xref: news3.best.com alt.sys.pdp10:4362 alt.folklore.computers:117381 Tim Shoppa writes: >This format broke on 4-Jan-1975, when the date representation >overflowed 4095 and no longer fit in 12 bits. I know that the >date was extended to 15 bits by the DATE75 patches, but I >don't know how these extra 3 bits fit into the TOPS-10 >DECTape format, or if they even did make it into the DECTape >format spec. Does anyone have a copy of the TOPS-10 DECTape >format spec that officially says where these three bits go? I don't have the official data, but I have code I used through 1978 in my TULIP documentation. (Tulip was a very nice I/O package that used user UUOs. The instructions below that start with W are Tulip Write instructions): 70 ;SYMBOLS WE NEED: 71 000000 DTA==0 ;IO CHANNEL FOR DECTAPE 72 000100 PDLLEN==100 ;LENGTH OF PUSHDOWN LIST 73 000200 DIRSIZ==200 ;SIZE OF DTA DIRECTORY BLOCK 74 000144 DIRADR==^D100 ;ADDRESS OF DIRECTORY BLOCK 75 000026 MAXFIL==^D22 ;MAX # OF FILES THAT WILL FIT ON A TAPE 76 001102 TAPLEN==^D578 ;# OF BLOCKS ON A DECTAPE 77 000000 DIRBYT==0 ;RELATIVE ADDR OF DIRECTORY BYTE MAP (5 BIT BYTES) 78 000123 DIRFIL==^D83 ;RELATIVE ADDR OF FIRST FILENAME 79 000151 DIREXT==^D105 ;RELATIVE ADDR OF EXTENSION/DATE WORD 80 000177 DIRLBL==^D127 ;RELATIVE ADDR OF LABEL WORD TULIP4 - VERSION 4(3) - PROGRAM 4 FOR TULIP MANUAL MACRO %50(272) 04:11 13-JAN-75 PAGE 17 EXAMPL MAC 11-JAN-75 00:12 RIC WERME, OCTOBER 1974 562 ;COLLECTED ALL THE DATA WE NEED, PRINT THE HEADER NOW 563 DISIX [[SIXBIT\D&IRECTORY %#&F&REE: % BLOCKS, % FILES#!\] 564 PUSHJ P,DATTIM;PRINT DIRECTORY HEADER. FIRST DATE AND TIME 565 WDEC FILSIZ ;THEN THE FREE BLOCKS 566 400072' 001 10 0 00 401002' WDEC FREFIL] ;AND THE FREE FILES 567 400073' 332 01 0 05 000177 SKIPE T1,DIRLBL(P1) ;DOES THIS TAPE HAVE A LABEL? 568 DISIX [[SIXBIT\T&APE &ID: %#!\] 569 400074' 001 10 0 00 401011' WNAME T1] 570 400075' 001 03 0 00 003212 W2CHI CRLF ;SEPARATE HEADER FROM DATA 571 572 400076' 200 01 0 00 000643' MOVE T1,FREFIL ;CHECK TO SEE IF ANY REASON TO PRINT 573 400077' 306 01 0 00 000026 CAIN T1,MAXFIL ; DIRECTORY. SAY EMPTY IF NO FILES WRITTEN 574 400100' 001 10 0 00 401017' ZERDIR: DISIX [CPOPJ##,,[SIXBIT\D&IRECTORY EMPTY###!\]] 575 400101' 201 04 0 00 000001 MOVEI T4,1 ;MAKE INDEX INTO FILSIZ FOR BLOCKS USED 576 ;NO NEED TO SAVE P1 NOW, USE IT AS AOBJN WORD 577 578 ;NOW PRINT OUT INFO FOR EACH FILE 579 400102' 336 00 0 05 000123 DIRLOP: SKIPN DIRFIL(P1) ;DOES THIS FILE EXIST? 580 400103' 254 00 0 00 400115' JRST DIRAOB ;NO, TRY NEXT 581 400104' 135 01 0 00 401020' LDB T1,[POINT 12,DIREXT(P1),35];GET LOW 12 BITS OF CREATION DATE 582 400105' 201 02 0 00 000001 MOVEI T2,1 ;CHECK THE BYTE MAP FOR THE TOP 3 BITS 583 400106' 612 02 0 05 000000 TDNE T2,DIRBYT(P1) 584 400107' 435 01 0 00 010000 IORI T1,1B23 ;BRING UPTO 1985 585 400110' 612 02 0 05 000026 TDNE T2,DIRBYT+MAXFIL(P1) 586 400111' 435 01 0 00 020000 IORI T1,1B22 ;UPTO 2007 587 400112' 612 02 0 05 000054 TDNE T2,DIRBYT+<2*MAXFIL>(P1) 588 400113' 435 01 0 00 040000 IORI T1,1B21 ;UPTO 2051 (FOR THE PDP-10 IN THE SMITHSONIAN) 589 DISIX [[SIXBIT\%.