Announcement

Collapse

Forum Rules and Etiquette

Our mission ...

This forum is part of our mission to promote the preservation of vintage computers through education and outreach. (In real life we also run events and have a museum.) We encourage you to join us, participate, share your knowledge, and enjoy.

This forum has been around in this format for over 15 years. These rules and guidelines help us maintain a healthy and active community, and we moderate the forum to keep things on track. Please familiarize yourself with these rules and guidelines.


Rule 1: Remain civil and respectful

There are several hundred people who actively participate here. People come from all different backgrounds and will have different ways of seeing things. You will not agree with everything you read here. Back-and-forth discussions are fine but do not cross the line into rude or disrespectful behavior.

Conduct yourself as you would at any other place where people come together in person to discuss their hobby. If you wouldn't say something to somebody in person, then you probably should not be writing it here.

This should be obvious but, just in case: profanity, threats, slurs against any group (sexual, racial, gender, etc.) will not be tolerated.


Rule 2: Stay close to the original topic being discussed
  • If you are starting a new thread choose a reasonable sub-forum to start your thread. (If you choose incorrectly don't worry, we can fix that.)
  • If you are responding to a thread, stay on topic - the original poster was trying to achieve something. You can always start a new thread instead of potentially "hijacking" an existing thread.



Rule 3: Contribute something meaningful

To put things in engineering terms, we value a high signal to noise ratio. Coming here should not be a waste of time.
  • This is not a chat room. If you are taking less than 30 seconds to make a post then you are probably doing something wrong. A post should be on topic, clear, and contribute something meaningful to the discussion. If people read your posts and feel that their time as been wasted, they will stop reading your posts. Worse yet, they will stop visiting and we'll lose their experience and contributions.
  • Do not bump threads.
  • Do not "necro-post" unless you are following up to a specific person on a specific thread. And even then, that person may have moved on. Just start a new thread for your related topic.
  • Use the Private Message system for posts that are targeted at a specific person.


Rule 4: "PM Sent!" messages (or, how to use the Private Message system)

This forum has a private message feature that we want people to use for messages that are not of general interest to other members.

In short, if you are going to reply to a thread and that reply is targeted to a specific individual and not of interest to anybody else (either now or in the future) then send a private message instead.

Here are some obvious examples of when you should not reply to a thread and use the PM system instead:
  • "PM Sent!": Do not tell the rest of us that you sent a PM ... the forum software will tell the other person that they have a PM waiting.
  • "How much is shipping to ....": This is a very specific and directed question that is not of interest to anybody else.


Why do we have this policy? Sending a "PM Sent!" type message basically wastes everybody else's time by making them having to scroll past a post in a thread that looks to be updated, when the update is not meaningful. And the person you are sending the PM to will be notified by the forum software that they have a message waiting for them. Look up at the top near the right edge where it says 'Notifications' ... if you have a PM waiting, it will tell you there.

Rule 5: Copyright and other legal issues

We are here to discuss vintage computing, so discussing software, books, and other intellectual property that is on-topic is fine. We don't want people using these forums to discuss or enable copyright violations or other things that are against the law; whether you agree with the law or not is irrelevant. Do not use our resources for something that is legally or morally questionable.

Our discussions here generally fall under "fair use." Telling people how to pirate a software title is an example of something that is not allowable here.


Reporting problematic posts

If you see spam, a wildly off-topic post, or something abusive or illegal please report the thread by clicking on the "Report Post" icon. (It looks like an exclamation point in a triangle and it is available under every post.) This send a notification to all of the moderators, so somebody will see it and deal with it.

If you are unsure you may consider sending a private message to a moderator instead.


New user moderation

New users are directly moderated so that we can weed spammers out early. This means that for your first 10 posts you will have some delay before they are seen. We understand this can be disruptive to the flow of conversation and we try to keep up with our new user moderation duties to avoid undue inconvenience. Please do not make duplicate posts, extra posts to bump your post count, or ask the moderators to expedite this process; 10 moderated posts will go by quickly.

New users also have a smaller personal message inbox limit and are rate limited when sending PMs to other users.


