Changing a plain PDP-11/23 into a PDP-11/23+

[smp]

www.jtcomputer.com
This is what they have listed on their website now. I paid less than half that as a best offer on eBay.
M8190-AB
PDP11/73 KDJ11-BB Q-BUS QUAD 15MHZ CPU MODULE WITHOUT FPJ11 CHIP (USABLE FPJ11 SOCKET, ACCEPT & RUN WITH FP CHIP)
$225.00

Along with that, I received this reply from sales@keyways.com:

Hello,

 Pricing is below:

Quantity 1: DEC M8190-AB
$275

Quantity 1: DEC M8190-AB with Cab Kit
$350

Both options are refurbished, tested, 30 day warranty

Our normal commercial price is about twice the above.

If you pay via check, we also include free ground freight.

Thanks
Mitch

This quote expires if not accepted within 10 days.
All parts are subject to prior sale.

|Over 75,000 DEC & DEC-COMPATIBLE MODULES & other parts
|    NEW - USED - REFURBISHED - BUY - SELL - TRADE
|DEPOT REPAIR - ADVANCE EXCHANGE - NEXT FLIGHT OUT SERVICE
|     30,000+ SQ. FT. OF PRODUCT AVAILABLE TO SHIP
|
| Mitch Miller
| Phone (937) 847-2300 / Fax (937) 847-2350
| (Old area code was 513)
|
| Keyways, Inc.
| 204 S. Third St.
| Miamisburg, Ohio 45342 USA
|
| E-mail: miller@keyways.com
| Web: http://www.keyways.com
| Stock List: http://www.keyways.com/stock.html

In my message, I had indicated that I am a vintage computer hobbyist, and the processor I purchase will be used in my personal PDP-11/23 for personal hobby use. That's why there is the indication that their commercial prices are double what I am being quoted.

So, it appears that:

The original eBay BIN offer for the M8189 PDP-11/23+ Processor board with cab kit will cost me $295 plus $11.55 shipping.
The M8190-AB from www.jtcomputer.com (w/o Cab Kit) will cost me $225, plus unknown shipping.
The M8190-AB from www.keyways.com (w/o Cab Kit) will cost me $275, plus unknown shipping.
The M8190-AB from www.keyways.com (w/ Cab Kit) will cost me $350, plus unknown shipping.

There are other M8189 PDP-11/23+ processor boards currently on eBay w/o Cab Kit, and w/o FPU for less money.

The M8189 processor reduces my system card count, replacing my M8186 Processor, two M7940 Serial I/O, and M8012 Diagnostic / Boot boards, but does not offer a significant performance increase (but in the eBay BIN auction it adds the FPU).

The M8190 processor reduces my system card count a bit less, replacing my M8186 Processor, only one M7940 Serial I/O, and M8012 Diagnostic / Boot boards, but offers increased processor performance. But it does add the possibility of an FPU, right?

I know for certain that the M8189 processor board will go into my system with the Q18/CD backplane (and my maximum memory will be constrained).

I THINK the M8190 processor board will go into my system with the Q18/CD backplane (and my maximum memory will be constrained).

Have I got this pretty much straight?

Thanks for listening,
smp

 

[TiggerLAS]

All of the quad boards that we've discussed will work in your backplane,
however you will be limited to ~256KB of memory.

The 11/83 thing is a little confusing at first, since it shows Q-Bus AND Unibus.
It is a Q-bus board. As I recall, DEC put a small Q-bus backplane in the 11/84 chassis,
and somehow interfaced it with the Unibus.

PMI memory can be used with the 11/73 and 11/83,
however you must make sure to ONLY use MSV11-JD (1MB) and MSV11-JE (2MB) boards.
Any other variation will NOT work in the Q-Bus.

Here's a few of the differences in the models of the CPU's -

The M8190-AB is the 15mhz 11/73+ with an empty socket for a floating point processor.
This is the "Warm Floating Point" that you've read about.