% % %#!\] 590 WSIX 6,DIRFIL(P1);FILE 591 WSIX 3,DIREXT(P1);AND EXTENSION 592 WDEC 3,FILSIZ(T4);THEN LENGTH 593 400114' 001 10 0 00 401023' PUSHJ P,DATTHN] ;AND CREATION DATE 594 400115' 201 04 0 04 000001 DIRAOB: MOVEI T4,1(T4) ;POINT TO NEXT FILE NUMBER 595 400116' 253 05 0 00 400102' AOBJN P1,DIRLOP ;AND LOOP FOR NEXT FILE 596 400117' 002 00 0 00 401030' DIRXIT: WSIX [SIXBIT\##!\] ;ADD A LITTLE SPACE 597 400120' 263 17 0 00 000000 POPJ P, ;OR RETURN WHEN DONE 886 ;SUBROUTINE TO PRINT EITHER CURRENT DATE (ENTER AT DATPRT) OR DATE 887 ;PASSED IN T1 (ENTER AT DATTHN). USES T1-T3 888 889 400400' 047 01 0 00 000014 DATPRT: DATE T1, ;GET TODAY'S DATE 890 400401' 231 01 0 00 000564 DATTHN: IDIVI T1,^D<12*31> ;T1_YEAR-64 891 400402' 231 02 0 00 000037 IDIVI T2,^D< 31> ;T2_MONTH-1, T3_DAY-1 892 400403' 004 02 0 03 000001 WDECI 2,1(T3) ;DAY 893 400404' 010 01 0 02 400447' WNAME MONTAB(T2) ;.MONTH. 894 400405' 004 00 0 01 000100 WDECI ^D64(T1) ;AND YEAR 895 400406' 263 17 0 00 000000 POPJ P, ;AND RETURN The above should be viewed in 132 column monospace, of course.... -Ric -- <> Eric (Ric) Werme <> The above is unlikely to contain <> <> ROT-13 addresses: <> official claims or policies of <> <> <> Compaq Computer Corp. <> <> <> http://www.cyberportal.net/werme <> Article 4744 of alt.sys.pdp10: Path: news3.best.com!nntp1.ba.best.com!not-for-mail From: inwap@best.com (Joe Smith) Newsgroups: alt.sys.pdp10 Subject: Re: need the date of Day 4096 Date: 5 Apr 1999 19:36:02 -0700 Organization: Chez Inwap Message-ID: <7ebrui$g49$1@shell3.ba.best.com> References: <37082c39.88427826@netnews.worldnet.att.net> Lines: 38 NNTP-Posting-Host: shell3.ba.best.com X-Trace: nntp1.ba.best.com 923366169 204 inwap@206.184.139.134 Xref: news3.best.com alt.sys.pdp10:4744 In article <37082c39.88427826@netnews.worldnet.att.net>, David M. Razler wrote: > >Exactly what day was it when the 12-bit date memory field expired requiring >the emergency fix? Method 1: 4096 divided by 31 = 132 with a remainder of 4. (item "A) 132 divided by 12 = 11 with a remainder of 0. (items "B" and "C") C: year = 11 + 1964 = 1975 B: month = 0 + 1 = January A: day = 4 + 1 = 5th Method 2: 4096 divided by (12*31) = 11 with a remainder of 4, therefore 11th year. 4 divided by 31 = 0 with a remainder of 4, therefore 1st month, 5th day. The date format was designed to be easy to determine on machine that had the integer divide instruction implemented in hardware. The hardware that implemented LDB and DPB (load and deposit byte instructions) was (theoretically) optional. TOPS-20 uses a date format that allows elapsed time to be calculated by simply subtracting two date numbers. The same cannot be said of the TOPS-10 12-bit or 15-bit date fields. Later versions of TOPS-10 used the 18+18 bit format internally, where the left halfword was incremented once a day, and the right half was a fraction of a day that was calculated once a second (but incremented by approximately 3 counts per second). -Joe -- INWAP.COM is Joe Smith, Sally Smith and our cat Murdock. (The O'Hallorans and their cats moved to http://www.tyedye.org/ Nov-98.) See http://www.inwap.com/ for PDP-10, "ReBoot", "Shadow Raiders"/"War Planets" Article 4756 of alt.sys.pdp10: Path: news3.best.com!news2.best.com!newsfeed.berkeley.edu!newsswitch.lcs.mit.edu!news.ultranet.com!not-for-mail From: "Larry S. Samberg" Newsgroups: alt.sys.pdp10 Subject: Re: need the date of Day 4096 Date: Sun, 11 Apr 1999 15:33:38 -0400 Organization: Sonoma Systems Lines: 45 Sender: larry@bsg-ma1-248.ix.netcom.com Message-ID: <7eqtej$p3f$1@antiochus.ultra.net> References: <37082c39.88427826@netnews.worldnet.att.net> <7eq12e$qkn$2@ligarius.ultra.net> <7eq9nv$lvs$2@hirame.wwa.com> <7eqfvd$vjc$1@antiochus.ultra.net> NNTP-Posting-Host: bsg-ma1-248.ix.netcom.com Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Complaints-To: abuse@ultra.net X-Ultra-Time: 11 Apr 1999 19:33:39 GMT X-Newsreader: Microsoft Outlook Express Macintosh Edition - 4.5 (0410) Xref: news3.best.com alt.sys.pdp10:4756 Wow, what a memory. You are right, Rick did write the project plan. A name out of the past. But I think John was wrong. The 18+18 format was good for several hundred years (about 700) from 1858. So it would have done just fine for Y2K (except for DECtape). Also most of the routines that I remember dealt with the with century leapyear (or lack thereof) correctly. ---------------------------------------------------- Larry Samberg lsamberg@ieee.org Fax: 508-861-0261 larry@samberg.ultranet.com ICQ: 23815949 ---------- In article <7eqfvd$vjc$1@antiochus.ultra.net>, jmfbahciv@aol.com wrote: > In article <7eq9nv$lvs$2@hirame.wwa.com>, > jeverett@wwa.DEFEAT.UCE.BOTS.com (John Everett) wrote: >>In article <37082c39.88427826@netnews.worldnet.att.net>, >>> david.razler@worldnet.att.net (David M. Razler) wrote: >>> >>>Exactly what day was it when the 12-bit date memory field >>>expired requiring the emergency fix? >> >>January 5, 1975. Note that the original 12 bit date field >>has now overflowed three times; again in January, 1986, >>and in January, 1997. I forget the exact dates however. > > I also should have said that Rick Corbin wrote the project > plan (I think) and the spec. Now that's a name out of the > blue. :-) > >> >>I don't believe TOPS-10 will survive Y2K. >> > I don't know why. Somebody told me that they found > one or two Y2K bugs but never gave me the specifics. > I've actually spent some mind time trying to remember. > > /BAH > > Subtract a hundred and four for e-mail. Article 4758 of alt.sys.pdp10: Newsgroups: alt.sys.pdp10 Path: news3.best.com!news2.best.com!newsfeed.berkeley.edu!newsfeed.enteract.com!ix.netcom.com!netcom!alderson From: alderson@netcom.netcom.com (Richard M. Alderson III) Subject: Re: need the date of Day 4096 In-Reply-To: jmfbahciv@aol.com's message of Sun, 11 Apr 99 14:01:09 GMT Message-ID: Sender: alderson@netcom.netcom.com Reply-To: alderson@netcom.com Organization: NETCOM On-line services References: <37082c39.88427826@netnews.worldnet.att.net> <7eq12e$qkn$2@ligarius.ultra.net> <7eq9nv$lvs$2@hirame.wwa.com> <7eqfvd$vjc$1@antiochus.ultra.net> Date: Mon, 12 Apr 1999 17:58:45 GMT Lines: 20 Xref: news3.best.com alt.sys.pdp10:4758 