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Booting from a RX50 Floppy Drive

mc68010

Experienced Member
Joined
Aug 9, 2012
Messages
140
Location
California
Anyone know what the boot device name for the RX50 is with a RQDX3 controller on a PDP-11 ? If there is one hard drive in slot 0 I imagine it's DU0. What does that make the RX50 plugged into the removable drive port ? DU1 ? I can see the drives light turn on red for a bit then turn off during power on but, I don't here the drive actually doing a read. Hard to tell with the system noise though. If I go to the boot menu and try any sort of booting from DU whatever it doesn't even turn on the drive light again. Just gives me a ?BOOTROM-F- DU 0 device error. or DU 1 or whatever I've tried. I have (2)RQDX3 and (2) RX50 and they all do the same thing.
 
The manuals say that an RQDX3 controller searches for drives in the following order:
1 - DRVSEL3
2 - DRVSEL4
3 - DRVSEL1
4 - DRVSEL2

The RQDX3 assigns LUNs to drives without gaps in the order in which they are found according to the above search order.

The first hard drive would normally be configured with DRVSEL3 and an RX50 floppy would normally be configured with DRVSEL1 and DRVSEL2. In that case and assuming the RQDX3 is configured as the primary MSCP controller with a LUN base of zero then the hard drive would be DU0 and the RX50 would be DU1 and DU2. If the hard drive was disconnected and not found by the RQDX3 drive search then the RX50 LUNs should shift up to DU0 and DU1.

-Glen
 
Ahh I read that but, it was confusing. Now I get it. Thanks again. I continue to get this with the hard drive removed and it does access each drive:

TRYING UNIT DU1

ERROR UNIT DU0
ERR 17 NO DISK

ERROR UNIT DU1
ERR 17 NO DISK

There are actual floppies in each drive. One is a known good rt-11 non-boot disk. The other is a rt11 boot disk I made with SimH and putr. I've copied it out to a floppy, than copied the new disk back to file. The new file still booted SimH fine.

Any thoughts ?
 
How do you have the RX50 connected to the RQDX3? Through an M9058 or through a BA23 distribution panel?

Is the RX50 known to be good? Did you clean the heads? Are the disks oriented properly (RX50 is single sided, the data surfaces get oriented toward the middle of the drive.) Did you clean the sector index sensors and LEDs?

I just read the other thread about the MXV11-B. Did you get it going (is that how you're now to this point?)

Is the floppy really bootable? Under PUTR, you would need BOOT to make the floppy bootable. Did you do that?

Lou
 
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I have the RX50 connected through the BA23 back panel. I have reseated all the cables and tried a different cable from the back panel to the RX50. I haven't tried the replacing the large cable that goes to the RQDX3 yet.

I actually have 2 RX50 and both do exactly the same thing. I haven't cleaned any heads yet but, all 4 sets would have to be crummed up to all do the same thing. Possible but, seems an outside chance. I've tried all sorts of floppy disks in every slot. Always the same NO DISK error.

I have basically been working off this guide in creating boot disks: http://www.employees.org/~kirk/page0204.html#xxdprx50 but, he left off all his SimH config stuff so I have had to figure out a few things. I have also downloaded what were supposed to be bootable RT11 disk images you could just copy over with putr and "copy/file/dev" and should be bootable. They all acted the same as any random floppy even it was blank.

I have tried three different 1.2mb 5.25" drives on the Pentium box I am using to write the images. Doesn't seem to matter. However it is still the same floppy controller.

As a test I downloaded a RX50 RT11 bootdisk image. Mounted it in SimH and it booted fine. I then wrote it out to a floppy with putr. I tried it in the RX50 and got the same NO DISK error. I put it back in the PC and used putr to copy the disk to a new image. I then mounted the new image in SimH and it booted just like the original a floppy copy and image removed.

If I put the floppies in the wrong way the drive wont access them. No red access light at all. Just straight to the NO DISK error. Pretty sure I have them in the right way. Unless of course you have to write them upside down on the pc end of things. I missed that if that's the case.

This is a continuation of the MXV11-B saga but, I think it's unrelated. I actually had all this happen with the 11/73 and MXV11 and now I just repeated everything with a 11/23+ cpu instead because the boot rom is way less annoying and way faster than that MXV11 deal. I get the same results though.I guess I'll try the one other BA23 I have next.

I have two different RQDX3. One out of a MV2 and the other was out of this MicroPDP-11 system. Both do the same thing. Both have default jumper settings.

