anyone ever connect a TU58 drive to a PDT-11/150 terminal port?

Chris Zach cz at
Thu May 19 05:16:07 CDT 2022

Ok. Well if all the tu58 tapes have been imaged then this should not be a problem. I can just overwrite it as needed.

I think I have a few more somewhere around here from 30 years ago.....

On May 18, 2022 9:47:18 PM GMT+02:00, Martin Bishop via cctalk <cctalk at> wrote:
>XXDP is based on DOS-11 file structures.
>Some documentary sources FoMT.
>TU58 examples of XXDP binaries, and much more, can be found at
>  the .txt files contain file structure and directory listings.
>  is a fair description of TU58 technology
> XXDP RevEng and restored sources
> I believe documents the DOS-11 file system underlying XXDP; e.g. it explains how dates are encoded.
>-----Original Message-----
>From: cctalk [mailto:cctalk-bounces at] On Behalf Of Lee Gleason via cctalk
>Sent: 18 May 2022 16:14
>To: Chris Zach <cz at>; cctalk at
>Subject: Re: anyone ever connect a TU58 drive to a PDT-11/150 terminal port?
>   Lessee...I know more about life on Mars than I do RT11, but I know from trying it myself, while building some XXDP volumes,  that a simple DIR command can't read an XXDP volume. Maybe there's an equivalent of FLX (RSX) or Exchange (VMS) on RT11? Either way, you can test your ability to read an XXDP TU58 on the PDT by doing a DUMP/TERMINAL DD0: - if it reads, it will dump the blocks out to your screen. It will be interesting to see if a real TU58 works as well on a PDT  as an emulator does.
>Lee K. Gleason N5ZMR
>Control-G Consultants
>lee.gleason at
>On 5/18/2022 3:47 AM, Chris Zach wrote:
>> Very nice to know! I am repairing my tu58 bit by bit and will try it 
>> out on my 11/150. Good to know about the serial limit, I'll jumper for
>> 2400 baud to test.
>> Question. The only tape I have for testing is an xxdp. Are they in
>> rt11 format that I can test with a simple directory command?
>> Chris
>> On May 17, 2022 11:31:55 PM GMT+02:00, Lee Gleason via cctalk 
>> <cctalk at> wrote:
>>     On 4/15/2022 2:48 PM, Lee Gleason wrote:
>>           I've been tinkering with a PDT-11/150 lately. It's a little
>>         inconvenient to work on, since it doesn't have a simple way to
>>         transfer files back and forth (KRTMIN doesn't work when
>>         transferring files to the box, just from the box, for some
>>         reason I haven't been able to puzzle out, and pasting text
>>         into a KED screen or a PIP command usually overflows my
>>         terminal emulator).   It occurred to me that the first
>>         application terminal line on the 150 is at 176500,300, the
>>         same as the default for a TU58's DL11. It's a very DL11 like
>>         interface, register wise. I'm wondering, if I could hook up a
>>         TU58 emulator and use it to move data back and forth to the
>>         150.   Has anyone had occasion to try this? Any advice on how
>>         to get it to go would  be appreciated, since I know very
>>         little about RT11.
>>         -- Lee K. Gleason N5ZMR Control-G Consultants
>>         lee.gleason at
>>        OK, replying to my own post here, on the off chance that there are any other PDT-11 hobbyists out there. I gave this a try and it works pretty well. The DD driver on the PDT-11/150 will talk to a TU58 emulator on Terminal 1 just fine (presumably, it would talk to a real TU58 as well). It only works at 2400 baud, but, it's still pretty useful for moving software on and off the box. With the "big" TU58 patch to the DD driver, it's also possible to  store lots of RT11 software or data  (65000 or so blocks worth) on a virtual TU58 and load from there, rather than switching floppies. See  for the long boring story about  figuring this out.
>>     ==
>>     Lee K. Gleason N5ZMR
>>     Control-G Consultants
>>     lee.gleason at
>> -- Sent from my Android device with K-9 Mail. Please excuse my brevity.

Sent from my Android device with K-9 Mail. Please excuse my brevity.

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