11/34a restoration diary

Obviously there has been a fair amount of 11/34a traffic today what with the descriptions of the cache/fpu and CPU boards and interconnects. Armed with this info, I searched the documentation I got in the haul and found an 11/34a printset. I also did find 1) the FP11 floating point, 2) the cache, and 3) the two over-the-board connectors which would allow me to connect them to the CPU. First step was cleaning the BA box. I removed all backplanes with the exception of the primary DD11-PK backplane. The other backplanes were the VT11 without a power harness, and an RH11 backplane. I removed all the boards from the primary backplane (noting where they went). I then vacuumed the backplane, removing all sorts of dust and particulate matter, including what appeared to be degraded foam padding, which fell apart if I tried to pick it up. With the backplane as clean as I could make it, I checked the wiring harness and the backplane pins, sighting along the rows and columns looking for any bent pins. Fortunately I didn't find any. So the next step was to apply some power. The power controller in the bottom of the rack did not have a normal 115vac plug on it, so I plugged the BA box into the unswitched side of the power controller I have in the bottom of my 11/10. I tried the front panel switch... nothing... Whoops, forgot the circuit breakers in the back of the BA box. I switched those on, turned the front panel switch and I got DC OK light, and the power supply fans ran (I'd forgotten how noisy they are with the skins off the box). Power off... next step was adding the boards to the backplane, one at a time. With each board, I lengthened the amount of time I left the unit on doing the smoke test... (checking for any whisps of the magic smoke which makes electrical things work :-) I finally had the CPU (two boards), memory (MS11-LD, 128kw, 256kb) the programmers console interface, a serial line, the boot board and a bus terminator in the backplane. With power applied, I finally had the programmer's console displaying something. But when I tried to do stuff, the bus appeared hung. I turned the machine off and thought about it... 'oh yeah, I forgot the bus grant cards"... With bus grant cards in, it powered up just fine and I entered a few simple code fragments (actually single instructions) just to see if it would work. First test was a simple branch to self: 1000/777 started it, and it ran. Next, a memory clearing routine... 0/15740 15740/0 R0/160000 start at 0, it ran briefly and halted with 000002 in the display. Just as expected... memory was clear... At this point I got a little daring and moved boards around so that I could install the FPU, the cache, and the FPU and cache in successive attempts. Unfortunately it didn't work with any of those two boards in it, so I restored it to the working configuration. Slot 1 - 11/34a data paths (ABCDEF) Slot 2 - 11/34a control module (ABCDEF) Slot 3 - boot board (EF), KY11LB console interface (ABCD) Slot 4 - DL11-W (ABCD) Slots 5-9 bus grant cards (D) Slot 9 - Bus terminator (EF) I then checked the address for the console interface, hoping that the serial line unit (DL11-W) that I put in it was actually at the console address, and it appears it was. I then checked the amount of memory and found 124kw (248kb) as expected. So, bottom line is that the first day of real work was quite successful. Next step will be to find the cable I need to attach a terminal to see what sort of boot code is available. Then I'll have to try putting the RUX50 in it, attach that to an RX50 in a leprechaun box, use one of my qbus machines to build an RT-11 bootable RX50, and actually try to boot this thing. Megan Gentry Former RT-11 Developer +--------------------------------+-------------------------------------+ | Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com | | Unix Support Engineering Group | (home): mbg!world.std.com | | Compaq Computer Corporation | addresses need '@' in place of '!' | | 110 Spitbrook Rd. ZK03-2/T43 | URL: http://world.std.com/~mbg/ | | Nashua, NH 03062 | "pdp-11 programmer - some assembler | | (603) 884 1055 | required." - mbg | +--------------------------------+-------------------------------------+