QBone in an H11A, amongst other things.

29 views
Skip to first unread message

Lee Adamson

unread,
Aug 2, 2022, 5:58:20 PMAug 2
to UniBone
Good evening gentlemen.

I'm in the process of resuscitating a Heathkit H11A, for which the QBone has been invaluable so far.  If any of you are interested in my mistakes and head-scratching, it's documented here https://odysee.com/@Old.Computer.Fun:f and here https://forum.vcfed.org/index.php?threads/heathkit-h11a-getter-working-thread.1234051/ .

I mostly just wanted to introduce myself.  Although I am having a few odd problems, but I think they are more related to the rather non-standard Heathkit qbus cards (they are using LS240s for bus drivers, among other things).  The CPUs (both an 11/2 and an 11/73) hang when trying to boot anything when I have the Heathkit SRAM installed (despite m tr showing all 12kW good), but it boots fine with other RAM cards (or emulated RAM).  Additionally, paper tape BASIC spams "READY" infinitely and wont accept input after it boots.  Any of you out there with H11s encounter any of this?

Anyway, nice to meet all of you.  I suspect I'll be back with plenty of dumb questions as I muddle my way through this.  ;D

Mark Matlock

unread,
Aug 2, 2022, 7:18:59 PMAug 2
to Lee Adamson, UniBone
Lee,
Welcome to the group. There is a thread in this forum around Nov. 2021 that discussed getting the QBone working with a H11A. The person working to get it going was Eric Moore. I don’t remember the details but the discussion chain may provide some hints.

Best,
Mark
> --
> You received this message because you are subscribed to the Google Groups "UniBone" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to unibone+u...@googlegroups.com.
> To view this discussion on the web visit https://groups.google.com/d/msgid/unibone/4f01fb28-5d8e-4415-bfd5-f9ddc79d8cc2n%40googlegroups.com.

Steven Hirsch

unread,
Aug 2, 2022, 8:37:16 PMAug 2
to Mark Matlock, Lee Adamson, UniBone
On Tue, 2 Aug 2022, Mark Matlock wrote:

> Lee,

> Welcome to the group. There is a thread in this forum around Nov.
> 2021 that discussed getting the QBone working with a H11A. The person
> working to get it going was Eric Moore. I don’t remember the details but
> the discussion chain may provide some hints.

Hi, Lee.

If it helps, I have QBone working on my H11 (2-switch version).

Steve



>
> Best,
> Mark
>
>> On Aug 2, 2022, at 4:58 PM, Lee Adamson <l...@ocfco.net> wrote:
>>
>> Good evening gentlemen.
>>
>> I'm in the process of resuscitating a Heathkit H11A, for which the QBone has been invaluable so far. If any of you are interested in my mistakes and head-scratching, it's documented here https://odysee.com/@Old.Computer.Fun:f and here https://forum.vcfed.org/index.php?threads/heathkit-h11a-getter-working-thread.1234051/ .
>>
>> I mostly just wanted to introduce myself. Although I am having a few odd problems, but I think they are more related to the rather non-standard Heathkit qbus cards (they are using LS240s for bus drivers, among other things). The CPUs (both an 11/2 and an 11/73) hang when trying to boot anything when I have the Heathkit SRAM installed (despite m tr showing all 12kW good), but it boots fine with other RAM cards (or emulated RAM). Additionally, paper tape BASIC spams "READY" infinitely and wont accept input after it boots. Any of you out there with H11s encounter any of this?
>>
>> Anyway, nice to meet all of you. I suspect I'll be back with plenty of dumb questions as I muddle my way through this. ;D
>>
>> --
>> You received this message because you are subscribed to the Google Groups "UniBone" group.
>> To unsubscribe from this group and stop receiving emails from it, send an email to unibone+u...@googlegroups.com.
>> To view this discussion on the web visit https://groups.google.com/d/msgid/unibone/4f01fb28-5d8e-4415-bfd5-f9ddc79d8cc2n%40googlegroups.com.
>
> --
> You received this message because you are subscribed to the Google Groups "UniBone" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to unibone+u...@googlegroups.com.
> To view this discussion on the web visit https://groups.google.com/d/msgid/unibone/AB6E8240-7725-48C1-AE0B-B913022822C2%40MatlockFamily.com.
>

--

Joseph Travis

unread,
Aug 2, 2022, 8:38:42 PMAug 2
to Mark Matlock, Lee Adamson, UniBone
Lee,

I look forward to hearing about your progress.  I recently acquired an H11 / H27 system in pretty rough shape and am also hoping to bring it back to life with the help of a QBone (since I don't have the FDC board for the H27).

