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TK50 various questions

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iainmaoileoin

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I have a TK50 and a few controllers. It is all I have by way of tape at this time.
I would like to see if I can get the tape to work.

I have pdp11diags etc available
BUT I cant find any diag image for the tk50 nor for the controller. Where else should I be searching?
Can anybody point me at an image?

I know folk say "throw TK50s away" "get an X/Y/Z instead" BUT I dont want to ;-)

I have no idea of the history of the controllers nor of the tape unit.
The tape unit loads/unloads tape, the pathways look clear, the wheels wheel and the rollers roll.

Ah, a thought, I made an IDC cable "straight through" to connect tape to controller - the cable is
good but should any wires be swapped?

If I toggle in some crude commands into to the CSR I can make the tape move - as yet I dont have
enuf skill (AKA time) to write C programs to start testing.

From other dimensions:
RT11 "crashes" during book when the card is present - no error messages.
bsd2.11 "crashes" (after I do a MAKEDEV tu0) and then try to access the tape (the tape does not
appear to move)
I do notice the CSR is seen at boot time and the OS claims the vector has been autoset OK.

Clearly something is borken.

I guess DEC diags would be the easiest way to fly?
Failing that, some adb or a C program running with access to kmem.
Or I will take other clues.
 
I have played with a TK50 and did get it to work properly under RT-11. The problems I encountered were not electronic in nature. I found the drive to be extremely filthy. That giant hole in the front offers the path of least resistance to ventilation air. I had to clean the entire thing, especially the mechanism. The last problem was that I had to take apart the photointerrrupter assembly on the capstan (I think). There's a slotted disk in there that had the slots covererd with dust (like having no slots). So my advice is clean everything first.

I had also read that a faster, more reliable controller to use with the TK50 is the TKQ70. I did that and was successful.

All in all, the TK50 was painfully slow and impractical compared to an emulated TU58 with expanded block size. That said, if you have a drive, you should restore it and play with it. You never know if some lost treasure will come your way on a TK50.

Lou
 
I agree with Lou on the reliability of the TK50 vs. the TK70. If your TK50 actually loads a tape, then run the XXDP diags to see if it will read and write reliably. If it does, I would label it a curiosity and save it.
 
I have a few TK50 and TK70 drives and controllers that I have pulled out of systems that I never wanted to mess with, if anyone needs some spare parts. I messed around with one once and gave up out of frustration. Have no interest in messing with them now.
 
Every system I've had the chance to install a TK50 in I've felt that an RX50 was a more practical peripheral, if that is any indication on what they are like. ;)
 
OK, I am the proud owner of a TK50 that reads and writes tapes under BSD2.11;
My first dd
#dd if=/dev/nrmt0 count=10|od -c
0+3 records in
0+1 records out
0000000 V O L 1 C O M P A I
0000020
*
0000100 3
0000120 H D R 1 0 9 0 2 9 0 .
0000140 C O M P A I 0 0 0 1 0
0000160 0 0 1 0 0 0 1 0 0 9 0 2 5 0
0000200 9 0 2 5 0 0 0 0 0 0 0 D E C V
0000220 M S B A C K U P
0000240 H D R 2 F 0 8 1 9 2 0 8 1 9 2
0000260
0000300 M
0000320 0 0
0000340
0000360

It was a nice challenge ;-)
So, I am looking for a 9 track now! Or perhaps the RX50 in the corner - but I have no media for it.

Note, the above is somebody elses data - not mine I am not a VMS fan.
 
Hi All;
iainmaoileoin, What kind of Media does it take, maybe SomeOne has something Spare they can send to You ??
In Fact, what does a TX50 look like ??

THANK YOU Marty
 
Tx50 -> rx50

Tx50 -> rx50

Marty said:
Hi All;
iainmaoileoin, What kind of Media does it take, maybe SomeOne has something Spare they can send to You ??
In Fact, what does a TX50 look like ??

THANK YOU Marty
Click to expand...

Marty, folk seem to be talking about an RX50, not a TX50. My Rx50s looks to me like a humungous floooooppppy disk. 5 1/4? - perhaps even 8.

