RT11 sysgen and disk partitions

Jerome Fine replies: Also, if the device driver is LOADed (or Resident - i.e. system device), then the SET commands for DU(X).SYS will not take immediate effect. Some device drivers do, but DU(X).SYS do not. You must first UNLOAD or BOOT. If the SET commands prevent a BOOT, you are stuck until you can fix them from off that partition. If you need help, I can suggest a way. Easy, but time consuming and open to an error in some cases. So be careful if you are making changes to any bootable device drivers for any RT-11 partition. I think that FB will work as well in most cases, but NOT RT11XM! If you first: BOOT RT11FB and then try "RUN TSX", you will find out. You may need to UNLOAD other device drivers. Something is VERY wrong!! RT-11 partitions were NOT possible until V05.03 of RT-11 in 1985. Can you please confirm the RT-11 version number? If you do decide to boot RT-11 directly on power up, the required set command is: SET DUn: PORT=0, UNIT=n, PART=0 The code in the EPROMs for a hardware boot of DUn: will ONLY boot physical drive "n". Under RSX-11 and RSTS/E where hard drives do not have partitions, the above SET command does not exists, so there is no conflict. In RT-11, the user is allowed to map "unusual" relationships, so you need to understand the reasons and the restrictions. RT-11 is NOT able to do a hardware boot on a non-zero partition. (Until V05.06 of RT-11, the distributed DEC monitors could not do a software boot of a non-zero RT-11 partition due to one missing instruction in the boot program.) (Also until V05.03 of RT-11, the SET commands for DU did NOT allow RT-11 partitions.) Assuming you have one DU hard drive and an RX50, you want to use (to be able to do a hardware boot): SET DU0: PORT=0, UNIT=0, PART=0 (for the hard drive) SET DU1: PORT=0, UNIT=1, PART=0 (for the first RX50) SET DU2: PORT=0, UNIT=2, PART=0 (for the second RX50) Thereafter, the choice is yours. I usually recommend: SET DU4: PORT=0, UNIT=0, PART=1 (second RT-11 partition) SET DU5: PORT=0, UNIT=0, PART=2 (third RT-11 partition) Remember, until V05.06 of RT-11, you can't boot DU4: or DU5: The above information applies to distributed DEC software. I have fixed some of the early versions, but it is of interest very rarely and only to software fellows who use very large hard disk drives. I finally managed to obtain some Hitachi ESDI DK515-78 600 MByte hard drivers which manage 20 RT-11 partitions EACH. The Maxtor XT8760E also had that capacity as well. I hope this helps. Ask some more if you have other questions. You ca experiment with the correct values of the SET commands while you BOOT from DL0:, after which you can copy the DU(X).SYS file to the DU partition along with the monitor you are going to use. The command: COPY/BOOT DU0:RT11FB.SYS DU0: with then set everything up on the DU partition. As long as the DL0: partition is still available, then any mistakes can easily be corrected when you BOOT from DL0: A word of caution is to never change both at the same time. As long as you can boot from one, it will be possible to fix things. You can also use VM: as a temporary RT-11 partition and experiment separately with RT11FB and RT11XM since the device drivers are separate. You can copy all the *.SYS files to VM: and then: BOOT VM:RT11XM even if you were running RT11FB as long as you make sure that the "base" for both VM.SYS and VMX.SYS are identical. With a 4 MByte memory on the PDP-11, there are 4096 blocks available using just 2 MBytes of the PDP-11 memory or much more than needed for all the SYS and SAV files, let alone other files for a working RT-11 system. It sounds like you have a non-DEC controller which emulates MSCP. I use and ESDI version myself with Hitachi DK515-78 600 MByte drives with 600 MBytes. The controller is the Sigma RQD11-EC quad ESDI controller which can handle 4 ESDI hard drives. The RQD11-EC emulates MSCP under RT-11. That should be easy to fix. I suggest you ask on the list for an extra cable. I seem to remember that the cable you need is the same as the normal cable (that you are probably using right now) between the part attached to the 40 pin cable that is then attached to the RL02 controller at the other end. Just move the terminator to the bottom connector on the second drive and connect the first RL02 drive to the second RL02 drive - connect the bottom connector on first drive to the top connector on the second drive. It is usually sufficient under RT-11 to have 2 RL02 drives if you have a few spare RL02 media for backup. A TK25 is also not bad, but MSCP drives, especially an MSCP magneto optical such as a Sony SMO S-501 is really great. Unfortunately SCSI Qbus host adapters are still a bit expensive. I would never use a TK50 as a backup drive since comparing the file written to the TK50 tape with the original file takes too long. A TK70 is acceptable. 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.