The supply voltage does sag to around 4.6v (I am powering the whole backplane with a 4-pin molex connector on an ATX power supply), so maybe my supply current is insufficient. The supply appears to have one single shared 5v output that is claimed to be rated at 20A though, so hmmmm. I shall have to keep a closer eye on it as I continue testing.
Don't forget VTserver. A great (if slow) way to transfer a file system onto real iron through the console port.Having a "new" machine with no (working) storage device and/or no way to load software has been faced by a lot of people and solved in a lot of ways. IMHO you should check out TU58FS.
All that's required is a second serial link to allow the PDP11 to hook up with the emulated TU58 "tape device." In the case of TU58FS, the software allows the PDP11 and the host computer to share a file system. You put files on the host system's disk and the PDP11 sees the files as being on the TU58's tape. If you have fast enough serial ports you'll have what looks like a TU58 that runs as fast as a disk. You can then run RT11 or XXDP and use their tools to support testing and bringing up the rest of your system.
I am so close to having something I can do something with. I've got PDP-11 BASIC loading off a paper tape image and I can run it, but it spams a stream of READY at me endlessly. What do y'all suppose I am doing wrong here?
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basic pdp11 DEC-11-AJPB-PB.ini PDP-11 simulator V4.0-0 Current git commit id: 5a7a4c77 CPU 11/73, NOCIS, autoconfiguration enabled, idle disabled 256KB Disabling XQ load DEC-11-AJPB-PB.ptap run 16104 PDP-11 BASIC, VERSION 007A *O ? DO YOU NEED THE EXTENDED FUNCTIONS?Y HIGH-SPEED READER/PUNCH?N SET UP THE EXTERNAL FUNCTION?N MEMORY? READY 100 FOR I = 1 TO 10 110 PRINT I,I*I,I*I*I 120 NEXT I 130 END RUN 1 1 1 2 4 8 3 9 27 4 16 64 5 25 125 6 36 216 7 49 343 8 64 512 9 81 729 10 100 1000 STOP AT LINE 130 READY
basic basic md5sum DEC-11-AJPB-PB.ptap 5b128945ef2b8f3d0e0cd899805a5a68 *DEC-11-AJPB-PB.ptap basic basic cat DEC-11-AJPB-PB.ini echo load DEC-11-AJPB-PB.ptap load DEC-11-AJPB-PB.ptap send delay=10000 expect "*O " send "?\r" ; cont expect "FUNCTIONS?" send "Y\r" ; cont expect "PUNCH?" send "N\r" ; cont expect "FUNCTION?" send "N\r" ; cont expect "MEMORY?" send "\r" ; cont expect "READY\r\n" send "100 FOR I = 1 TO 10\r110 PRINT I,I*I,I*I*I\r120 NEXT I\r130 END\rRUN\r" ; cont echo run 16104 run 16104 basic
I agree that there is a vast and somewhat sad level of disinterest in the low-spec LSI-11 CPUs and that nobody is likely to begrudge you a couple traces.Some steps forward, some steps back.
My MSC 32kW card seems to have stopped working suddenly. Bus timeouts. But I shall rearrange some cards and retest I suppose, with various termination and refresh signals.... I'd tested it with the qbone as bus master (no cpu) the other day and it tested fine, but now it won't respond at all. D:
With 12kW of Heathkit SRAM installed, everything hangs trying to boot, even though all the ram on those cards tested good. Weird. I guess I need to retest them.
My 2mb cards arrived yesterday. With one of them installed, various OSen seem to boot as they should. Although I cannot use more than 128kW until I wire wrap the backplane to 22 bits.
On that topic:
Unless I am full of poo, according to the documentation BDAL18..21 on the 11/2 CPU expose some troubleshooting signals or somesuch on the backplane. So if I wrap the backplane for 22 bits, I fear that trying to test stuff with the 11/2 in there will cause trouble. This leads me to think that maybe I should just cut the traces on the 11/2 card that connect to the BDAL18.21 pads on the edge connector, and then it will work in a 22 bit backplane without causing hinkiness. Would this be sacreligious? I'd hate to be excommunicated before the project is done, but on the other hand I kind of have a feeling that nobody really cares about the low-end CPUs. I'm happy as long as the modifications are documented and that documentation and all the original hardware stays with the H11 and all goes on to the next guy as a unit someday when I get mauled by a bear or something.
I'm pretty fond of my time playing Infocom games on an 11/03 with a RX01, it made charming crunchy noises.
For the low-spec system I'm fond of the smaller q-bus chassis, the one the 11/03 tended to come in, the little one DSD made, or in the extreme the 4-dual-ht box dec made or the one tucked into a VT-1xx chassis.Exactly this. I want to run 2.11BSD and RSX11M on the H11, and put something together pretty low spec with what's left to run RT-11 for text adventures and BASIC and such. I'm not sure what to do for an enclosure. I have a gutted-except-for-the-CRT TRS-80 Model 4 and an extra video board from a Model II that I think would work on that CRT. Might be interesting to try to drive it with a custom FabGL timing or something. But that's a bridge to fall off of when I come to it.
Unfortunately I don't have any qbus floppy controller (although I do have a nice spare 8" drive in a very broken Tektronix 11/23 clone). There was a Zenith-branded dual 8" unit with controller that I could have gotten with the H11, but it was more expensive than it should have been and it's getting pretty hard to find reliable 8" media. But if I could scare up some sort of fairly flexible Shugart controller and some nice chunky full-height DS/DD 5.25 drives, I have more than enough well-preserved media for something like that. Maybe an H77 drive enclosure if I could find one.
I recall a 1.2Mb 5.25 bring a popular swap for an 8" in the big Tandies, but it's getting pretty hard to find good 1.2mb 5.25 media these days too.......
I guess I'm going off on a tangent, but I can't seem to get used to the silence of the floppulators. I have a clicker on the FloppyEmu on my Apple II, but it's not the same (it just snaps a relay one way or the other depending on whether or not one of the stepper lines is activated). It would be a really dumb project, but sometimes I think about sampling actual floppy and hard drive sounds and trying to make some kind of contraption with an atmega32 or something that would sniff on the disk drive interface and play the appropriate proper sounds over a carefully placed hidden speaker, heh.