Every once in a while I feed a few "interesting" key words into the eBay search engine. Last night, I happened to find a pair of Teac FD-55F 720k 5.25" floppy disk drives for sale at a reasonable price. I think the pair I once had got sold along with an XT clone I used for my FIDO BBS back in the day. They were a neat thing to have in an XT, because they would put twice the backup data per floppy on cheap floppies (the kind sold for 360k drives, the floppies for 1.2M drives were significantly more expensive!), and with two of them you could do a full backup of a reasonable hard disk of the era quickly by loading floppies in alternating drives about as fast as you could handle them.

But the reason I've been looking for a pair is that before I put them in that XT clone, they were the drives I used on my original Ampro Z-80 Little Board running CP/M in the mid-80's. Shoveling through the stuff in the shed a while back, I discovered that I still have that board, a bunch of oddball accessories I bought or built for it, and a significant pile of floppies and documentation that all appear to be in reasonable condition.

I got a lot of use out of that system back in the day, and it would please me to have it in working order again. Fingers crossed that the drives I just bought on eBay actually work when they get here...

Managed to find my old Xeltec SuperPro and some 27256 parts buried in the far corner of the basement, and so with the help of Jonathan Engdahl's KDJ11-D/S page, my CPU board now thinks it's part of an 11/53 instead of a Decserver 550. While I had the board out of the chassis, I changed the console serial port to 38k4, leaving the second serial port at 9k6 since that's what vtserver expects.

Telling the monitor to boot from SCSI disk flashes the drive activity LED, then tells me the media isn't bootable. That makes sense since I haven't put any suitable bits on the drive yet... and suggests I may be only another serial cable away from trying to install 2.11bsd.

Occasionally, the list of things I really should be working on gets a little overwhelming. Late last night was one of those times. So, I spent a couple hours playing with the pile of PDP-11 parts...

Took the BA-11N apart far enough to extract the backplane, and added the wires necessary to support 22-bit addressing. Put everything back together, and had a bit of a scare since I couldn't seem to get the console talking to me again. Found a problem in my serial cabling, after which all was well.

Dug the DELQA out of the stack, stuck it in the chassis below the KDJ11-D/S, and confirmed that the Decserver 550 firmware still in the CPU board was able to discover it.

Extracted the CQD-223/TM SCSI board from the s-box front panel it came in, and realized it's not going to fit into the slot spacing of the BA11-N as-is. The problem is that the 50-pin header for the drive cable is straight, so by the time you put a cable on it the stack is too thick for a backplane slot. So, either I need to scare up a Qbus continuity card or something to let me skip a slot and give the card double height, or alternatively I can replace the 50-pin header with a right-angle box header and the card should fit...

At that point, I decided I'd made enough progress, and called it a night.

I found a suitable right-angle 50-pin header for the SCSI card while wandering around in the Fry's in Palo Alto earlier this week. This evening, I managed to extract the straight header without damaging the board, and installed the new connector. The board fits in the backplane just fine now... and with a power cable swiped from a dead ATX supply and a suitable SCSI cable and drive from the pile, the card still seems to work.

I need to find or make up another cable for the silly MMJ serial connectors, and then I'll be able to try loading ancient Unix...

Got word from a friend today that two RD54 drives in good condition are on the way to me, gratis. With some cabling work, I should be able to hang one or both of these on the RQDX3 and have lots of space to play with 2bsd...

The RD54 is a relabelled Maxtor XT2190, formats to about 150meg.

It's good to have friends. In the last couple weeks, I've acquired enough cards to start thinking seriously about putting the PDP-11 together. Thanks to Phil for digging a DEQNA out of his junk pile, and to Chuck for offering me a DELQA and a RQDX3.

Bummer. I totally spaced the end of auction for two QBUS SCSI controllers on eBay, one of which went for less than my max bid would have been. Oh well. Still need to find a suitable disk controller before I can do anything more with the PDP/11 system. I have a QBUS prototyping card in my stash, so it's almost tempting to clone CHD's ATA adapter, but I really just don't have time right now.

I couldn't help myself. I've found the PDP/8 family somewhat interesting for a long time, but never enough to just go out and buy one since the mass and power to fun ratio just didn't quite cut it. Along comes the gang at Spare Time Gizmos with a quasi-modern PDP/8 workalike kit...

I just couldn't help myself. I ordered one of the partial kits... the proto PCBs of the front panel for it are all sold out, but they expect to have production boards in a couple of weeks! I've also started the order process for one of the I/O boards that adds a bunch of neat features.

Yeah, it's just a toy, but the thought of having a PDP/8 clone with a real front panel, compact flash storage, etc, was way too appealing to pass up!

The BA-11N expansion chassis arrived today. Managed to scrape my left thigh getting it out of the box, no permanent harm done. As promised, it looks brand newish. Figured out how to get the cover off, then powered it up with no cards and all looked ok. The +12V supply was more like +10V, but with no load it's hard to know what to really expect.

Drilled out the rivets holding the s-box front panel hardware to the KDJ11 board, and put it into the top slot. Extracted the little front panel board from the s-box hardware, snarfed an MMJ serial cable from the vax, and the board came up! Hitting ctrl/c on the console after the LED display started alternating between E and F gave me a console monitor interface. 9600N81

So... once we have an ethernet card, it might be possible to bootload something using mopd into RAM? To what end?

The backplane in this chassis should be set for 18-bit addresses. Will need to tear the chassis apart to get the backplane out and add jumpers to connect the other 4 address bits since the CPU should be emitting 22-bit addresses.

I wonder if 1.2meg floppy drives will work with the Ampro Little Board to read my old 80-track 720k disks? I'm pretty sure my favorite drives used to be the Teac FD-55F, they appear to be unobtainable now. I also remember using some interesting two-thirds height Remex drives, 3 of them in a stack with the Ampro on top. I have no idea what I did with those drives, they probably got sold with a PC or something?