Dec RK8E controller for RK05 wanted

[Roland Huisman]

After you clean the heads, you can manually load them to make sure that nothing bad happens.

That head cleaning is absolutely necessary But the amount of dust around the
heads is also shocking... Dust stick to the wires, on top of the head assembly etc...

dirt.jpg

The maintenance manual shows some jumpers that you can install to perform some seek tests.

Okay thanks for the info. I have to look into that manual for that.

The FLIR images are very cool.

Yeah I thought also

[Roland Huisman]

I found RK8E testsoftware ( dhrkae.sv ) on an RK05 image which I use with Kyles disk server.
Are these different from the papertape versions? Or are they at least documented?

And I wonder, the RK05 image is modified to work with the disk server.
Would it still be possible to run that RK8E test then?

[anders_bzn]

I guess a bit, but the MAINDEC's doesn't use OS/8 for testing, so it should be fine to run them.

[Roland Huisman]

In the meanwhile Jack Rubin did help me a lot to get GTTY running again on a modern PC.
And Lou helped me a lot with his H803 which I turned into H851s

So my Plessey RK8E clone now has brand new H851 blocks on it:
08 H803 to H851.jpg

Time to test...

I guess a bit, but the MAINDEC's doesn't use OS/8 for testing, so it should be fine to run them.

Well I've tried to test the Plessey controller which was bought incomplete. So it was in unknown state.
I ran dhrkae.sv on the service image within OS8. And immediately I got:

STATUS REGISTER ERROR
PC:0243 GD:2200 ST:2202
DHRKAE FAILED PC:6726 AC:0000 MQ:7777 FL:0001
WAITING

If I pulled out the controller I got a slightly different message.
So it seems to detect the board but it quits almost immediately as well.

To be sure I wanted to toggle in the rimloader, load the binloader and run the
test from a papertape image which I downloaded from Vince his website.

After toggeling in the RIM loader somehow I made an error myself and gave
the start address of 7777 instead of the 7756. Suddenly text like this showed up.

DHRKAE PASS 0202
DHRKAE PASS 0203
DHRKAE PASS 0204

Now that is weird! I haven't loaded any papertape image yet. This was still in core.
Within a few seconds this message showed up in the disk server:

Warning: client asking to overwrite system handler!
Failed to initialize, sending NACK

Probably the code ran into a part of OS8 in core, no idea what happend...

Next try went better... Rim loader, bin loader and loaded dhrka-e.bin
After starting the test the system ran for about four minutes and then:

RK8E DISKLESS PASS COMPLETE

WooHoo! So don't run tests within OS8 disk server... This might fail...

01 Testing in PDP8e.jpg 02 woops.jpg 03 another woops.jpg 04 RK8E DISKLESS PASS COMPLETE.jpg

The postman from China is letting me down a bit. I'm waiting for three weeks now on the M993 PCB's.
At this point I can't get any further... I hope the boards are coming soon...

[m_thompson]

Mine was a lot more difficult to get running. One of the delay lines that was added by DEC as an ECO was ripped off the PCB. Vince gave me a flipchip so that I could remove a delay line and replace mine. With a few broken chips replaced, it is now working OK.

[anders_bzn]

Well done!

[Roland Huisman]

Does anyone have one or more (even crashed) 16 sector RK05 disk packs for sale?
This would be a great help to me.

I have only one 16 sector pack and I don't want to run the disk tests on it because
the disk would be wiped after that. And I would like to preserve the data of course.

Thanks in advance!
Roland

[Roland Huisman]

Finally, the M993 boards (which I call the M993D) arrived Wednesday
together with the bootloader PCB's. The Bootloader took only
about 5 days and the M993D took about 5 weeks... Niels (lives in China)
put them in his suitcase when he went to Belgium to ship it from there.
But he forgot to ship it and it took more time instead of less time...
I can't blame him, the intentions were good

I've put on the few components. One of the two empty resistor places is
to omit the TTL and transistor circuit which is seen on some M993 boards.
The other is to select a different pin which I mentioned earlier in this topic.

12 M993D.jpg

When I want to put it in the RK05 it just would not fit. It was too tight...
I've got an nice H803 from Lou so I could see where it goes wrong.
I had to use a file to just get a very very little bit off of the connector edges.
And I made a V shape at the bottom of the PCB as well. Now it fit's nicely into the H803

13 M993D fits.jpg

I wired it all up. Figuring out how it was meant to be connected. Hope I'm right

M993D cables.jpg

And finally wired the RK05. So it's ready for the next tests...
I want to get the bootloader project done first because there is only a bit
software to do. And the bootloader can be a great help to service the RK05.

M993D in RK05.jpg

Regards, Roland

[anders_bzn]

Do you have the M930 board in your drive? I have finally brought my drive home, I'm missing both the M993 and the M930 boards...

What did you do about all the foam? Did you replace it our just removed it?

Mine is crispy and it just fells apart.

[Roland Huisman]

Do you have the M930 board in your drive? I have finally brought my drive home, I'm missing both the M993 and the M930 boards...

What did you do about all the foam? Did you replace it our just removed it?

Mine is crispy and it just fells apart.

I've got a M930 from a collector here in the Netherlands but there are some
M930 on Ebay as well... https://www.ebay.nl/itm/200601634187

I've redesigned the M993 which you can see on the pictures. This is one is also in my drive.
(I've got 9 spare boards for several people, but I want to test it before I ship them)

I had to replace all the foam in my drive as you can see here

Regards, Roland