If you want a different box or boards, feel free to contact me off list. Where are you located?
On Wed, Aug 30, 2017 at 11:02 AM, Douglas Taylor via cctalk < cctalk@classiccmp.org> wrote: > On 8/30/2017 5:53 AM, Pete Turnbull via cctech wrote: > >> On 30/08/2017 05:29, Douglas Taylor via cctalk wrote: >> >>> I'll send along a picture of the rear of the back plane. I'm getting >>> the impression I can't do what I want with the old cpu cards, M7270 >>> and M7264. >>> >>> I had really hoped to be able to put together a simple system to >>> demonstrate the differences in processing power between the 11/2 cpu, >>> the 11/23 and the 11/73. >>> >>> They are all dual width cards and it would have been simple to swap >>> them out. I think to do it I would need 2 boxes, one with a 16 bit >>> backplane and the other with a 22 bit backplane. >>> >> >> I don't see why you couldn't do what you want with the BA11-M and a >> little work, *providing* the Emulex UC07 controller works in an LSI-1103 >> system - and the manual (on Bitsavers) suggests it should. Section 1.6.3 >> says "The UC07/08 is compatible with the Q-Bus used on all LSI-11 ... >> series computers." >> >> First, you'd need to undo any backplane upgrade that made it 22-bit >> instead of 18-bit. BTW, there's no such thing as a 16-bit backplane, only >> 18-bit and 22-bit. BDAL17/18 are always bussed, to allow for the use of >> parity, even in 16-bit-CPU systems such as an 11/03. >> >> The only reason you need to do this is that the KD11-H and KD11-F >> processors put other signals on those lines, which the Emulex (and other >> 22-bit devices) won't like and will interfere with. >> >> The soldering you mentioned is almost certainly the extra four bus lines >> for the upgrade. It will be on both the B and D fingers of the backplane, >> because it's a serpentine backplane with Q-Bus on both sides. Look for >> wired connections between BC1, BD1, BE1, BF1 and between DC1, DD1, DE1, >> DF1. Check there no other extra connections; sometimes people added >> connections for other signals - for example I have a backplane with the >> SRUN signal on extra slots for diagnostics and faultfinding. Also check you >> don't have an H9270-Q, which is inherently 22-bit, instead of an H9270. >> I've never seen one, but presumably they exist. >> >> See http://www.dunnington.info/public/PDP-11/QBus_chassis for a little >> more information. >> >> Next you'd need some sort of bootstrap. What's in the custom EPROMs on >> you MXV11-AC might do. Or might not, depending on whether it uses any >> 11/23 (KDF-11) specific instructions or diagnostics, and includes an MSCP >> bootstrap. The autoboot feature on the UC07 might do instead. Or might >> not. You'd have to experiment. >> >> If you do keep the MXV11-AC, you've already got 32KB of memory that works >> with any of your 11/03, 11/23, or 11/73 processors, and you have two >> DLV11-compatible serial ports. In fact the serial ports are virtually >> identical to half of a DLV11-J. Since RT11 rarely has any use for more >> than two, you probably don't need any more. >> >> If you keep the MXV11-AC and re-enable the memory, you only want another >> 32KB, and maybe not even that. I can't remember if RT11 5.3 will run in >> 32KB; it probably will, and I'm sure it would if suitably SYSGENned. I do >> remember RT11 5.6 either didn't or didn't unless it was seriously pared >> down. Don't use anything older than 5.3 because there are bugs in the MSCP >> drivers that prevent it working with just about anything other than RQDX1/2 >> interfaces. >> >> Or you could probably use the MSV11-P. It works in 18-bit systems, and >> should still work in a 16-bit (CPU) system, but obviously you'd only be >> using the bottom 64KB. If you want "period" memory to match the 11/03, you >> could find an MSV11-DC or -DD to use instead. The -DC has 32KB to >> supplement your MXV11-AC; the -DD has 64KB. The -EC and ED versions are >> the same boards but with parity circuitry added, which makes them less >> common and more expensive, but they'd also do what you want. >> >> Hope this helps... >> >> Yes, it does help. There are 3 issues that I am trying to resolve: > > 1. Running in 32kb of memory. If I use the 32kb MXV11 can I run RT11 > V5.3? I tried this in SIMH and set the Cpu to 11/03 and memory to 32kb and > it did work. The MXV11 has PROM and is set to boot from it, but it is not > a device boot. This BA11-M was connected to a MicroVaxII and was set up to > answer telephones for the Univ of Wisc. I got this about 15 years ago and > I think I looked what was coming across the console line and I remember DL > showing up or something like that. The MXV11-AC is devilishly tough to > setup, all those wire wrap jumpers and I've misplaced my wire wrap tool. > > 2. Bootstrap. I transferred the RT11 V5.3 to a DEC 535MB SCSI disk and was > able to boot it using an Alphatronix SCSI controller, it is a Viking QDO > rebadged. It only can see 2 disks at a time, but auto configures on > startup, unlike the UC07. When I say is was able to boot it, I connected > it to a 11/53 CPU in a BA23 box just to test it out. The QDO doesn't have > a native bootstrap so that's why I began thinking about the UC07. The > manual says it has an auto-boot for LSI-11 only, but the details were few. > Someone else pointed out the modern bootstraps want to address the PSW > which doesn't exist for the 11/2, 11/03 cpus. > > 3. 18 Bit addressing. It appears that the H9270 backplane I have has been > modified by DEC with wire wrap and soldered in connections. I really, > really don't want to undo any of that. I may have to settle for just > running an 11/23, 11/53 and 11/73 cpu in this box. > > Doug > > Oh and also the usual issues: I haven't powered up this box in maybe 15 > years, I haven't tested any of the CPU cards I want to use, and I'm not > sure what I'm really doing..... > > >
