From: PD82@brx.th-damrstadt.de (A.G. Schindler)
Subject: Re: RT-11 help needed
Date: Tue, 28 Jul 1992 00:32:46 GMT
X-News-Reader: VMS NEWS 1.20
Organization: Technical University Darmstadt, Germany, Computer Center

In <1992Jul27.151805.2692@cs.cornell.edu> chapman@cs.cornell.edu writes:

+>  I am trying to boot RT-11 (I have several versions: 5.1, 5.4, 4, 3b)
+>  on a pdp-11/20 (this is hobby stuff, not real work). Let me describe
+>  the system and what I have done, and perhaps someone can tell me if this
+>  is impossible to do, or what I am doing wrong. 
+>  
+>  I have one RK05 drive attached via an RK11D, but could attach as many
+>  more as needed, and a tty33 for the console (via a KL11). Memory is 24K
+>  of core in an MF-11L. That is all that is currently attached. 
+>  
+>  Previously, I have booted XXDP (diagnostic OS) by toggling in the RK05
+>  boot code by hand, putting the pack in the drive, and hitting start. The
+>  monitor comes up on the tty. 
+>  
+>  When I do this with RT-11, the read light on the drive flickers a bit,
+>  it makes sounds as if it is seeking, and the processor continues to run,
+>  but nothing happens on the tty. After about a second the disk quiets down,
+>  but still no action on the tty. So I powered down, but on power up I got
+>  a message that looked like it was from RT11 saying that a power failure
+>  had occurred. What do I need to do, or do I need other hardware? I also have
+>  a collection of paper tapes labelled "RT-11 Sources" -- what on earth are
+>  these? 

1.) If XXDP does run and ANY other system does not, it is very likely, there's
    something wrong with youe interrupt configuration, as XXDP does not use
    ANY interrupt (it simply polls, this is why everyting You do on floppy
    lastst so veeery long)

2.) 11/20, the first of all commercially sold 11's has some nasty habits
    about dealing with auto-increment/-decrement, it has no EIS and the
    priority of harware traps is slightly different to the modern types.

3.) The disks start to work, this shows, that (parts of) the boot procedure
    is/are coming up. If the disk lamp is flickering only short time (2 sec
    or less), the system is not atually booted up, but dying inside the
    primary or secondary boot. If the flicker lasts longer, You should 
    ALWAYS get a startup Message as <RT-11 Vxxx>. After issuing this
    Prompt, the system executes START?.COM. If You don't get any console-
    message, check if You are booting a customized system with all
    startup messages disabled. Many systems used in factory-control are
    customized like this !

4.) Maybe the ammount of memory (24k) does not match a SYSGEN special
    feature, which allows to enable the lower 2 kW of I/O page to be
    used as additional memory. This was common use in 32 kW RT11SJ
    systems on Q-Bus machines (and only there!), where free memory was
    always rare.

5.) Put the "Source Tapes" in Your Gemm's-Box, togeter with the other
    precious ancient things (but avoid to use them).

    Moral: If You have the resources, try to boot a virgin system, 
           preferably RT11SJ, the single job monitor, which behaves
           very friendly.

    Your's Andreas

     +-------------------------------------+----------------------------+
     | Andreas G. Schindler                |        ^   ^      The best |
     | c/o IID Schindler & Schubert GbR    |       (O v O)     is yet   |
     | Lammertsgasse 12 , D-6140 Bensheim  |     /(       )\   to come  |
     | Tel: 0 (49) 6251 62081              | ======""===""======        |
     | Net: pd82@brx.hrz.th-darmstadt.de   |                            |
     +-------------------------------------+----------------------------+

     +-------------------------------------+----------------------------+
     | Andreas G. Schindler                |        ^   ^      The best |
     | c/o IID Schindler & Schubert GbR    |       (O v O)     is yet   |
     | Lammertsgasse 12 , D-6140 Bensheim  |     /(       )\   to come  |
     | Tel: 0 (49) 6251 62081              | ======""===""======        |
     | Net: pd82@brx.hrz.th-darmstadt.de   |                            |
     +-------------------------------------+----------------------------+
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