test-drb December 2006

test-drb@ccmp.vtda.org

225 participants
420 discussions

by Billy.Pettit＠wdc.com

Amazon has several used ones - try http://www.amazon.com/exec/obidos/ISBN=067220715X/donlancastersgurA/ And Don's web page is always fun to visit : http://www.tinaja.com/ Billy

18 years

Bell 103 Datasets (was: HP 2000F')

by Billy.Pettit＠wdc.com

Richard asked: Speak of Bell modems, does anyone have a timeline or reference for modem equipment before the phone system was broken up and anyone was allowed to make them? Wikipedia has an entry for the Bell 103 300bps modem, which they say was released in 1962. There is also an entry for the Bell 202 1200bps modem with no date reference. Does anyone else have more complete information about modems before the diversity of manufacturers entered the scene? -- Can't help you on the official time line. But I can put dates to my first contacts with them. I helped build a system for the IRS that used the Bell 101. This was in the fall of 1963. We had both Bell 301's and 103's in the lab. And retrofitted the 101's to 301's early in 1964. All of these units were transistor based. The first remote terminal systems we shipped to DARPA used racks of 101's driving teletypes. This was also late 1963. The first non-Bell data set I worked on was in 1967. It was a mature design, IC based, high volume, so probably started in 1966. Billy

18 years

RTL - was Build your own Apollo Guidance Computer

by Billy.Pettit＠wdc.com

Chuck Guzis wrote: On 20 Dec 2006 at 11:21, James B. DiGriz wrote: > Now that is something I didn't know and find very much worth looking > into. Any quick pointers to info on RTL operating in this mode? I'll dig through my old literature. I recall that Motorola offered an "Experimenter's Kit" of about 6 of their TO-99 packaged milliwatt RTL circuits with some non-digital application notes. Anyone still have the little booklet that came with this kit? Cheers, Chuck ---------------------------------------------------- I know that RCA also had a nice set of Application Notes for introducing RTL. I'm not certain I still have them - came out in 1962. Some of the early RCA data books still had them inside. Maybe one of our data book collectors has copies. If so, I'll be glad to scan them. Al, does your data book collection have an RTL book? And I have seen an RTL CookBook-like manual with a bunch of circuits in it. Would have been in 1969-70. I believe I bought it England. Had a green cover, paper boards. I want to say Plessey published it, but the synapses aren't firing on this one. Maybe one of our English members remembers it? Any one have a copy? Billy

18 years

A new addition

by quapla＠xs4all.nl

Picked something interesting up a few days ago, a graphical system which used to be part of a spectrum analyzer. It's a PDP-11/23+ with a graphics option, a monitor, joystick, an interface box for the keyboard, an Ampex diskdrive which uses packs and has a fixed disk inside and a Printronix lineprinter with 4 spare ribbons ((these are big, abouth an inch or so wide) It comes with XXDP+ (no idea which version yet), a library disk, a disk with RSX11M+ V3.0D and a stack of 30 extra data disks. Fortunately, the system docu is there, both for the machine, drive and printer. First thing to do is to hook up an RL02 to copy the sw over. The drive is an SMD type disk, it is controlled by an Emulex SC02 interface. Im not going to use this drive a lot, so if there are people who wants to take some of these data packs, you're welcome to get some. Ed

18 years

What to do with a VAX KA655 board that is prone to CDAL parity error?

by vax9000＠gmail.com

It looks clean and great, but it reports CDAL parity error (machine check 10) randomly if the panel head is installed in place, when it is processing bulk of data. If the panal head is hanging there loosely, the chance of getting a CDAL parity error is much much rarer. What could cause this problem? A defective cache memory chip? supportive TTL chip? capacitors? Or is it better for me to unsolder the CPU and sell it to collectors? Any idea? vax, 9000

