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Heathkit H11A Gett'er Working Thread.

bladamson

Veteran Member
Joined
Nov 11, 2018
Messages
731
Location
Appalachia
Good evening gentlemen.

Within the past month or so, I've become the latest caretaker of a Heathkit H11A and a pile of QBus cards. This is a machine that has been on my bucket list for some time, so I am very excited to be able to service the machine, get it back in operating order, and document as much of it as I can.

To that end, I'm posting some videos about it. There's been a short interruption as I embrace sobriety and clean out and reorganize my workshop, but I am almost to the point of putting up the new workbench at which point the H11 stuff will continue.

If you feel up to the task of sitting through my rambling, this specific content can be found on the following playlist on my Odysee channel: https://odysee.com/$/list/499e7da1db27b44db14312660f741e4afca52b49

I also post to YouTube, but I delay posts there by one week to encourage the use of alt-tech platforms: https://www.youtube.com/playlist?lis...5LTZEM0FteJ27D

I shall update this thread as new content on the subject is produced. Here's what I have so far:

- The Heathkit H11 (PDP-11) | A look at all the qbus cards, and fixing the power supply.
https://odysee.com/@Old.Computer.Fun:f/H11-01:f

- The Heathkit H11 (PDP-11) | SASI, Mounting PDP-11 Filesystems on Linux, and a Qbus Ethernet Card.
https://odysee.com/@Old.Computer.Fun:f/H11-02:0
 

cbscpe

Experienced Member
Joined
Apr 11, 2017
Messages
361
Location
Switzerland
What a nice system. Yes Heathkit and digital in one box this is really awesome. The disk controller most likely talked to a Xebec S1410. I have almost the same controller and have attached a SD2SCSI Version 5.0, I had no success using a SD2SCSI V5.1, with the newest firmware. As the controller emulates emulates an RLV11/12 you need to create some RL02 images and then convert them. Here is some information and a way to create disk-images for the SD2SCSI with 256 sectors (it's actually just splitting the 512bytes sectors of a RL02 disk image into 2 x 512 sectors on the SD-Card with the first 256bytes going to the 1st sector and the second 256bytes going to the 2nd sector) https://www.5volts.ch/posts/plessey/. It's at the end of the web page.
 

bladamson

Veteran Member
Joined
Nov 11, 2018
Messages
731
Location
Appalachia
What a nice system. Yes Heathkit and digital in one box this is really awesome. The disk controller most likely talked to a Xebec S1410. I have almost the same controller and have attached a SD2SCSI Version 5.0, I had no success using a SD2SCSI V5.1, with the newest firmware. As the controller emulates emulates an RLV11/12 you need to create some RL02 images and then convert them. Here is some information and a way to create disk-images for the SD2SCSI with 256 sectors (it's actually just splitting the 512bytes sectors of a RL02 disk image into 2 x 512 sectors on the SD-Card with the first 256bytes going to the 1st sector and the second 256bytes going to the 2nd sector) https://www.5volts.ch/posts/plessey/. It's at the end of the web page.

Ah drat, version 5.1s are all I have! There are some Emulex UC7s on ebay, but the prices are absolutely insane. I guess I'll be emulating drives with the qbone for now then.

Thanks for the info. You've probably saved me a pile of headaches.
 

cbscpe

Experienced Member
Joined
Apr 11, 2017
Messages
361
Location
Switzerland
Don't give up. I did not really investigate the issue for a long time when activating my Plessey controller. Mostly due to the fact, that my V5.0 with the newest firmware immediately worked. I tried the V5.1 several times but perhaps I was just not patient enough. The main reason I did give up fast was the fact that Version 5.0 is still available at https://itead.cc/product/scsi2sd/ for quite a decent price. And as I want to have as many SCSI2SD as I have systems I anyway had to buy another one.

You should try your luck with one of your V5.1 SCSI2SD, perhaps your controller is not as picky as mine. YMMV. Also, I checked the SCSI2SD Wiki and found that the V5.1 and newer got a major firmware upgrade. I definitively will give it a try with my Plessey RLV12 controller when I have time. You could as well contact Michael McMaster perhaps he has some more ideas.

And then there is still your QBone which can emulate RLV12 and MSCP.

Edit: it seems the major update is only for 5.2, but not for 5.0, 5.1 and 5.5 :rolleyes:
 
Last edited:

tradde

Veteran Member
Joined
Apr 30, 2003
Messages
1,262
Location
Katy, Tx
So he could flash the firmware back to 5.0? Or forward to a newer one? I don't remember if this can be done. I have an older SCSI2SD but have not messed with it in some time.
 

bladamson

Veteran Member
Joined
Nov 11, 2018
Messages
731
Location
Appalachia
... Version 5.0 is still available ... And as I want to have as many SCSI2SD as I have systems ...

Hmm yeah, all of my SCSI2SDs are already assigned to machines, so I guess getting a 5.0 if needed wouldn't be that big a deal anyway.

Thanks again, gentlemen.

FWIW, I ought to have my new bench built by the end of the week, so hopefully I can dive back into this thing. I am really anxious to get it going.
 

cbscpe

Experienced Member
Joined
Apr 11, 2017
Messages
361
Location
Switzerland
So he could flash the firmware back to 5.0? Or forward to a newer one? I don't remember if this can be done. I have an older SCSI2SD but have not messed with it in some time.
The figures refer to the hardware revisions. Many revisions require different firmware which is not compatible with the other hardware revisions.
 
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