test-drb

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101090 discussions

Vector and ST506 (was ST506 and-or ST412 hard drives

by lynchaj＠yahoo.com

> Date: Mon, 31 Dec 2007 18:07:38 -0500 > From: "Andrew Lynch" <lynchaj at yahoo.com <http://www.classiccmp.org/mailman/listinfo/cctalk> > > The different signal is called a "constant index" signal. Apparently, it > is similar to an /INDEX signal from a floppy drive interface but the > signal tells the HD controller everytime sector 0 passes around. The HD > controller requires it for setting up the PLL. > > Here is an excerpt on the subject from the VG engineer: Well, the ST506 knows nothing from sectors--it's about as "bare" and interface as they come. I wonder if by "constant index" it's meant that there's always an INDEX/ signal present; not just when the drive is selected. At least that would make sense from this: > All hard drives working with a Vector FD/HD must have constant > index. There is a phase locked loop that is controlled by U20 which > is CMOS 4040 chip and unless you have constant index the PLL never... Maybe? What happens if the drive is jumpereed so as to be permanently selected? Cheers, Chuck -----REPLY----- Hi Chuck, Yes you are correct. I spoke with the VG engineer to get more details on "constant index" and you described it exactly. Apparently there is a cut and jumper modification which can be made to the ST506 circuit board to bring the /INDEX signal to the interface constantly even when the drive is not selected. Once I get a ST506 drive I will find and make the modification. Assuming I can get the ST506 to work, I will try making modifications to ST225's or other more common hard drives. I'd like to get the standard case working to establish if my VEDMCS is working properly before adding in other variables of different drives etc. Thanks! Andrew Lynch

18 years, 3 months

Vector and ST506 (was ST506 and-or ST412 hard drives

by cclist＠sydex.com

> Date: Tue, 1 Jan 2008 09:24:54 -0500 > From: "Andrew Lynch" <lynchaj at yahoo.com> > Yes you are correct. I spoke with the VG engineer to get more details on > "constant index" and you described it exactly. > > Apparently there is a cut and jumper modification which can be made to the > ST506 circuit board to bring the /INDEX signal to the interface constantly > even when the drive is not selected. I grabbed my ST506 off the shelf--it looks to be a very simple change. The control outputs are driven by 7438s and the cut and jumper on IC 6D looks to be easy to do. If you were loathe to modify the PCB on the 506, the index signal is also available on TP4 FWIW, there's a schematic of the ST506 on Bitsavers also. Cheers, Chuck

18 years, 3 months

New Item for Collection

by Paul.Bartlett＠axonglobal.com

Do you have any interest in adding an HP 9000 Series 400t Workstation (HP/UX), complete with VRX Graphics and 19" 98754A monitor, to your collection? Regards, Paul Bartlett. London Save a tree... Please don't print this email unless you really need to. The content of this email is confidential and for the addressee only. If you are not the addressee of this email (or responsible for the delivery of this message to such person) you may not copy, forward, disclose or otherwise use it or any part of it in any form whatsoever. If you have received this email in error please email the sender by replying to this message and delete this message thereafter. Opinions, conclusions and other information in this message that do not relate to the official business of our Company shall be understood as neither given nor endorsed by it. Axon Solutions Limited Registered Office: Axon Centre, Church Road, Egham, Surrey, TW20 9QB, UK Registered in England & Wales under Company No. 2976395 Axon Solutions Limited is a limited company. Axon Group plc Registered Office: Axon Centre, Church Road, Egham, Surrey, TW20 9QB, UK Registered in England & Wales under Company No. 3419641

18 years, 3 months

HP Tape drive for Christmas (Jason T)

by js＠cimmeri.com

I use a Cipher M995S 9 track on a 486PC w/ DOS and Adaptec controller ...using either Central Point Backup v.9, or John Wilson's (dBit) Scsi Tape utility. ~ J

