Recent content by czunit

I'll be darned, glad you got it working! My Pro 350 and two 380's do not need a floppy in the drive to boot. Out of curiousity, if you pull the RX50 card does it boot normally off the disk?

Also I'll bet ChatGPT is thinking you have a Sun 3 or 4 or something where there are billions of articles on the battery dying.

I wonder about that. If you ever want to send your RX50 controller for me to test let me know.

My Pro/350 batteries were dead for decades (they still work), the problem is not NVRAM. It's possible the HD is bad, have you loaded the image on XHomer to see if it boots? The RX50 drive would need at the least a nice cleaning, relube of the head screw, and probably new or re-glued pads on...

I'd almost say start with the keyboard. If it says press resume to continue and it doesn't work something is up with the keyboard. Have you tried removing the RX50 controller? Isolate the problem as much as possible.

Yep, looks like I have a buyer. Which is good, as otherwise this thing would attract a Cipher 880 or some other Pertec tape drive. Which I so do not need.....

DQ15(3) sticker rev D

DQ15 Q-Bus tape controller. First $50 gets it plus USPS Priority Mail. US please.

Note, those ferro resonant capacitors run at a very high voltage and can pack a fatal wallop if the terminals are touched. Discharge with screwdriver and cover the terminals so you can never touch during operation. (These are used on the Elec-Trak charging transformers. Amazingly stable, good...

Back when I had to have an 11/34 professionally cleaned after being in a room with a smoky fire the cleaning company (they were certified to clean RM02/03/05 packs among others) used deionized water. A *lot* of it. System worked perfectly afterwards for years.

Depends. I have running TK50/70 drives on the pdp11's here. What's on the tapes?

Only thing I would recommend is using PETG instead of PLA if you want a really strong handle. For a single flip chip I think PLA is fine though.

Hm. I seem to recall that DMA on a PMI system goes from device to memory directly (over the Q22 bus with the usual burst mode stuff) and the pdp11/73's cache just snoops the transaction and invalidates any pages in cache that were written to by the DMA device. The double word read trick of PMI...

I've had good luck with CA adhesive with the stuff you rub on the plastic first. Lock-tite sells it, works surprisingly well for a lot of plastics.

It is a weird controller, no doubt. But maybe the problem is in the RD50; do you have a Gesswin tool to try checking it out or emulating.... well anything better than an RD50?