Accessing a TK50 or TK70 from RT
rodsmallwood52 at btinternet.com
Sun Jun 12 14:49:08 CDT 2016
On 12/06/2016 19:18, js at cimmeri.com wrote:
> On 6/12/2016 12:00 PM, Rod Smallwood wrote:
>> On 12/06/2016 16:19, Jerome H. Fine wrote:
>>> >Rod Smallwood wrote:
>>>> Firstly one important fact that I did not know. If you bulk
>>>> erase a TK50 you can turn it into a TK70 tape with an INIT.
>>>> Thank you I did not know that.
>>> A bulk erase was the first thing that seemed to be the solution
>>> since I had, fortunately, found a blank TK50 tape and was
>>> able to use it to both read and write in a TK70. There was
>>> a long discussion, probably a decade ago, about CompacTape,
>>> supposedly just for the TK50, and CompacTapeII, supposedly
>>> just for the TK70. From a Memorex internet site, probably over
>>> 10 years ago and long gone now, there was a table of all of the
>>> physical characteristics of CompacTape. While the tapes for
>>> even higher density drives were different, the physical properties
>>> of CompacTape (I) and CompacTapeII were IDENTICAL!!!!
>>> So that also gave me the confidence to use the CompacTape
>>> media in the TK70 drives - which gave excellent results.
>>> Let us know if you are finally successful with the TK70 drives
>>> and tapes.
>>>> Secondly I have made a little discovery. We all know the
>>>> tapes go sticky and attach themselves to guide rollers etc.
>>>> Well its not always the tape. I have three instances of
>>>> tapes that would not feed or lace up where I got rid of the problem
>>>> without doing anything to the tape at all. In fact all
>>>> subsequent tapes have had no problems. It took 30 seconds and
>>>> apart from taking the metal cover off the back off the drive
>>>> I dismantled nothing.
>>>> If I am right and can run a load of tapes through the drive.
>>>> Then I'll say what I did. If I'm wrong then nobody will needlessly
>>>> try my method.
>>>> I will say its not cleaning the heads or the EOT sensors. You
>>>> should do that any way.
>>> It would be appreciated if you would state what you did in any case.
>>> It is always helpful to know what has been tried and does not produce
>>> a result since it can be ignored in the future.
>>>> Its clear the way to go is bulk erase TK50 tapes and then to
>>>> use the TK70 drive and controller.
>>>> Was there ever a UNIBUS TQK70 controller?
>>> I never used Unibus, so I never found out. YES!! Bulk
>>> erase is easy and does work well.
>>>> RX02 and a RX01 (I have one of each and a spare chassis)
>>>> I'll be back to them when this tape situation is sorted.
>>>> I had got to the stage where I could get commands through to
>>>> the drive electronics
>>> I have an RX02 around which I have not used in a while. My
>>> preference, if I need the RX02 hardware is to use the DSD 880/30
>>> which has an RX03 drive which can also function as an RX02 and
>>> also reads and writes RX01 media as well. My RX03 drive has
>>> been modified by placing a DPDT switch into the detection circuit
>>> for the single-sided vs double-sided sensors. That way, I can use
>>> any RX02 floppy media as double-sided without having to punch
>>> the extra holes. The DY.MAC device driver from V04.00 of RT-11
>>> contained extra code to support double-sided operation, but that
>>> code was no longer present with the V05.00 of DY.MAC when
>>> it was released in 1983. So I added the code back and that
>>> made the DYX.SYS device driver under RT-11 able to support
>>> double-sided RX03 floppies. However, the boot code is still
>>> a bit stupid and can't boot a monitor file which is partly at the
>>> end of side 1 and continues onto side 2.
>>>> RD53 - Yes out of a bag of scrap drives I managed to get the
>>>> remains of a bump stop out and replace it.
>>>> It produced one good drive which boots RT-11 every
>>> I still have a few RD53 drives around which I stopped using.
>>> I also converted a couple of Micropolis 1325 drives to
>>> RD53 drives by adding jumper R7. I really don't use
>>> my PDP-11/83 very much since Ersatz-11 is really so
>>> much more convenient and my goal for RT-11 is only
>>> software bug fixes and enhancements.
>>> Jerome Fine
>> Thanks Jerome
> Trim on long bottom posts, please. Especially if there's nothing
> interesting added at the bottom.
> - J.
..--.. I trimmed it to a one line answer. That's as short as I can go
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