18 years, 3 months

ST506 and/or ST412 hard disk drives

by ard＠p850ug1.demon.co.uk

> I have the same question. The ST506 and ST412 were different > in the WrPrecomp signal being changed to a head select for > the ST412. I think he is looking at documents that state that he > needs a ST506/412 interface. This would be compatable with > just about any MFM drive made after the ST412. > > There was a signal on some drives that came on the data cable. > I think it may have been a write protect but I don't recall > exactly what it was. The ST506 may have used this signal. > I'm not sure if this is what he is talking about. Some, if not most, ST506/ST412 interface drives output a signal on the data cable when that drive is selected. The idea was you could plug the data cables into the controller in any order, and the controller could determine which data connector to use, which receivers to enable, etc. It's a pity few controllers made use of that! I'm not aware of any write-protect signal on the data connector of any such drive. -tony

18 years, 3 months

Wanted: Vax "sol" or "saul"

by dgahling＠hotmail.com

I'm not sure how the name was spelled, so I put both here. basically it was a vax in a notebook type arrangement. I once located one in London ontario, but I've lost contact with the person who had it :( so if anyone has one, I've been looking for a very long time, and it'd be appreciated. thanks! Dan. _________________________________________________________________ Read what Santa`s been up to! For all the latest, visit asksantaclaus.spaces.live.com! http://asksantaclaus.spaces.live.com/

18 years, 3 months

Modem to Modem without a line simulator?

by tsw-cc＠johana.com

>From a digest article I must comment on... > Is it possible to connect two modems (eg: Hayes 2400 to Hayes 2400) > using a 'dead' or isolated pair of copper wire and have them be able > to communicate? As said before, just get one modem in Originate mode, and the other in Answer mode and go from there. Most "modern" modems (that have some Part 68 certification) can do this quite easily as long as you have access to the command stream on each side. The more difficult is when you don't (usually on one side). Then you attempt to get the "answering" modem in answer mode sending its carrier before he "originating" modem asks for it, and will sense it when it wants to. The part that is touchy is making the timeout on the "answer" side long enough. Ob ClassicComp: I should really try this with my Bell 103A modem (I got one, don't ask!) to see if I can get it to "connect". It might need some DC voltage >from tip to ring (green wire to red wire) to trip some relay (it was before optical couplers!). What an experiment to do! If you want to make two "500" sets talk to each other, a nice 6 Volt battery works quite well placed in series with the two sets. It won't make them ring, but you CAN talk. Use a lantern battery (or 4 D cells) and unless you are making DTMF (touch-tone) on a polarity sensitive set (older 2500 sets) polarity makes little difference. -- Sorry, No signature at the moment. ____________________________________________________________________________________ Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs

18 years, 3 months

Emailing: ST506 and-or ST412 hard drives.htm

by lynchaj＠yahoo.com

> From: pete at dunnington.plus.com <http://www.classiccmp.org/mailman/listinfo/cctalk> ---snip--- >> >> There was a signal on some drives that came on the data cable. >> I think it may have been a write protect but I don't recall >> exactly what it was. The ST506 may have used this signal. >> I'm not sure if this is what he is talking about. > > There's a "drive selected" signal, but I think most drives have that. > It's there because the 34-way control cable is daisy-chained but the > 20-way data cable is radial, one per drive. Yes, that may have been it. If he is using just one drive, this shouldn't be an issue. > >> I'd suspect things like step rate and number of heads would >> be more important to him than anything else. > > The other important difference between the ST506 signals and the ST412 > was that the ST506 didn't support buffered seek; the timing of the step > signals had to be slow enough that the stepper motor could keep up. The > ST412 was the first drive that buffered the step signals, so they could > be sent rapidly, and virtually every hard drive after that did too. > This is important because many drives that had the auto step, were really slow using the fixed rate step. I had this problem getting a ST251 to run on my Olivetti M20. The original drive had a fast step rate of something like 6 ms. The ST251 wouldn't work faster than 10ms as I recall but the auto rate was much faster. I think we need to hear from Andrew to see just what it is he is talking about. From his original post, I still think he has something confused. Dwight _________________________________________________________________ The best games are on Xbox 360. Click here for a special offer on an Xbox 360 Console. http://www.xbox.com/en-US/hardware/wheretobuy/ ________________________________ -----REPLY----- Hi, Yes, I'll admit this can be a bit confusing and I am bit puzzled by it as well. I had not heard of anything like it either but I have to believe the VG engineer to know what he is talking about. However, I have heard from a former Vector Graphic engineer who is intimately familiar with the VEDMCS (aka, the integrated FD/HD controller) and he tells me that the ST506's used for the VEDMCS are different than the generic "off the shelf" ST506 hard drives. I believe the stock ST506 is modified or configured to provide the signal in some manner. The different signal is called a "constant index" signal. Apparently, it is similar to an /INDEX signal from a floppy drive interface but the signal tells the HD controller everytime sector 0 passes around. The HD controller requires it for setting up the PLL. Here is an excerpt on the subject from the VG engineer: " All hard drives working with a Vector FD/HD must have constant index. There is a phase locked loop that is controlled by U20 which is CMOS 4040 chip and unless you have constant index the PLL never has time to sync up and gives read errors. " I have seen the VEDMCS driver source code and it specifically lists the ST506 and the ST412 as its only two supported drives. I'd like to start witho one of those and see if I can get it work. Maybe I could convince it to accept a ST225 instead of a ST412 but so far I haven't had any luck. I keep getting "drive not ready" errors. I hope this helps explain this situation. Thanks! Andrew Lynch