I guess the main problem is I don't have a known good working boot disk and I don't know if either of these RX50 drives are good. The other problem is that these boxes are so loud that I can't hear if the drive is doing anything other than flashing a a LED. I have tried a few times now and, even with my ear next to floppy drive, I can't hear anything over the roar of the fans.
 
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Ok, good troubleshooting so far.

If you send me a PM with your address, I can snail mail you one or two known good bootable RT-11 RX50 floppies. While I'm at it I could make an XXDP one if you know the diagnostics you want.

Also, I have a working MXV11-B / M8186 11/23 setup in my test backplane that I use for board repair. It has 145/146 roms also. Mine works fine. I can make a scan of the board and you can study the jumper settings if you like.


Lou
 
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Ok, good troubleshooting so far.

If you send me a PM with your address, I can snail mail you one or two known good bootable RT-11 RX50 floppies. While I'm at it I could make an XXDP one if you know the diagnostics you want.

Also, I have a working MXV11-B / M8186 11/23 setup in my test backplane that I use for board repair. It has 145/146 roms also. Mine works fine. I can make a scan of the board and you can study the jumper settings if you like.


Lou

Thanks for the offer. I'll PM you my address. I am getting ready to try the RX50 in my MicroVAX2. I should be able to test it under VMS and make sure it works. It's a BA123 so, it's kind of a pain but, at least I'll know if they work or not.

Anyone know if there is a OpenVMS utility that will write out these disks images to floppy ? I could try making them there.
 
I have never worked with floppies under vms before but, everything I tried tonight failed. Always the RX50 access light came on for a bit then went off and I got a "%MOUNT-F-MEDOFL, medium is offline" message or similar. Always media offline. These are all RX50 formatted RT11 disks with stuff on them. Trying to INITIALIZE them also got the media offline error.

I cleaned the heads and sensors. They weren't really dirty but, just to be sure. No change. Apparently there is a floppy formatting utility in the vaxstation diagnostics tape. Working on making one of those now but, I am not sure how good the three TK50 tapes I have are.
 
Anyone know how to boot the MicroVAX II KA-630 TK50 Diagnostics Tape ? I got the images here http://www.vaxination.ca/vms/microvax/mv_ii.html and it seemed to have no trouble making the tape. Everything I've tried got me:

?43 FILESTRUCT, MUA0
?06 HLT INST
PC = 00000EE6
Failure.
>>>

I've used a couple different tapes and they all give the same error. Other people, via google, have the same exact issue. Seems like there may have been boot flags and a boot filename given. None of the threads ever seem to come up with the answer.

After creating the boot tape I can mount it and list it out just fine.
mount mua0:/override=id
%MOUNT-I-MOUNTED, DIAG mounted on _MVII$MUA0:
$ dir mua0:[000000]

Directory MUA0:[]

SYSBOOT.EXE;1 GGSKMKAAMSG.EXE;1 GGSKMKAA.EXE;1 GGSKMMSAMSG.EXE;1
GGSKMMSA.EXE;1 GGSKMTKAMSG.EXE;1 GGSKMTKA.EXE;1 GGSKMRXAMSG.EXE;1
GGSKMRXA.EXE;1 GGSKMDHAMSG.EXE;1 GGSKMDHA.EXE;1 GGSKMXQAMSG.EXE;1
GGSKMXQA.EXE;1 GGSKMVCAMSG.EXE;1 GGSKMVCA.EXE;1 GGSKMVCBMSG.EXE;1
GGSKMVCB.EXE;1 GGSKMDZAMSG.EXE;1 GGSKMDZA.EXE;1 GGSKMKDAMSG.EXE;1
GGSKMKDA.EXE;1 GGSKMTSAMSG.EXE;1 GGSKMTSA.EXE;1 GGSKMDPAMSG.EXE;1
GGSKMDPA.EXE;1 GGSKMDRAMSG.EXE;1 GGSKMDRA.EXE;1 GGSKMDMAMSG.EXE;1
GGSKMDMA.EXE;1 GGSKMDRBMSG.EXE;1 GGSKMDRB.EXE;1 GGSKMKMAMSG.EXE;1
GGSKMKMA.EXE;1 GGSKMLPAMSG.EXE;1 GGSKMLPA.EXE;1 GGSKMTUAMSG.EXE;1
GGSKMTUA.EXE;1

Total of 37 files.
$
 
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