On Oct 6, 2013, at 14:29 , William Donzelli <wdonzelli at gmail.com> wrote: Both "the right price" and it being on the opposite corner of the country from me mean that I probably won't be the one to buy it, but your mention of it does make me curious: What does it take to power an 11/750 or 11/751? I don't think I could practically power an 11/780 at my home, but I'm wondering what the upper limit of bigness is for DEC machines that I might procure. I presently have a VT-241 and a modest pile of RL02 cartridges, and I would like to connect them together someday. So, any DEC machine that would reasonably use RL02 drives is a possible future acquisition target, but only if I can manage to house, power and cool it. I have a 200A 240V single phase panel in my workshop, and I could make up to 10kW of 3-phase power with a military surplus generator set that I have. For anything that might go inside my house, I think the upper power limit would be either the 240V 20A circuit or the 120V 30A circuit that I plumbed into my radio room to run transmitters. -- Mark J. Blair, NF6X <nf6x at nf6x.net> http://www.nf6x.net/

[...] Of the 3 original VAX series (11/725,11/730 ; 11/750,11/751 ; 11/780, 11/782, 11/785), the one I think is hardest to keep going is the 11/750 (or 751). The 11/780 series machines are virtually all standard ICs. There are lots of them, it is complicated. But you could probably get parts if you had to. The 11/730 series are mostly standard ICs and PALs. The PALs are not copy-protected, I think I have dumps of them somewhere. There are 2 custom DEC gate arrays for the memory ECC logic, but I think it is possible to kludge the machien if those fail and get it running, albeit without any error correction on the memory. The 11/750 is mostly those DEC gate arrays. They are custom. There is limited data on them (there's a handy little manual on bitsavers, something like the '11/750 magic book' that gives pinouts, etc). But if they faily you would probably bee looking for spare 11/750 baords to take them from. And said boards are not common. -tony

On Oct 6, 2013, at 17:26 , William Donzelli <wdonzelli at gmail.com> wrote: DOH! I didn't notice who I was replying to. Hi, William! Ok, I feel a sudden vacuum in my wallet. So, tell me... would a VAX 11/751 ever be "correctly" used with RL02 drives? Because my mission here is to connect my VT241 to my RL02 disk packs, so I need to select something that naturally uses RL02 drives (and I need some of the drives, too, of course). I had been thinking along the lines of PDP-8 or PDP-11, but nothing sucks like a VAX! Please feel free to tempt me with specifications, pictures, etc. of that 751. ;) Ugh, I'd also need one or more additional racks for disk drives and a tape drive. That would take up a LOT of room in the house. Maybe I should turn my 12' commo shelter into a machine room? Not sure if a VAX cabinet would fit through the door. PDP-* machines with switch register panels are awfully cool, but I think I'd earn all sorts of style points for running a VAX at home. I have one of those fancy new smart meters, so I would need to buy a meter socket and a mechanical meter to get the full effect. -- Mark J. Blair, NF6X <nf6x at nf6x.net> http://www.nf6x.net/

The topic of single phase vs. an 11/780 reminds me of a little prank back in college around 1990ish. I had a few part-time jobs at various times in one of the computer support organizations back then. First as a backup operator doing tape backups on a graveyard shift, then later as a consultant at the support desk doing noob-support, then later in another portion of the department doing tool builds and light UNIX programming. They paid me and everything, so it's good that I never mentioned that I probably would have done the job just for that key to the machine room and the root passwords they gave me... The best part was being able to do homework after hours on the department's Sun workstations and VAXen rather than fighting over older workstations in the EE and CS department terminal rooms. Pretty much unlimited access to VAXen, Suns, Decstations, and even a NeXT cube. No silly CPU, disk or printing quotas, and 24/7 access to the main machine room. Good times, good times... Anyway, once a friend of mine and I decided to play a prank on our boss while he was away on vacation. There was a decommissioned 11/780 or 11/785 in the machine room. We noticed that the blowers were all 120V single-phase, so we pushed the main cabinet down the hall late one evening and crammed it into the boss's office. That was a tiny office, and it barely fit with enough room to squeeze by. Then we plugged in a few fans so it sounded like it was turned on, stuck a small hard-copy terminal on his desk, and manually typed up stuff to make it look like we were trying to boot the beast. I wish I could have seen his face when he got back from vacation... Later on, in another part of that department, another vacationing boss got a TU-77 rolled into his small office and turned on. Not my doing, but that was another classic. -- Mark J. Blair, NF6X <nf6x at nf6x.net> http://www.nf6x.net/

That sucks. :-) /~\ The ASCII Mouse \ / Ribbon Campaign X Against HTML mouse at rodents-montreal.org / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B

On Oct 6, 2013, at 5:36 PM, "Mark J. Blair" <nf6x at nf6x.net> wrote: You and several dozen other people. The main constraints to such an acquisition are: 1) Finding someone with an old one who is willing to part with it (usually old factories or the like, most of whom are just going to look to a scrapper or recycler first, because who would want a decades-old hunk of steel?) before someone else gets to it 2) Paying to ship the damn thing; that's a truckload in and of itself, especially once you include the peripherals usually required for a full system 3) Figuring out where to put it (it's big) 4) Figuring out how to power it (you'll generally need 3-phase, and usually pretty hefty if you have a sizeable load of RA-8x disks) Usually #1 and #2 make it impossible for most people; if you can figure out those, #3 and #4 probably aren't insurmountable. - Dave

You guys never ran into buyers like this? http://goldchipbuyer.wordpress.com/2012/05/11/buyingprice/