18 years, 3 months

HP Tape drive for Christmas

by silent700＠gmail.com

So on the 24th I trucked up to Milwaukee (from Chicago) for a $100 SGI haul, the star of which was a working Crimson with three hard drives. Brought back the Crimson and some Indigo 2s (which will be for sale/trade/free as soon as I inventory them.) There was supposed to be an O2 as well, but it went missing. So for the pre-arranged price I asked to hunt around the shop for a replacement item, which turned out to be the back-breaking HP 88780B 9-Track Tape Drive! A fair trade-up, I'd say. So I've got it home and onto a table. This may be old-hat to some, but having never used a 9-track before I have to say the air-powered self-threading mechanism is the coolest thing I've seen all month. I loaded a blank tape for the self-test, which passes. Now to get it to write some real data, and eventually use it to rescue some old tapes I've had for years as well as the one I bought at VCF. I'm guessing that any modern *nix machine should recognize it and be able to read it. I planned on using a Sparc IPX or something similarly portable when I get one formatted and loaded. In the meantime, I have my laptop. Is there any chance of getting WinXP to use this beast? I have a SCSI PCMCIA card on the laptop which I've used to read old hard drives, but drivers will be the issue here. I know in most cases the backup software needs to be able to handle the drive as well as the OS - anyone tried to use Backup Exec or any of the other big commercial s/w with one of these? Thanks in advance... -- jht

18 years, 3 months

updates to the Alpha Micro Phun Machine

by spectre＠floodgap.com

A greatly updated history of Alpha Micro, including their use of alternative operating systems such as UNIMOS/Unix and Pick, and the invasion of the clone systems, is now up on the Alpha Micro Phun Machine. In addition, the models page is tremendously expanded with corrected chronology and more information on loadouts. This is all with the help of Bob Fowler, who graciously allowed me to raid his AMUS document archive and take images. He also put a lot of his software onto a QIC tape for me, but naturally my AM-626 streamer has decided to be recalcitrant, so this will wait for the next update until I can fix it. Also, I recently acquired an AM-1200, and there will be a model page for that as soon as I get it operational. http://ampm.floodgap.com/ -- ------------------------------------ personal: http://www.cameronkaiser.com/ -- Cameron Kaiser * Floodgap Systems * www.floodgap.com * ckaiser at floodgap.com -- The son becomes the father, the father becomes the son, the uncle has a beer.

18 years, 3 months

HP Tape drive for Christmas

by aek＠bitsavers.org

> Failing that, if you have bootable Linux CD, it should deal with the > drive just fine. Apparently, modern Linux distros have depreciated the 'mt' command. You have to install the 'mt-st' package to get it. Eric Smith's tapecopy program seems to work ok, other than the known quirks like an endless stream of -1 length blocks if the tape stalls.