Mark,

Thanks for the tip, I'll have to search it out.  I found one instance of someone starting to install a QBone into an H11 but, never saw the end result or if it was working.  I have a strong desire to get mine going and am looking forward to using it.

Regards,
Joe Travis n6ypc


Lee Adamson

unread,
Aug 2, 2022, 8:54:02 PMAug 2
to UniBone
Thanks for the kind welcome, everyone!

Steve, if you have time sometime, would you mind trying to boot the attached paper tape image and let me know your results?  It's the BASIC system I mentioned earlier.  I'm starting to suspect that the Heathkit serial card is doing something that causes it to wig out, as I've tried it with all standard DEC cards other than serial (the Heathkit serial card is the only serial card in the horde that I've gotten working so far, although I do have an apparently nonfunctional M7940 that I need to look into).  Although I admit to having all of the hardware flow control lines bodged back to each other for quick & dirty 2-wire serial testing purposes at the moment, so perhaps that's causing it........

(I'm testing everything in an extra DEC backplane with an ATX power supply, so as to not risk the H11 PSU if something decides to release the magic smoke.)

DEC-11-AJPB-PB.ptap
20220802_205008.jpg

Steven Hirsch

unread,
Aug 2, 2022, 9:25:44 PMAug 2
to Joseph Travis, UniBone
On Tue, 2 Aug 2022, Joseph Travis wrote:

> Lee,

> I look forward to hearing about your progress.  I recently acquired an
> H11 / H27 system in pretty rough shape and am also hoping to bring it
> back to life with the help of a QBone (since I don't have the FDC board
> for the H27).

>
> Mark,
>
> Thanks for the tip, I'll have to search it out.  I found one instance of
> someone starting to install a QBone into an H11 but, never saw the end
> result or if it was working.  I have a strong desire to get mine going
> and am looking forward to using it.
>
> Regards,
> Joe Travis n6ypc

Hi, Joe.

I have a working H11 with QBone. Joerg had to do a bit of software
fiddling to deal with the KF-11 CPU, but it's been working fine since
then.
> To view this discussion on the web visithttps://groups.google.com/d/msgid/unibone/CAGQDgBD5ZMdHQhuo7cifr6RMFWnGdcdvSER%2BPq5j%2BDpBkt66Cw%40mail.gmail.com
> .
>
>

--

Joseph Travis

unread,
Aug 2, 2022, 11:14:14 PMAug 2
to Steven Hirsch, UniBone
Thank you Steve.

I've still got a little ways to go in bringing this system up.  I just went through the power supply today and am going to check out all the boards individually before I put them together on the backplane.  I've also got to build up some serial cables.  Perhaps I can touch base with you for guidance when I get ready to add the QBone.  In the meantime, do you have any comments / suggestions for Lee and I?  Thanks again!

Regards,
Joe Travis n6ypc



Lee Adamson

unread,
Aug 3, 2022, 1:31:21 AMAug 3
to UniBone
The 24-pin molex connectors to mate with the serial and parallel ports appear to no longer be available.  :(  I suspect what I'll eventually try to do is make some kind of pin-header to DE-9 serial cable and try to print a bracket to mount it in the cutout intended for the big molex connector.  I shall do the same for my DELQA and a DA-15 in another molex cutout.

When you make your serial cable, be sure that you look at the pinout of the pin header on the *schematic*.  The pinout in the table in the manual is for the external molex connector, and the ordering is different than the pin header.

When I acquired my unit, the power supply wasn't working, but it turned out to be a bad diode.  Easy fix fortunately.  The Heathkit troubleshooting manuals are really good.

Glenn Roberts

unread,
Aug 3, 2022, 5:49:18 AMAug 3
to Lee Adamson, UniBone
Arcadepartsandrepair is a good source for old Molex style connectors. Do these look right?:

https://www.arcadepartsandrepair.com/store/connectors-sockets-pins/100-kk-molex/24-pin-100-molex-kk-series-connector-housing/

Sent from my iPad

On Aug 3, 2022, at 1:31 AM, Lee Adamson <l...@ocfco.net> wrote:

The 24-pin molex connectors to mate with the serial and parallel ports appear to no longer be available.  :(  I suspect what I'll eventually try to do is make some kind of pin-header to DE-9 serial cable and try to print a bracket to mount it in the cutout intended for the big molex connector.  I shall do the same for my DELQA and a DA-15 in another molex cutout.