Other suggestions
  • Use Google, books, or other definitive sources. There is a lot of information out there.
  • Don't make people guess at what you are trying to say; we are not mind readers. Be clear and concise.
  • Spelling and grammar are not rated, but they do make a post easier to read.
See more
See less

MFM emulator, zrqch0 and friends - some notes

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    MFM emulator, zrqch0 and friends - some notes

    I have been running a couple of mfm emulator boards (http://www.pdp8online.com/mfm/) for a while now. Most things working very well. At present all on 11/73 and 11/83 with BSD2.11 as the OS - but I have plans to move to older kit once I get an understanding of the MFM and what it does.

    First: hats off to some very nice kit. If YOU do what it says on the tin, then IT does indeed do what IT says on the tin.

    After that I wandered off into a few areas that gave me trouble - with the old XXDP dec formatters.

    Others may have seen these problems from different angles and be able to help.

    For those who have not seen them and head in an "MFM emulator" direction it may save you time and frustration.

    Background
    11/73 with RL02s and an M7555 (RQDX3 controllers).

    I have no trouble using the emulator to "image" an existing disk and then use that on the 11/73. Works a dream. I have copied 4 old RD5x type disks onto the beagleboard - and backed them up to my linux system with no problems.

    Then I decided to make a "disk" from scratch - without reading in an existing drive,

    Ttry as I might I just could not get the dec formatter ZRQCH0 to format the "emulated disk".


    DR>STA

    CHANGE HW (L) ? Y

    # UNITS (D) ? 1

    UNIT 0
    Enter controller IP Address (O) 172150 ? 172154
    What unit do you want to format [0-255] (D) 0 ? 0
    Would you like to revector a single LBN only [Y/N] (L) N ? N
    Do you want to use the "AUTOFORMAT" Mode [Y/N] (L) Y ? N


    Would you like to use the RCT - Revector known bad blocks [Y/N] (L) N ?


    **** WARNING ****

    ALL DATA ON SELECTED DRIVE WILL BE DESTROYED

    Write protect all drives not being formatted.
    Please verify that the selected drive is ON LINE
    and NOT write protected.

    If formatting RX33 media, insert media to be
    formatted in the selected drive.

    Do you wish to continue [Y/N] (L) Y ? Y


    MSCP Controller Model: 19
    Microcode Version: 4


    Formatting of Diskette on Drive 0 Begun.

    ZRQC SYS FTL ERR 00007 ON UNIT 00 TST 001 SUB 000 PC: 105742
    Controller has reported a fatal error in the FORMAT program.
    Status: LBN format error (drive FORMAT command failed)

    Drive 0 was not formatted successfully.

    ZRQC EOP 1
    1 TOTAL ERRS



    (and a thousand other attempts with Y and no and and and)
    So errors - some versions of the formatter produced errors about no Unit Information Table.

    But other folk on the web had prompts about "make a new one".

    So I moved from my trusty XXDP2.5 back to XXDP2.2 - same issue
    I went to an XXDP1 disk - no ZRXC?? of ANY sort!

    damn it.

    rummaged and rurached on the web, dunted my heid off the desk a few times. Perhaps ZRQCH0 I was running was not the unique and only ZRQCH0.
    I KNOW that the 0 should be a release and 1 for a different release.

    Anyway I found a bunch of other rl02 images on the web, downloaded them and one by one dd'd them into an RL02.
    One of these downloads had an image that did more sensible things
    DR>START

    CHANGE HW (L) ? Y

    # UNITS (D) ? 1

    UNIT 0
    Enter controller IP Address (O) 172150 ? 172154
    What unit do you want to format [0-255] (D) 0 ?
    Would you like to revector a single LBN only [Y/N] (L) N ?
    Do you want to use the "AUTOFORMAT" Mode [Y/N] (L) Y ? N


    Would you like to use the RCT - Revector known bad blocks [Y/N] (L) N ?


    **** WARNING ****

    ALL DATA ON SELECTED DRIVE WILL BE DESTROYED

    Write protect all drives not being formatted.
    Please verify that the selected drive is ON LINE
    and NOT write protected.

