WTB: RX02 Floppy Disks

Ulrich Tagge u.tagge at gmx.de
Thu Aug 3 16:28:25 CDT 2017

Hi All,
All my 8" SSDD /SSSDdisks are non formatted, which was the reason for my 
initial troubles.
Nevertheless, my IBM System /23 (Type 5324) can format disks in three 
different formats:

_1. IBM System /23 Format_
512 Bytes per Sector
Possible Disk: SSSD, SSDD, DSDD

_2. Standard Format_
128 Bytes per Sector
Possible Disk: SSSD, SSDD

_3. H- Format_
258 Bytes per Sector
Possible Disk: DSDD

_So option 2_ was the right one, also when nothing in the docs point to 
the IBM 3740 format.
After booting the System/23 with the inserted maintenance Disk VOL002 
the formatter program can be started with the following command: link 

By now I have 20 RX02 Disks formatted, and was also able to create a 
bootable RT11 Disk via my running RT11 installation on my RC25.
It is RT-11SJ (S) V04.00I ...
DY1:/FORMAT-Are you sure?Y
?FORMAT-I-Formatting complete
DY1:/Initialize; Are you sure? Y
?DUP-I-No bad blocks detected DY1:

Next step would be to install RT11 on my SCSI Disk, which is presented 
through a Dilog SU726A as MSCP Device 0 (Address 160340 (will be 1760340 
on my PDP-11/84)) to the system.
Disk is an DEC RZ22 and was also formatted and mapped, through the Dilog 
"BIOS" (Jumper J14 in to boot Maintenance Address ... and @175000g 
followed by FT)
Now it looks like I need the SU726A manual, as I have no clue as which 
device RT11 should recognize the Dilog, I assume DU0: but RT11 doesn't 
load the Device.


Device      Status       Vector
   US      Not installed  410
   DL      Not installed  160
   DU      Not installed  154
   RK      Not installed  220
   DY      Resident       264
   DX      Not installed  264
   LP      146676         200 204
   SC      143332         000
   HC      Not installed  330 334
   BS      Not installed  300 304
   VW      Not installed  270 274
   NL      Installed      000
   LS      Installed      200 204
   MS      Not installed  224
   MM      Not installed  224

SWAP  .SYS    25  26-Nov-91      RT11SJ.SYS    65  26-Nov-91
US    .SYS     7  26-Nov-91      TT    .SYS     2  26-Nov-91
DL    .SYS     4  26-Nov-91      DU    .SYS     4  26-Nov-91
RK    .SYS     3  26-Nov-91      DY    .SYS     4  26-Nov-91
DX    .SYS     3  26-Nov-91      LP    .SYS     2  26-Nov-91
SC    .SYS     5  26-Nov-91      HC    .SYS     5  26-Nov-91
BS    .SYS     3  26-Nov-91      VW    .SYS     2  26-Nov-91
NL    .SYS     2  26-Nov-91      LS    .SYS     2  26-Nov-91
SCMEV .SYS     5  26-Nov-91      SCVS11.SYS     4  26-Nov-91
SCEVA .SYS     4  26-Nov-91      LPMEV .SYS     2  26-Nov-91
LPLXY .SYS     2  26-Nov-91      LPSID .SYS     2  26-Nov-91
LPEVA .SYS     2  26-Nov-91      MS    .SYS    10  26-Nov-91
MM    .SYS     9  26-Nov-91      HC7221.SYS     4  26-Nov-91
HC7220.SYS     5  26-Nov-91      HC722T.SYS     5  26-Nov-91
US460 .SYS     7  26-Nov-91      US410 .SYS     7  26-Nov-91
HC7580.SYS     5  26-Nov-91      HC7550.SYS     5  26-Nov-91
HC7475.SYS     5  26-Nov-91      HC722C.SYS     5  26-Nov-91
SCMPR .SYS     5  26-Nov-91      CHKPNT.SYS   412  09-Aug-94
STARTS.COM     1  26-Nov-91      PIP   .SAV    23  26-Nov-91
DIR   .SAV    17  26-Nov-91      DUP   .SAV    41  26-Nov-91
RESORC.SAV    15  26-Nov-91      FORMAT.SAV    19  26-Nov-91
  42 Files, 759 Blocks
  215 Free blocks

Any Hint how I get RT11 load the correct device so that I can format and 
init the SCSI Disk?
Is maybe Someone here with an Manual of the Dilog? A SU723 could be also 
helpful, ... .

Many Greetings

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