pbi...@gmail.com

unread,
Aug 3, 2022, 5:55:08 AMAug 3
to UniBone

glenn.f...@gmail.com

unread,
Aug 3, 2022, 6:48:49 AMAug 3
to pbi...@gmail.com, UniBone

Yes but the problem is the ones with high position counts (e.g. 24) are usually non-stock items, e.g. Mouser seems to stock at most 18-pin versions of the Molex style 2695 or 7880 housings.  Of course you could use two twelve position connectors…

 

The Heathkit H8 uses two 25-count housings to connect the front panel to the bus connectors.  The only in-stock source I’ve found for those is https://www.arcadepartsandrepair.com/

 

If someone knows of other sources it would be useful to know, but please post the exact part number and verify that they’re in stock…

 

Thanks.

 

  • Glenn

pbi...@gmail.com

unread,
Aug 3, 2022, 7:02:03 AMAug 3
to UniBone
Well, sure.  But these are ribbon-cable connections so just use two shorter connectors end-to-end; the ribbon will keep them correctly aligned in the intended end-order.  Or if loose-wiring, mark them distinctly (ideally adjacent on both related surfaces/connectors) and then pay a little attention when connecting :->.  In some circumstances polarization pins might be helpful (but not this time).  I'm thankful that there is *any* reasonable solution when it comes to "legacy" connectors.  Perfection is the enemy of success ...

Joseph Travis

unread,
Aug 3, 2022, 5:37:31 PMAug 3
to pbi...@gmail.com, UniBone
The Molex connector used on the H11-5 Serial I/O and on the H11-2 Parallel I/O boards are single row 25 pin (same as those used on the H8 front panel).  The rectangular Molex connector that is on the back of the H11 chassis is (4X6) 24 pin.   I haven't verified it but I believe the H11-2 and H11-5 used the same cables between the boards and the chassis connectors.

The use of ribbon cable is not required, it was convenient.  Heath used it as it was commonly available and easier for the builder to identify a color rather than counting which wire to place where.  All of the "extra" wires used in the serial interface were to allow for different types of connections (i.e. RS-232 vs. TTL vs, 20mA Current Loop).

Regards,
Joe Travis n6ypc


--
You received this message because you are subscribed to the Google Groups "UniBone" group.
To unsubscribe from this group and stop receiving emails from it, send an email to unibone+u...@googlegroups.com.

Steven Hirsch

unread,
Aug 3, 2022, 7:07:31 PMAug 3
to Lee Adamson, UniBone
On Tue, 2 Aug 2022, Lee Adamson wrote:

> Thanks for the kind welcome, everyone!

> Steve, if you have time sometime, would you mind trying to boot the
> attached paper tape image and let me know your results? 

Sure, if I can blow the dust off from my brain cells long enough to
remember how to do this. I think I have a console program on the windows
laptop that talks to the LSI-11 monitor (ODT) and deposits tap files over
serial. I assume that's what you're trying to do?

Should be able to setup for this within the week - need clear horizontal
space first and that's always a challenge in my shop.

> It's the BASIC system I mentioned earlier.  I'm starting to suspect that
> the Heathkit serial card is doing something that causes it to wig out,
> as I've tried it with all standard DEC cards other than serial (the
> Heathkit serial card is the only serial card in the horde that I've
> gotten working so far, although I do have an apparently nonfunctional
> M7940 that I need to look into).  Although I admit to having all of the
> hardware flow control lines bodged back to each other for quick & dirty
> 2-wire serial testing purposes at the moment, so perhaps that's causing
> it........

None of my Heath branded serial cards work, but I have one DEC 4-port card
that cooperates. I don't believe flow control is used, but it's been over
a year since I last played with it.
> https://groups.google.com/d/msgid/unibone/80782c82-5ae6-4fb0-b8a2-a9072c47aa3dn%40googlegroups.com.
>
>

--

Lee Adamson

unread,
Aug 3, 2022, 8:58:06 PMAug 3
to UniBone
I was meaning something to mate with the 4x6 square connector that mounts in the rear of the enclosure.  My thought was to make a short cable going from the square molex connector to a DB-25 or DE-9 male, rather than trying to hack up something to mount a DE-9 in the big square hole.

I mean, I could just let a cable hang out the back of the machine, but I am being OCD about neatness, heh.

20220803_205237.jpg

Lee Adamson

unread,
Aug 3, 2022, 8:59:40 PMAug 3
to UniBone
I've been loading it via the qbone with "m lp" and then starting it from ODT.
Reply all
Reply to author
Forward
0 new messages