I have no idea what it eats for lunch, but the motor on the heads looks much more like something out of my washing machine than out of a high-precision piece of peripheral engineering.

I suspect if I feed it sandpaper it will manage to record on it ;-)

Time will tell.
 
You mean the TK50? It looks like a primitive DLT drive.

120616485648-1.jpg


My Rx50s looks to me like a humungous floooooppppy disk. 5 1/4? - perhaps even 8.

I have no idea what it eats for lunch, but the motor on the heads looks much more like something out of my washing machine than out of a high-precision piece of peripheral engineering.
Click to expand...
It takes 5.25" Double Sided Quad Density disks but it can also work with regular single sided and double sided floppies as well.
 
Hi All;
Sorry about the confusion, as I have no idea of the different DEC Disk and Tape and Floppy Designations..
"" I suspect if I feed it sandpaper it will manage to record on it "" I can guarantee that it will be a very Rough Recording..

THANK YOU Marty
 
confused? you will be

confused? you will be

Marty said:
Hi All;
Sorry about the confusion, as I have no idea of the different DEC Disk and Tape and Floppy Designations..
"" I suspect if I feed it sandpaper it will manage to record on it "" I can guarantee that it will be a very Rough Recording..

THANK YOU Marty
Click to expand...
Join my club. I went from paper-tape (which I now know is a PC11) via a 64K fixed head disk (never knew what it was) via RK05s then SI disks. Somehow after that I never bothered about the names of the units.

I had a rummage in the kit box last night, it turns out I am now looking at getting and RX01 (and a dual RX02) to fire up as my next project. These beasts appear to be 8" floppies and - yes - I have no media. That may be what kills the RX project.
 
RX01 and RX02 media are standard soft sectored single sided 8" disks. Nothing special there and not particularly hard to come by. Somewhere earlier I posted my technique to make single sided sector holes in double sided disks.

Lou
 
IIRC, the issue with the RX01 and RX02 was that DEC didn't include a formatting tool making unformatted disks a challenge to use.
 
a challenge?

a challenge?

krebizfan said:
.... making unformatted disks a challenge to use.
Click to expand...
How much of a challenge? Are you suggesting one can find a way to use unformatted media? Many years ago - in a different life - I did used to do 5 1/4" controllers to "manualy" format media using the on-board controllers. This was done in a deliberately strange way in oder to defeat the script kiddies who were stealing my games software. I had a format that was so screwed up that even pro-copiers would not copy it. However when I came to repeat the process - when the source had been lost - it turned out be really clever because of a programming bug! I did manage to regenerate the program and the handling of the inter-sector gaps and and and...

Anyway, Is there any hardware on the RX01/02 controller chain to format media, or do I just bin the rx02s?
 
I think 8" disks preformatted to IBM's standard work fine with RX01 and RX02. Those used to be the easiest disks to find. Otherwise, you need access to a non-DEC drive with software that could low-level format disks. The Heathkit H-11 included a variation on the RX drives that would do the formatting.
 
"Anyway, Is there any hardware on the RX01/02 controller chain to format media, or do I just bin the rx02s? "

As far as I now - NOT.
The trick is to find a Shurgate type of 8"drive, that has a 50 pin connector.
Than you can format 8" on a normal old PC like a 386 or 468 in dos mode.
Use the 1,2M floppy disk setting in the bios.

By using a "FDADAP floppy disk adapter" 50 to 34 pin.
For more information contact info@dbit.com
http://www.dbit.com/index.html

I use an Piccolo RC-702 for that matter.
Remark The RX02 FFD's can't be read back into the DOS.
Olnly the RX01 data disks.

Think an image could be , haven't tried that.

I also use that to format disk for my DATAPOINT 1800, that also needs preformated IBM standard 8"Disks.
Know from the son of the devoloper this machine at Datapoint that they never wrote a format routine and had an
IBM machine in the halway to format disks.
Only a second formater to put more data on the disk, so the disks also not readable in the DOS pc.

Maurice
 
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