In article <7eqfvd$vjc$1@antiochus.ultra.net> jmfbahciv@aol.com writes: >In article <7eq9nv$lvs$2@hirame.wwa.com>, > jeverett@wwa.DEFEAT.UCE.BOTS.com (John Everett) wrote: >>I don't believe TOPS-10 will survive Y2K. >I don't know why. Somebody told me that they found one or two Y2K bugs but >never gave me the specifics. I've actually spent some mind time trying to >remember. That was probably me, Barb. The monitor itself is fine; there were several CUSPs that had a little problem, but they were easily enough fixed. Since Tops-10 shipped with sources, anyone should be able to fix those with a judicious setting of the system clock. (I didn't do the investigation, so I don't know which CUSPs in particular.) -- Rich Alderson Last LOTS Tops-20 Systems Programmer, 1984-1991 Current maintainer, MIT TECO EMACS (v. 170) last name @ XKL dot COM Chief systems administrator, XKL LLC, 1998-now Article 4759 of alt.sys.pdp10: Path: news3.best.com!news2.best.com!newsfeed.berkeley.edu!newsswitch.lcs.mit.edu!news.ultranet.com!d5 From: jmfbahciv@aol.com Newsgroups: alt.sys.pdp10 Subject: Re: need the date of Day 4096 Date: Mon, 12 Apr 99 22:09:08 GMT Organization: UltraNet Communications, Inc. Lines: 29 Message-ID: <7eu0us$rum$1@antiochus.ultra.net> References: <37082c39.88427826@netnews.worldnet.att.net> <7eq12e$qkn$2@ligarius.ultra.net> <7eq9nv$lvs$2@hirame.wwa.com> <7eqfvd$vjc$1@antiochus.ultra.net> NNTP-Posting-Host: d5.dial-22.mbo.ma.ultra.net X-Complaints-To: abuse@ultra.net X-Ultra-Time: 12 Apr 1999 23:51:56 GMT X-Newsreader: News Xpress Version 1.0 Beta #4 Xref: news3.best.com alt.sys.pdp10:4759 In article , alderson@netcom.netcom.com (Richard M. Alderson III) wrote: >In article <7eqfvd$vjc$1@antiochus.ultra.net> jmfbahciv@aol.com writes: > >>In article <7eq9nv$lvs$2@hirame.wwa.com>, >> jeverett@wwa.DEFEAT.UCE.BOTS.com (John Everett) wrote: > >>>I don't believe TOPS-10 will survive Y2K. > >>I don't know why. Somebody told me that they found one or >>two Y2K bugs but never gave me the specifics. I've actually >>spent some mind time trying to >>remember. > >That was probably me, Barb. The monitor itself is fine; >there were several CUSPs that had a little problem, but >they were easily enough fixed. Since >Tops-10 shipped with sources, anyone should be able to fix those with a >judicious setting of the system clock. (I didn't do the investigation, so >I don't know which CUSPs in particular.) All right, now I'm really curious. $.02 says FILCOM had a problem. What are the other crufties? CREF; TECO wouldn't dare. And I bet the person who did the investigation didn't even touch the Customer Supported Tape :-). /BAH Subtract a hundred and four for e-mail. Article 4760 of alt.sys.pdp10: Path: news3.best.com!news2.best.com!news.maxwell.syr.edu!wn4feed!worldnet.att.net!wnmaster1!not-for-mail From: david.razler@worldnet.att.net (David M. Razler) Newsgroups: alt.sys.pdp10 Subject: Re: need the date of Day 4096 Date: Tue, 13 Apr 1999 01:24:04 GMT Organization: AT&T WorldNet Services Lines: 14 Message-ID: <37129745.99244595@netnews.worldnet.att.net> References: <37082c39.88427826@netnews.worldnet.att.net> <7eq12e$qkn$2@ligarius.ultra.net> <7eq9nv$lvs$2@hirame.wwa.com> <7eqfvd$vjc$1@antiochus.ultra.net> <7eu0us$rum$1@antiochus.ultra.net> Reply-To: david.razler@worldnet.att.net NNTP-Posting-Host: 12.68.21.220 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Trace: bgtnsc03.worldnet.att.net 923966677 6417 12.68.21.220 (13 Apr 1999 01:24:37 GMT) X-Complaints-To: abuse@worldnet.att.net NNTP-Posting-Date: 13 Apr 1999 01:24:37 GMT X-Newsreader: Forte Agent 1.5/32.452 Xref: news3.best.com alt.sys.pdp10:4760 j Getting back to my original question and curiosity..... I seem to remember that on 1/5/75 the LIRICS KA-10 and assorted other KA-10s around the nation crashed because of the date overflow (as in getting the news from LIRICS de-facto SYSOP Bruce Maier a day later) Since Bruce seems to have fallen off the face of the earth along with a lot of other people connected with the Damm Machine (after the name of the official SYSOP) I have no idea whether I'm dropping bits or some PDP-10 SYSOPS did not implement the patches properly or never got word to... Opinions, history, comments welcome dmr David M. Razler david.razler@worldnet.att.net Article 4744 of alt.sys.pdp10: Path: news3.best.com!nntp1.ba.best.com!not-for-mail From: inwap@best.com (Joe Smith) Newsgroups: alt.sys.pdp10 Subject: Re: need the date of Day 4096 Date: 5 Apr 1999 19:36:02 -0700 Organization: Chez Inwap Message-ID: <7ebrui$g49$1@shell3.ba.best.com> References: <37082c39.88427826@netnews.worldnet.att.net> Lines: 38 NNTP-Posting-Host: shell3.ba.best.com X-Trace: nntp1.ba.best.com 923366169 204 inwap@206.184.139.134 Xref: news3.best.com alt.sys.pdp10:4744 In article <37082c39.88427826@netnews.worldnet.att.net>, David M. Razler wrote: > >Exactly what day was it when the 12-bit date memory field expired requiring >the emergency fix? Method 1: 4096 divided by 31 = 132 with a remainder of 4. (item "A) 132 divided by 12 = 11 with a remainder of 0. (items "B" and "C") C: year = 11 + 1964 = 1975 B: month = 0 + 1 = January A: day = 4 + 1 = 5th Method 2: 4096 divided by (12*31) = 11 with a remainder of 4, therefore 11th year. 4 divided by 31 = 0 with a remainder of 4, therefore 1st month, 5th day. The date format was designed to be easy to determine on machine that had the integer divide instruction implemented in hardware. The hardware that implemented LDB and DPB (load and deposit byte instructions) was (theoretically) optional. TOPS-20 uses a date format that allows elapsed time to be calculated by simply subtracting two date numbers. The same cannot be said of the TOPS-10 12-bit or 15-bit date fields. Later versions of TOPS-10 used the 18+18 bit format internally, where the left halfword was incremented once a day, and the right half was a fraction of a day that was calculated once a second (but incremented by approximately 3 counts per second). -Joe -- INWAP.COM is Joe Smith, Sally Smith and our cat Murdock. (The O'Hallorans and their cats moved to http://www.tyedye.org/ Nov-98.) See http://www.inwap.com/ for PDP-10, "ReBoot", "Shadow Raiders"/"War Planets"