The M8190-AC is the 15mhz 11/73+ with the floating point processor already installed.

The M8190-AE is the 18mhz 11/83 with the floating point processor already installed.


Notes:

If you pay Keyways via check, then ground shipping is free.


You can usually "upgrade" the 11/73 to an 11/83, by replacing the 15mhz crystal,
with an 18mhz variety. Newer boards don't seem to have any issues with this.


I don't know what current rev FPJ11's are going for.
I seem to recall there being some issue with older revs, but I could be confusing it with something else.


With some wire-wrap wire, and some solder, you can buss the H9273,
to upgrade it to a 22-bit backplane.


As for the cab-kit for the 11/73. . . getting the cab kit is up to you.
The serial port can be set manually, and you can use a cab-kit from
a DLV11-J, or similar. . . the 10-pin connectors are all pinned the same.

 

[Uniballer]

My question is if you are going to a DCJ11 CPU (as used in the 11/53, 11/73, 11/8x, 11/9x) why do you feel you need the optional FPJ11 floating point accelerator chip? The J-11 CPU will do floating point in microcode; it just won't be as fast as with the floating point accelerator chip.

As far as speed goes, on most programs an 11/73 will far outperform an 11/53 due to the cache memory. PMI memory would provide an even bigger improvement. AFAIK the 11/93 had no cache memory but the on-board RAM all ran at the speed of the CPU.

I did successfully overclock an 11/83 to 22.1184 MHz many years ago, but I can't really recommend doing that now.

 

[TiggerLAS]

Some of the newer versions of RSTS/E, as well as some Unix variations
will REQUIRE a HARDWARE floating point processor. I don't know about Unix, but RSTS/E
will flat out say "RSTS/E requires a floating point", or something similar, and refuse to boot.
It will do the same thing, if you don't have a line-time clock.

If your plan is only to run RT11, then I wouldn't worry about a hardware floating point unit.

 

[Uniballer]

Some of the newer versions of RSTS/E, as well as some Unix variations
will REQUIRE a HARDWARE floating point processor.

Any DCJ11 CPU (11/53, 11/73, 11/8x, 11/9x) will meet these requirements without an additional floating point accelerator. The floating point instructions and registers are implemented in microcode in the base CPU (see section 1.9 and chapter 7 of EK-DCJ11-UG). The FPJ11 was only to provide additional performance for applications that did a lot of floating point operations (see this nice explanation).

Also, the second page of 2.11bsd_setup.pdf says quite clearly, "KDJ-11 based systems have builtin floating point so the simulator can not be tested." I couldn't find an equivalent statement in the RSTS/E SPD or release notes (although they do say that all the DCJ11 systems are supported, including the 11/53 which does not support the FPJ11).

 

[smp]

After all of my hand wringing, it looks to me like the large quad size boards will be a bit expensive for me. But, thanks to all of your patience and advice, I am deciding that I might as well re-use as much of my current system as I can, and try to upgrade the processor.

I find this eBay auction:

http://www.ebay.com/itm/181618178441?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT

I know that I may have been advised along the way that this processor may not be the "best" way to go, but it allows me to upgrade at a reasonable price, and keep all the other boards that I currently have still working together. I can proceed with an upgrade of the backplane and the memory, later. Perhaps I might be able to get my quad SIO board to run with this processor, too. And, I don't lose my FPU because this processor emulates the FPU in microcode, right?

Please let me know what you think.