18 years, 3 months

ST506 and/or ST412 hard disk drives

by ard＠p850ug1.demon.co.uk

> > From: pete at dunnington.plus.com > ---snip--- > >> > >> There was a signal on some drives that came on the data cable. > >> I think it may have been a write protect but I don't recall > >> exactly what it was. The ST506 may have used this signal. > >> I'm not sure if this is what he is talking about. > > > > There's a "drive selected" signal, but I think most drives have that. > > It's there because the 34-way control cable is daisy-chained but the > > 20-way data cable is radial, one per drive. > > Yes, that may have been it. If he is using just one drive, > this shouldn't be an issue. Actually it would be if the controller depends on it, even if you only have one drive. If that drive doesn't output the 'drive_selected_ signal, then the contorller might not enable any data receivers. > > > > >> I'd suspect things like step rate and number of heads would > >> be more important to him than anything else. > > > > The other important difference between the ST506 signals and the ST412 > > was that the ST506 didn't support buffered seek; the timing of the step > > signals had to be slow enough that the stepper motor could keep up. The > > ST412 was the first drive that buffered the step signals, so they could > > be sent rapidly, and virtually every hard drive after that did too. > > > > > This is important because many drives that had the auto step, were > really slow using the fixed rate step. I had this problem getting The really strange lone (not the same interface, of course, but similar in concept) is the SA4000 (14" Winchester). On that drive, you eitehr have to send pulses so slowly that the the head movement it completed for each one (that is, the head gets to the next track before you send the next pulse) or fast enough that you've sent all of them before the heads start to move. An intermediate rate will end up with the darn thing mis-stepping. This is docuemtned in the manaul and the reason for it (one up/down counter with a common clock input to record the head offset) is clear from the schematics. -tony

18 years, 3 months

ST506 and/or ST412 hard disk drives

by ard＠p850ug1.demon.co.uk

> First, I'm not sure what you mean by ST506 and ST412. I thought > these were different in that one had a signal used for write precompensation > while the other used the same line for a head select. Weren't both of those 4 head drives? THe ST412 is part of a family (ST406, ST412, ST419) which were 2, 4, 6 head drives from what I can see. I thought the ST506 was 4 heads but fewer cylinders. I also thought the main difference between the ST506 and ST412 interface was that the latter alloewed buffered seeks, the former didn't I am still curious as to what the 'speacial' signal is. -tony

18 years, 3 months

Modem to Modem without a line simulator?

by ard＠p850ug1.demon.co.uk

> The current is used for the carbon mike and to tell the > phone system that the phone is off the hook. Line connected > modems don't have any use for the current and only have > a load resistor there to keep the line connected. Something I forgot about earlier : I think the GPO Modem 13A (A plinth mounted under a normal dial-type phone) could be strapped to draw its power from the line. I don't know the full deatails, I do have one of these modems (300 baud CCITT oriignate only), but I have no diagrams other than the connection lable stuck inside. But there's certainly a transformer-isolated PSU circuit on the board, and one setting of the straps seems to connect the input of this to the line -tony

18 years, 3 months

Testing

by ard＠p850ug1.demon.co.uk

Just a mail test -tony

18 years, 3 months

Emailing: Source for EEPROMs.htm

by lynchaj＠yahoo.com

All: I?m in the process of getting a floppy system running on my IMSAI (I should have CP/M running on it tomorrow; a separate book report to follow since I polled this group a few times for info on the topic) and I?ve been burning/erasing a lot of EPROMs to get it done. I have an EPROM emulator somewhere but I can?t find it. Anyway, my programmer can also handle 28C16 EEPROMs. I located some at Jameco ($4@) and at JDR ($4.50@) but I was looking for a cheaper source if possible. Googling produces tons of sites with either data sheets or industrial recovery companies that want to sell 100 of them at a shot. At most I?d probably buy a tube (15 or 20) of them. Any pointers would be appreciated. Thanks again, and Happy New Year to all. Rich -- Rich Cini Collector of Classic Computers Build Master and lead engineer, Altair32 Emulator http://www.altair32.com http://highgate.comm.sfu.ca/~rcini/classiccmp ________________________________ -----REPLY----- Try Unicorn Electronics. I have bought some 28C16's from them before and they are OK. http://unicornelectronics.com http://unicornelectronics.com/IC/EEPROM.html Thanks! Andrew Lynch