18 years

HP 2000F'

by rickb＠bensene.com

>The consensus was that we did "HEL" to login and that the accounts >were <alpha><digit><digit><digit>, in particular X999 was the games >account. (That rang a memory chord with me when it was mentioned.) >It was also remembered that A000 was the "root" account on the >machine. The login was of the form HEL-XYYY,<password> for the earlier systems, and later, HEL-XYYY,<password>,<terminal identifier>. The password was usually a combination of non-printing control characters to avoid the password showing up on the teletype printout. X was a letter from A through Z. YYY was 000 through 999. If the last two digits of YYY were 00, then the account was a "group" account, which was available to all members of that group as a library account, for shared files/programs. A000 was indeed the "root" account, which did have access to a few extra commands. Z999 was also an interesting account --- it was the "system overhead" account. All available "free" disk space was available to this account. In 2000C and C' systems, there was a "beature" (a cross between a bug and a feature) where if the "NAM" (name a program) command was issued with an argument of ",", e.g., "NAM-,", the user would get "dropped" into the Z999 account with no password request. It's unclear if this was a "back door" for HP service personnel, or if it was a bug, but it was explicitly noted in the user's manual for the system that "," was an invalid argument to the NAM command. "NAM-," would simply be acknowledged by the TSB system sending a linefeed, indicating that the command had been processed. At this point, it was possible for a user to "crash" the system by asking it to create a file that was so large that it consumed the remainder of free disk space. The timeshare system could also be "locked up" for varying periods of time by creating large files. In TSB, data files had to be pre-allocated to a given size, and all of the blocks were "claimed" as part of the creation process. For example, doing a "CRE-FILE,10000" would create a 10,000 block file. Normal user accounts were limited to perhaps 100 to 200 blocks of storage. Creating a 10,000 block file took the system quite a long time, and during that time, all timesharing operations would cease while the system was locked in "system state", creating the file. This was discovered by a friend and myself in high school. It was quite interesting the first time we tried "NAM-,", simply because the manual said it was invalid, and were quite surprised when the system just accepted the command, but didn't appear to do anything. We then typed "CAT" (shows disk catalog), and it showed an empty directory, with a large number of available blocks. We tried "CRE-FILE,1000" at first, and when we hit RETURN, we noted that there was a period of time where the other three teletypes which were active in our high school computer center stopped typing, or even echoing input, until our command completed, then everything resumed where it left off. We deleted FILE, and then tried CRE-FILE,10000, and the other terminals stopped...dead in their tracks, for a few minutes (most people thought the system had crashed, and turned off their teletypes) while the system was creating this large file. We then did a PUR-FILE (PURge - deleting the file), which again locked things up (for a period of less time) while the system was deleting the file. We then did a "CRE-FILE,1000000", which was in excess of the number of blocks that the "CAT" (CATalog) command showed, and the system "went away", and the computer math teacher soon got a call from the data center saying that the system had crashed for unknown reasons, and that it would be some time before it would come back. We had quite a bit of fun writing little programs which would wait for a specific time (during other people's classes), and then "crash" the system at that time. Eventually, we got caught. We didn't get into too much trouble. How they tracked us down, I'm not sure, but I believe that through the crash dumps that the system generated when it crashed, HP engineers were able to figure out which async mux line was causing the problem, and then tracked it back to our school. A patch was put in place that fixed the problem, resulting in an "ILLEGAL FORMAT" error if NAM-, was entered. This fix was incorporated into all later releases of HP 2000 TSB, including HP 2000F, HP 2000F', and HP 2000/Access. I sure loved these systems. They were wonderful systems to learning the basics of computing through. They weren't as fully featured or flexible as competitor Digital Equipment's RSTS/E timeshare systems (I have other fun stories to tell about finding bugs in RSTS/E), but they HP system were really a lot of fun, especially 2000/Access, which added a lot of neat functions. I'm really happy that Jay has managed to find the various special bits (microcode and mux hardware) that makes it possible to have an operational HP Timeshared BASIC system running as "the real thing". Rick Bensene The Old Calculator Web Museum http://oldcalculatormuseum.com