Thanks!
smp

 

[Uniballer]

I say, "Buy what you like." If you want the KDJ11-A then get it. If you would actually prefer the KDJ11-Bx then maybe it would pay to wait for one at a lower price. Nobody really knows if or when that will happen,

 

[Qbus]

Been reading your thread with great interest, may end up bidding on that one M8189 that Bill has listed, too bad it don’t have the serial cable with it. The card would look good stuffed in the frame but don’t see that it gives any advantage over the stock M8186 other than allowing you to get rid of a couple other cards. I think my thing is that when you sit down to run a vintage system like a PDP-11 or 8 it’s a given that it will be an old archaic operating system with a limited amount of memory and registers and that’s the fun of learning it and working in that environment. Building up to a more powerful operating system starts to become something like putting a saddle on a cow; you can do it but why bother? If you want a system that’s got a GUI or IP capabilities why not just use a modern micro? But that’s just my opinion and keeps in mind that I am content to just poke around in RT-11 and copy and edit files and run my Basic compiler and build up stupid Basic games. What was the end result that you were looking for in the first place?

 

[smp]

I say, "Buy what you like." If you want the KDJ11-A then get it. If you would actually prefer the KDJ11-Bx then maybe it would pay to wait for one at a lower price. Nobody really knows if or when that will happen,

Thanks very much for your thoughts. I appreciate hearing from you, and I agree, who knows when (or if) a better price might come along.

smp

 

[smp]

Been reading your thread with great interest...

Thanks. I appreciate your interest, and also your thoughts.

I think my thing is that when you sit down to run a vintage system like a PDP-11 or 8 it’s a given that it will be an old archaic operating system with a limited amount of memory and registers and that’s the fun of learning it and working in that environment.

I feel much the same. I got my degree many, many years ago, and I can understand the old systems, while I lost my grasp a long time ago on the new processors and software development environments.

I am content to just poke around in RT-11 and copy and edit files and run my Basic compiler and build up stupid Basic games.

Me too! I am using RT-11-SJ right now on my PDP-11/23.

What was the end result that you were looking for in the first place?

That's a very good question. Originally, with my small 9 row backplane, I was looking for a way to reduce the number of boards in my system, and I was still thinking about staying the system as a PDP-11/23+ so it would still be a proper period correct system. Now, it certainly looks like I've gotten wrapped up in procuring a faster (more powerful?) processor. Thanks for asking. I guess I really have to think about what I really want to accomplish here.

smp

 

[smp]

The M8192 KDJ11-A does not have onboard firmware but I don't think you can install appropriate firmware on an M8012 BDV11 from reading uNOTE #003 and uNOTE #004:

http://www.bitsavers.org/pdf/dec/qbus/oemMicronotes.pdf

You should still be able to use the Emulex UC07 onboard firmware to boot from that controller.

I'm sorry, but I don't fully understand this. Does this mean that if I install an M8192 KDJ11-A, I would have to remove the M8012? Would the KDJ11-A start up into ODT like my M8186, or would taking out the M8012 take that away? I'm confused...

smp

 

[wa2flq]

I'm sorry, but I don't fully understand this. Does this mean that if I install an M8192 KDJ11-A, I would have to remove the M8012? Would the KDJ11-A start up into ODT like my M8186, or would taking out the M8012 take that away? I'm confused...

smp

The KDJ11-A can be configured to drop into ODT when powered up. You can then toggle in a bootstrap for whatever you need manually. See EK-KDJ1A-CG-001 for the configuration details. I think you need to disable the internal LTC (BVNT), if you have the M8012 installed. Otherwise time may pass faster for your programs.

In addition to the pointer gslick gave for uNotes #003 & #004, the other uNotes at full of useful information about Q-Bus devices you are considering (eg. KDJ11-A vs KD11J-B, FPJ11 compatibility etc..) See http://decvax.50megs.com/doc/uNotes/

 

[smp]

The KDJ11-A can be configured to drop into ODT when powered up. You can then toggle in a bootstrap for whatever you need manually. See EK-KDJ1A-CG-001 for the configuration details. I think you need to disable the internal LTC (BVNT), if you have the M8012 installed. Otherwise time may pass faster for your programs.