    If formatting RX33 media, insert media to be
    formatted in the selected drive.

    Do you wish to continue [Y/N] (L) Y ? Y


    MSCP Controller Model: 19
    Microcode Version: 4

    Do you want to use manufacturing bad block information [Y/N] (A) N ? N

    Downline load UIT [Y/N] (A) Y ? Y


    UIT Drive Name
    __________________________________________________ _____
    0 RD51
    1 RD52 part # 30-21721-02 (1 light on front panel)
    2 RD52 part # 30-23227-02 (2 lights on front panel)
    3 RD53
    4 RD31
    5 RD54
    6 RD32
    7 RD33

    Enter Unit Identifier Table (UIT) [0-7] (D) ? 5

    Continue if bad block information is inaccessible [Y/N] (A) N ? Y

    Please type in the serial number [8-10 digits] (A) ? 2222211111


    Formatting of Drive 0 Begun.


    ------------ FORMAT PROGRESS REPORT -------------


    1 minute into format ---- Formatting tracks, LBN # 34613
    2 minutes into format ---- Formatting tracks, LBN # 68885
    3 minutes into format ---- Formatting tracks, LBN # 103242
    4 minutes into format ---- Formatting tracks, LBN # 137310
    5 minutes into format ---- Formatting tracks, LBN # 171650
    6 minutes into format ---- Formatting tracks, LBN # 206007
    7 minutes into format ---- Formatting tracks, LBN # 240075
    8 minutes into format ---- Formatting tracks, LBN # 274721
    9 minutes into format ---- Formatting tracks, LBN # 309061
    10 minutes into format ---- First check pass, writing LBN # 35428
    11 minutes into format ---- First check pass, writing LBN # 70618
    12 minutes into format ---- First check pass, writing LBN # 105808
    13 minutes into format ---- First check pass, writing LBN # 140998

    Success!

    The disk that did the trick for me had an md5sum of 0c5c788d406b3ee6e27c3ebbd13f206a for the 10meg uncompressed file
    and a unix sum of 23864 10240
    and a dir list of the form
    775 ZVTMA0.BIN 19-SEP-81 29 034517
    776 ZVTNA0.BIC 19-SEP-81 13 034554
    777 ZVTOA0.BIC 19-SEP-81 19 034571
    778 WUZ24 .CNF 1-JAN-70 2 034741
    779 WUZ24 .MAP 1-JAN-70 2 034743
    780 DECX23.BIC 2-JAN-70 66 034747
    781 DECX23.CNF 2-JAN-70 2 035051
    782 DECX23.MAP 2-JAN-70 9 035053
    783 FERRER.LIB 2-JAN-70 2 035064
    784 FERRER.BIN 2-JAN-70 73 035066
    785 GAMMA .CNF 2-JAN-70 2 035177
    786 GAMMA6.BIN 2-JAN-70 95 035201
    787 GAMMA6.CNF 2-JAN-70 2 035340
    788 GAMMA7.CNF 2-JAN-70 2 035342
    789 GAMMA7.BIN 2-JAN-70 95 035344
    790 ZRQCB2.BIC 10-MAR-86 28 035503
    791 ZRQCH0.BIC 23-AUG-88 73 035537

    I dont know where I downloaded the disk from - dulich - too late at night and two tired, and my notebook degenerated into doodles.

    Note the 2 files "at the end" of the DIR way out of date sequence.


    So,
    I can now create a RD disk with 2048 cylinders,16 heads and have a humungous 280Mb disk on the MFM controller.

    I hope this saves someone else the time it took me to rummage about.
    Soon I will be trying the DX2 controller and then back into the mists of time on older processors ....

    #2
    Did you try with this version?

    http://www.bitsavers.org/bits/DEC/pd...xxdp25.rl02.gz

    .DIR ZRQC*.*

    ENTRY# FILNAM.EXT DATE LENGTH START VERSION

    636 ZRQCH0.BIN 1-MAR-89 72 035016


    I don't have one of the MFM emulators yet myself to test. I plan on getting at least one from the next batch that is available.