18 years

Help With an Erastz-11 DLL

by jhfinedp3k＠compsys.to

Can anyone help me with a simple link to an assembler / linker for a Pentium III / Pentium 4? I am attempting to use the EMEM.DLL (Emulated PDP-11 Memory) under Ersatz-11, but I am basically a dummy when it comes to using X86 code, especially finding a pair of suitable assembler / linker programs. I downloaded the Watfor programs, wasm.exe and wlink.exe, but I am not able to assemble the original file, EMEM.ASM at this point. In case anyone is interested, the EMEM.DLL under E11 provides access to PC RAM via emulated PDP-11 hardware registers. The current version which I have been using allows up to 8 MBytes, but I want to increase that to about 600 MBytes so that I can write a faster sieve program for Prime Numbers which looks like it runs in a PDP-11. If I can get the test version to run fast enough on a Pentium III, I will try it on a Pentium 4 with 4 GBytes of memory and see if it is possible to sieve the primes up to 10**18 (essentially a 64 bit sieve program) in a reasonable time (i.e. less than 1 year!). Sincerely yours, Jerome Fine -- If you attempted to send a reply and the original e-mail address has been discontinued due a high volume of junk e-mail, then the semi-permanent e-mail address can be obtained by replacing the four characters preceding the 'at' with the four digits of the current year.

18 years

SPAM (on list) was:Re: classiccmp list (sort of) help requested

by sdc695＠yahoo.com

The growing problem with SPAM, etc.. It was noted in one of the trade publications I looked at that a very effective check on SPAM was to confirm that the stream opened up to you (on your port 25) actually did a "conversation" with the remote player. It seems that the 'bots just open up port 25 and send (spew), and ignore the responses. Kinda like 'typeahead'. If you can sense this, it quashes some stuff (so I've been told). Another tact might be to see if the sender HAS a port 25 on their machine. I suspect that the 'bot machines don't. Just a couple of ideas. Unfortunately fixes like these require a deep diving into the SMTP mailer at the code level. ob. on topic.. Sendmail is over 10 years old (maybe that is the problem!) -- Tom Watson tsw at johana.com ____________________________________________________________________________________ Have a burning question? Go to www.Answers.yahoo.com and get answers from real people who know.

18 years

Searching for some PDP-11/23-PLUS items

by spedraja＠ono.com

Hi. I could finally get some time to put in working state my PDP-11/23-PLUS. Once I could check the correct startup of the system, I should like to obtain these items that detail below: * Original rack for this system, with its 874 power controller, backpanels and rack inner metal rails. * Cable kit for one RLV12 (RL02 controller board), at least for two RL's * TSV05 (Pertec) cable kit. I have the tape unit and the board but no cables * -YA terminator for one BA11-S expansion box. I have the main BA11-S plus another one to extend the system, plus both connection boards (plus cables) for the boxes, but the PDP-11/23-PLUS manuals speak about another terminator board. I only remember now the final part number letters (-YA). Other items are welcome, but I suppose it would be more difficult their transport. I am mostly interested in one or a couple of working RL02. If someone can get rid of some of this, or even sell it for a reasonable price, contact me off list. I live in Europe, by the way. All indications and suggestions about these matters are welcome too. Greetings Sergio

18 years

Advice for tape drive repair / maintenance

by jtp＠chinalake.com

A number of years ago I had some luck making rollers using two methods: (1) Use a double punch to punch out thin doughnuts of rubber--too thick deforms on punch. Stack them on the shaft tacking them with a very small amount of silicon or urethane glue. Mount in chuck of drill press and turn slowly against stones of different coarsenesses to smooth the surface. You may need to fiddle with the speed to get a good finish. This method usually requires that you can somehow cap the top and bottom of the roller, especially if the doughnut is wide. (2) Cast a new roller using urethane or silicon. Mount the shaft, or tube that represents the inner diameter, in a drill press. Using an n-way machining vise, center the outer tube with the inner shaft. Pour in goo, lower inner shaft into goo using the press handle and fine tune the positioning with the vise if needed. I turn the shaft a few times to get the goo the settle and air to vacate. Let harden, remove with plunger, heat or cold. Trim as needed. For outer casings, I've used pvc and copper tubes, but the smoothest results are with a machined and polished steel tube, open at the bottom to help push the roller out. For one roller that would not stick to the shaft, I milled several grooves in the shaft and repoured. This kept the rubber from turning. -jim

18 years

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test-drb December 2006