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

Chris Zach cz at
Wed May 18 03:47:07 CDT 2022

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?


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

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