18 years, 3 months

Source for EEPROMs

by rcini＠optonline.net

18 years, 3 months

Mail formatting

by cclist＠sydex.com

> Date: Mon, 31 Dec 2007 09:41:58 -0600 > From: John Foust <jfoust at threedee.com> > >I beleive the original intention was that 0x7F would be _ignored_. The > >point being you could overpunch any characeter on paper tape to turn it > >into 0x7F (all holes), and thus you could effectively delete that > >character from the tape > > Wasn't it used to indicate that the previous character could > be ignored? No--the use is "Rubout"--erase an erroneous character by overpunching all holes. Deleting characters from punched paper tape is otherwise very difficult without a pair of scissors. Back on topic, one thing that seems to be confused here is the *function* of the newline/carriage return/whatever. One function is as a format effector (i.e. print control; the other is as a record delimiter. Confusing the two roles leads to problems. For example, if CR is used as a record delimiter, then there's no easy way to indicate that the next line on a printing device should overprint the next line on the current one. By the same token, using linefeed as a record delimiter forces the next record to insert spaces in the next record to simulate a vertical motion of the printing position without a corresponding return to the beginning of line. If one is to have character-delimited records, better to use a character whose function is to delimit records rather than control printing behavior. I believe that the Beehive SuperBee sent 1/15 as an end-of-line character rather than CR, at least in screen editing mode. By the same token, 0/8 BS does not imply that a character is to be erased when the printing position is moved back; the implication is that the next character will overprint the previous one. CRT terminals and their simple-minded mode of operation pretty much forced this behavior and it's curious that with our GUI displays that we still mimic the faulty behavior. I recall that this was an issue in the original Videotex spec--IIRC, certain characters could be combined using BS. Cheers, Chuck

18 years, 3 months

Anyone have a "Chain Train" printer from Data Printer corp? I have ribbons...

by ian_primus＠yahoo.com

Doing some cleaning here at work, and have located several boxes of new, sealed ribbons from old Chain Train printers made by Data Printer Corp. These are some seriously unusual ribbons - about 14" wide rolls. We also have some parts for these machines. Anyone have one of these beasts? -Ian

18 years, 3 months

Have the microvax user diag tapes been imaged?

by aek＠bitsavers.org

I have a couple that are sticky/shedding. Before I spend a lot of time trying to recover them, has someone imaged them already? They are from 87-89.

18 years, 3 months

ST506 and/or ST412 hard drives

by ard＠p850ug1.demon.co.uk

> > Hi, > > I am restoring a Vector Graphic computer and would like to add a hard > disk drive. The controller only supports two kinds of hard disk > drives, the ST506 and ST412. The HD controller is hard coded to > support these DRIVES not just a compatible interface and relies on a > special signal present only in these actual drives. What signal is that? I've looked at the schematics for thsoe (although not recently) and I can't remember any extra signals on the connector. Can this signal, if it exiasts, not be 'faked' on some other drive? -tony

