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

Lee Gleason lee.gleason at
Tue May 17 16:31:55 CDT 2022

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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