    Comment


      #3
      I am really sorry I dont know ;-( Bad science, no notes in my log book
      I think I downloaded 2.2 and 2.5 from that site.
      I have

      The md5sums are
      0c5c788d406b3ee6e27c3ebbd13f206a xxdp+1.rl02
      fd79b7a8d7d0d752a8052463c3f399e8 xxdp22.rl02
      04845865c63bcc912d7dee922ce9ac59 xxdp25.rl02
      253216f8c81f125f1fd35e0ae6a30d88 xxdp+.rl02
      and
      23864 10240 xxdp+1.rl02
      59679 10240 xxdp22.rl02
      35180 10240 xxdp25.rl02
      31081 10240 xxdp+.rl02

      Just downloaded them, I get
      [root@jondev Downloads]# md5sum xxdp*.rl02
      fd79b7a8d7d0d752a8052463c3f399e8 xxdp22.rl02
      04845865c63bcc912d7dee922ce9ac59 xxdp25.rl02
      So if I dont have those ones I have something cloned from them or vv.

      The file I am calling xxdp+1.rl02 is the rl02 image that worked well for me.
      Up until now I have only ever formatted a "real" dec disk, so the UIT block(s) was not an issue and both 2.2 and 2.5 worked for me.

      I dont think ANY of the 2.5 images I have used worked on on an mfm emulated disk that was created without cloning a real mfm disk.
      The 4 above are the ones that currently exist on my rl02 packs.

      I can highly commend djg's board. Living in Scotland I could not get the "whole show" in a oner. I had to get a Beaglebone locally and set it up. I was not sure how messy that would be. It was not, the manual worked fine and the conjuction of boards worked fine.

      What really beats me is if that I import it directly from the States I am a terrorist looking for that encryption technology. If I buy it over the counter in Scotland using untraceable cash I am not a terrorist!
      Your laws are as daft as ours!

      Comment


        #4
        I have tried one of these emulators, allthough not with a PDP. This is my experience:

        On my unit the low-level format was also a bit of a hassle. Not because the formatter, but because I had missunderstood the role of the Drive 2 ID jumper. Having it set without actually having the second drive headers connected to anything somehow caused a lot of fail. Usually "Drive not ready".

        But once I realized and fixed the problem, the emulated drive would successfully low-level format in a PC/AT. I then had to write to all sectors in the target machine, and after that it has worked flawlessly ever since. I'm very happy with this device!

        The reason I had to do the low-level format in an AT was because the target machine never had a low-level formatter. If you waned a HDD with this machine, the original disks came pre-formatted and pre-installed from the factory, and the designers assumed the consumer didn't need to perform any formatting at all. Of course I could have written a WD1010 low-level formatter myself, but using the PC/AT was a much easier solution.
        Last edited by per; November 8, 2015, 01:39 PM.
        Current systems owned by me:
        Vintage:IBM PC/XT submodel 087 ( 1983 ), [Kon]tiki-100 rev. C (1983), Compaq Portable I ( 1984 ), IBM PC/XT submodel 078 ( 1985 ), IBM PC/XT286 ( ~1986 ), 3x Nintendo Entertainement Systems ( 1987 ).
        Obsolete:Commodore A500 ( ~1990 ), IBM PS/2 model 70/386 type 8570-161 ( 1991 ), Atari Lynx II ( ~1992 ), Generic Intel 486SX PC ( ~1993 ), AT/T Globalyst Pentium w/FDIV bug MB ( 1994 ), Compaq 486DX4 laptop ( ~1995 ).

        Comment


          #5
          "Your laws are as daft as ours!"

          Given that we are cousins separated by a common language this should not be surprising.

          As to whether or not our House of Representatives and Senate have a higher or lower percentage of looney tunes than your equivalent legislative bodies I have no comment. To quote one of our legislators, "furthermore I have no comment regarding why I have no comment."

          Or my personal favorite from Sen. Pryor: "You don't need to pass an IQ test to be in the Senate".
          "It's all bits on the bus, Cowboy! It's all bits on the bus!" -- Tom Beck, #1ESS Instructor, Southern Bell Opa Locka Training Center

          Comment

          Working...
          X