18 years, 3 months

Mail formatting

by ard＠p850ug1.demon.co.uk

> > One of the recurring issues of ASCII is: > > "What is the ASCII code for newline?" > > What I've heard---there is no one character that returns the carriage to > the start of the line (CR) and advances down one line (LF). MS-DOS seems to That, indeed, is how the Teletype 33 behaves. And 5-level teleprinters normally had separate CR and LF codes that acted in that way. > think both are required, whereas Unix went with one (LF) and add both if > required in the driver code. The older versions of Mac OS (prior to being > Unix under the hood) used CR. And while I wrote code to handle CR, LF, TRS-80s used CR only IIRC. In fact they _sent_ CR only to the printer as standard, which could be a a problem if you had a non-Radio-Shack printer, or if you wanted to use an Radio Shack printer on some other machine. There were 'filters' for some TRS-80 OSes to add the LF. Most older printers had an internal DIP switch to set an 'Autofeed' -- that is to do a linefeed (as well as returning the carriage). There was also a pin on the Centronics connector to enable/disable this feature. IIRC the BBC micro has a operating system call to set the 'printer ignore character'. At power-on this was set to 0x0A (LF). I think the OS would try to send CR LF, the printer driver routine would then delete the LF so that only the CR got through (requring a printer that did an autofeed), then you could change the 'ignore' character to something else if the printer neeeded both CR and LF. The HP9866 is a thermal line printer (prinhead the full width of the paper, but only one dot high). From what I can deduce from the scehamtics, it ignroes CRs totally, when it gets an LF it springs into life and prints the contents of its buffer. > CRLF, LFCR, I never did see LFCR in the wild. I think I did, once. Really confuesed a bit of software I was using too... > > Another recurring issue for ASCII: what is baskspace supposed to do? > I'm used to systems that use $08 [1] to move the cursor left one column and > overwrite the character there with a space. But Linux (maybe because Linus > was secretly a DEChead?) decided that $7F would move the cursor left one > column and overwrite the character there with a space, but X Windows (which > I use on Linux) seems to want to use $08 for that. I beleive the original intention was that 0x7F would be _ignored_. The point being you could overpunch any characeter on paper tape to turn it into 0x7F (all holes), and thus you could effectively delete that character from the tape -tony

18 years, 3 months

Wanted: PDP-11 MUMPS Software & Manuals

by James＠jdfogg.com

> Hi, > > I'm looking for Software & Manuals for any of the MUMPS implementations > for the PDP-11, > e.g. MUMPS-11, DSM-11 or M/11+. > > Can anybody help? Intersystems in Cambridge Massachusetts, USA was the last company to own/publish this software. They may still support it. My older brother used to maintain their Data General and UNIX versions.

18 years, 3 months

Modem to modem without a line simulator

by ard＠p850ug1.demon.co.uk

> > > This question is bugging me from another forum. > > Is it possible to connect two modems (eg: Hayes 2400 to Hayes 2400) > using a 'dead' or isolated pair of copper wire and have them be able to > communicate? > > I always thought that this can not work because the line that the modems > are connected to has to have some current. The phone system works > because an action on one end of the phone (talking into the carbon > microphone) causes a reaction on the other end. Without some sort of > current on the line, how can this work? Hence the need for 'line > simulator' circuits Most direct-connect modems do not require any power from the telephone line -- in fact the modem circuitry is coupled to the line through an isolating transformer, which is iteself capacitor-coupled to the line. So the DC conditions on the line have no effect on the modem circuit Of course such modems do 'loop the line' (provide a DC path between the 2 line wires) when off-hook. But that's to tell the telephone exchange that the modem is indeed off-hook, not for any particular requirement of the modem So if you can get onee modem to ignore the lack of dial tone/rigning tone, andthe other one to answer without seeing a rining voltage on teh line, then just connecting them together should work. I think there have been a few -- a very few -- modems that do requeire a DC voltage on the line for correct operation. Foe those, you can often fake it by connecting a suitable DC supply in series with a suitable limiting resistor between the line wires. > > Some people are claiming that it works without the line simulator. I'd > like to understand why. > > (I could get out the multimeter if things get really desperate, but > maybe somebody can tell me that the line current thing only applies to > acoustically connected modems, not direct connect. Or the direct > connect modems put enough juice on the line to make it work. Or > something else that might make sense.) Telephones, of course, do draw power from the line, which means accoustically-coupled modems need line power for the asscoicated telephone. -tony

18 years, 3 months

Compaq "Enhanced II Keyboard" - what's with these?

by listmailgoeshere＠gmail.com

Hi list, I have two "Compaq Enhanced II Keyboard"s here (they look old enough to be on-topic) - PS/2 connector, but they don't work on any PC I've tried them with. Are these specific to one machine? If so, is there any interest before I dumpster them? Thanks, Ed.

18 years, 3 months

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