In addition to the pointer gslick gave for uNotes #003 & #004, the other uNotes at full of useful information about Q-Bus devices you are considering (eg. KDJ11-A vs KD11J-B, FPJ11 compatibility etc..) See http://decvax.50megs.com/doc/uNotes/

Hi wa2flq,

Thank you very much for this information. I have downloaded myself a copy of the KDJ11-A Users Manual, and I am perusing my way through it. Hopefully, between that manual and the Micronotes that have been referenced, I can get the configuration information I would need in order to get the processor to start up properly, and not foul up the line time clock.

I am used to typing in the bits needed to initiate the bootstrap code located on my Emulex SCSI interface board in ODT, so if I can achieve the same for a different processor, that will be fine for me.

Thanks very much again,
smp

 

[Qbus]

You going to bid on that M8189 that Toober is selling? I stopped at $23.00 being I don’t need it for anything because I like lots of cards but it would allow you to remove the communications card and the bootstrap terminator. Too bad it not got the serial cables with it but see that there is another sale for just that but its $65

 

[smp]

You going to bid on that M8189 that Toober is selling?

No, I don't think so. Now that I've gotten myself totally confused, and especially after thinking about and answering all your questions, I think I'll stick with my good, working, period correct PDP-11/23 system, and try learning more about how it all works before I move on to attempt any modifications or "upgrades."

Many thanks to all of you who have answered my questions and offered your thoughts. This is a great place!

smp

 

[TiggerLAS]

I must apologize for the (Hardware) floating point comments that I made earlier.

The QED-93 has absolutely no floating point hardware, or software emulation.
*It* will not be compatible with the afore-mentioned operating systems.

The KDF/KDJ series processor have software floating point, with optional hardware floating point.
Therefore, they should be supported by all of the various DEC operating systems,
with or without the hardware floating point.

I think that I am just so accustomed to having the hardware floating points,
that I confused the two.

I still think that the quad boards are by far more desirable, due to the on-board bootstrap,
and serial ports. Definitely preferred over using a quad-and-a-half, by using a separate
comm board, and modding a BDV11.

 

[Uniballer]

Please stop spreading this misinformation.

The KDF/KDJ series processor have software floating point, with optional hardware floating point.

Forget software floating point. It is not a universally workable solution.

The KDF11 family can be had without hardware floating point, with hardware (microcode) floating point (KEF11-AA) that uses the data paths in the base CPU and KTF11 MMU, and there is also a floating point accelerator option on a separate board, the FPF11, for greater floating point performance.

The KDJ11 CPU family always has hardware (microcode) floating point, but some boards can also use a floating point accelerator coprocessor chip, the FPJ11, for greater floating point performance.

Can we please stop with this now?

 

[TiggerLAS]

Thank you for the clarification -- It is much appreciated.

Perhaps on future postings, you could word your responses a little less tersely,
and with a little less perceived impatience? Or possibly in a private message.

We are all here to learn, and even the most experienced hardware gurus
are prone to providing dis-information from time to time.

Let's keep things civil.

Thanks!

 

[smp]

I know that I probably drive folks here crazy with my simpleton questions.

I probably challenge you folks to come up with explanations that get to my level of understanding, so I probably cause some of the mis-steps simply by someone attempting to be more clear for me.

I greatly appreciate all your attempts to answer my questions. This community has been incredibly supportive to me across my many endeavors, but especially here, as my DEC equipment is the most complex (for me), and you folks have answered my calls for help many, many times.

Thanks very much, once again, for all your attention and effort on my behalf.

smp

 

[smp]

The first M8189 includes the KEF11-AA microcode option, the second one doesn't. You could buy one of these for $15 (or maybe lower offer accepted) to add it if you wanted:
http://www.ebay.com/itm/390174518063

I decided to make an offer to purchase the FPU, and it was accepted.
Now, I'll see what plugging an FPU onto my KDF11-AA will do for me.
If nothing else, there will be the satisfaction of seeing it come up when I do a "SHOW ALL" command.
I'll probably get some more experience with my TU-58 emulator and some diagnostics, too.

smp


smp