Recent content by jlang

The system controller is the only device allowed to drive IFC (interface clear) I expect the jumper is set to allow the PET to be system controller.

I figured out where I got the MSCP boot. I ripped it out of SIMH. SIMH boots by loading a bootstrap image into memory then executing it. So that image can be loaded via ODT

I boot a RQDX3 using ODT. The MSCP boot code is 65 words. I can't find the code online at the moment. I know it's out there...

I've seen how this stuff gets disposed of. The instruments are stacked on a pallet. The cables/pods go in a big box. The pallets get sold (cheap). Nobody bids on a box of random cables. They never go the same direction after that. Sad really.

I use minicom as a terminal for a PDP-11/2. I wrote a small program that minicom calls that sends The bootstrap to ODT (with delays) You will get tired of typing the bootstrap real fast. The RQDX3 will work in a 16 bit backplane.

When I start a project is gets a Steralite box all it's own. The parts ,code and drawings collect in the box until I have enough to build. It took 30 years for my Frankenstein PDP-11 and it still needs a chassis. I have several (3-5) projects in process at a time. Very few of my projects are...

I have a MS-DOS system I run trumpet NFS on. Mount file shares from linux. Linux is also running SAMBA for the one windows box. The footprint for NFS is pretty small and you can load hi if your system can do that.

Thats a better starting place to get 50 and 60 hz.

You cant get there with a 16 bit counter. You would need to prescale the clock to the timer. The lowest clock divisor is 8. 3579545 divided by 8= 447443.125 not a good starting place to get to either 50 or 60 hz. You could use a lower divisor and do additional division in the interrupt...

I don't expect to be able to pull a color burst crystal far enough off frequency to get an integer divide for 50 hz. Several of the common baud rate crystals would work If you change the timer divisor. Can't do it with just a jumper. joe

I have to agree. A long while back I noticed a board for sale on Ebay. listed as a random board from a x-ray system. Random 8 digit part number. No useful information. I recognized the q-bus shape and a NCR5380 SCSI chip and 50 pin connector. That had to be some sort of SCSI host bus adapter...

I remember in the 2000's we would go to a location we hadn't been to in a long while only to find the Cisco router circuit board sitting on a small pile of plastic bits. Some plastics just don't hold up well. The router was still working.

That's nearly the same as what I do. I drill a pin hole (or two) across the break and insert metal pins and glue (two part epoxy) I had a hinge pin that broke (disk drive door) I drilled out hinge pin and replaced with a brass rod (and epoxy)

I'm firmly in the machine pin camp. But this is very important: Only use good sockets. I only buy Mill-Max. (yeah expensive) I've never had to replace one. I've never had an IC work loose. I agree. Never plug a square pin into an IC socket.

I put the CF card in a usb adapter. I can mount the device directly to simh. (I use this for PDP11 images) I use cpmtools to build or modify CP/M images. You can work directly with the device or work on an image and copy to the card. I'm running MacOS. I have also done this with a Raspberry...