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View Full Version : RK-05J's worth much?



NeXT
November 18th, 2009, 11:49 AM
I stumbled across two RK-05J DecPack drives at the recycling shop and the PDP-8 as well as the disk packs are nowhere in sight. I have not powered either up as they are at the bottom of a skid but they look okay from the exterior. The things are huge and I'm tempted to take them but is it worth it or should I hold my luck out for another?

tradde
November 18th, 2009, 12:12 PM
I stumbled across two RK-05J DecPack drives at the recycling shop and the PDP-8 as well as the disk packs are nowhere in sight. I have not powered either up as they are at the bottom of a skid but they look okay from the exterior. The things are huge and I'm tempted to take them but is it worth it or should I hold my luck out for another?

If they look decent I would grab them. I'd not say they were worth alot, but certainly worth
something. I guess they are getting harder to find like everything else. The problem you
will run into is finding packs for them. You will most likely find the foam seal deteriorating
like all other DEC foam does. They are fairly easy to work on and repair. Oh, find the
cable to connect them to a pdp-8 will be a chore also. I guess it depends on what the
place wants for them and how much you are willing to pay.

NeXT
November 18th, 2009, 12:55 PM
They are free. :D

The thing is I don't see myself going back into town again today so the best I can do is cross my fingers and hope it's there tomorrow still, otherwise it will be sitting over at the school district office, waiting to be processed at which point things get hard to negotiate.

nige the hippy
November 18th, 2009, 02:45 PM
"don't it always seem to be, that you don't know what you got 'till it's gone"

Grab them!, Your side of the pond is 10 years behind us in junk, quite simply because of storage space. They won't be there again, gone forever.....
and we'd pay $200+ apiece for the same thing.

NeXT
November 18th, 2009, 04:21 PM
Okay, so a few hours....and a $25 parking ticket later...the two RK-05's are in my shed.
http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/P9193095.jpg

On the outside they look okay and as warned, all the foam has crumbled inside the case but then I came to two very concerning issues:

1: Where is the Interface flip chip?
http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/P9193093.jpg

2: WHERE THE HELL IS THE HEAD ASSEMBLY?!
http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/P9193094.jpg

It's *GONE*.
Someone took much care to unscrew terminals and unplug cables and remove the head assemblies from both units. I had a bit of hope of restoring the systems sans the interface but without the head assembly there is no point at all.
Great, now unless I find a source for two replacement head units I'm sitting on top of two lumps of scrap metal.

Lou - N2MIY
November 18th, 2009, 04:39 PM
Well,

I still think they are worth $25. Even if I did notice that the heads were gone, I still would have been happy for $25. Everything that is there looks really good. Hang on to these as parts units!

Lou

tradde
November 18th, 2009, 05:09 PM
I have several used RK05s that are only good for spare parts. I believe I would have
several head units. I might not be able to guarantee the condition of them though.
I wonder why someone would just take those parts.

NeXT
November 18th, 2009, 05:28 PM
I assume that they were removed to serve as spares for the missing drive (notice how the drives are marked as disk 2 and 3 with 1 not being present).
It would be cool to get the head assemblies and get the thing into some sort of usable state again but I'll first see if anything happens once I power them up. Hell knows how long these were sitting in storage or in a rack and I hear these PSUs like to go boom after a while.

EDIT: Actually, if I can get the thing to power up no problem I'll be interested in those head assemblies so don't toss them any time soon.

pontus
November 19th, 2009, 12:17 AM
I'm glad you picked them up. They will probably annoy you for taking a lot of space, but if/when you find that PDP-8/e you will be glad you got them. Finding a complete PDP-8 system is not something you do very easily, it is more likely that you will build it up over time.

nige the hippy
November 19th, 2009, 01:22 AM
Good man! but what a shame about the head units. It might be worth a call into the building in case they don't know they've still got them. They could possibly have been removed years ago, but the drives thrown out now because they were taking up space. Ask the janitor if there are any old boxes with loads of switches on the front lying around too!

NeXT
November 19th, 2009, 06:58 AM
Good man! but what a shame about the head units. It might be worth a call into the building in case they don't know they've still got them. They could possibly have been removed years ago, but the drives thrown out now because they were taking up space. Ask the janitor if there are any old boxes with loads of switches on the front lying around too!

I'm doubtful.
Some of the hardware that comes in actually comes from other palces in town and no records are kept. As far as I know they could of come from anywhere.

NeXT
November 19th, 2009, 09:54 AM
Both powered up no problem afte a little creativity...
http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/RK05J/P9203113.jpg

I got no smoke, no extra nasty noises (the spindle needs to be oiled I think) and no explosions after leting both run for ten minutes each.
I did panic for a second when I was not getting any power light (inclusing the Fault lamp thankfully) but found out that I'm missing all but three of the bulbs in both.
http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/RK05J/P9203116.jpg
Moving the bulbs around found that currently the Power lamp is lit and nothing else so that's good.
Anyways, I'll take your offer if you still got two head units. I'm assuming all the missing parts from that general area in both units (the heads and their mechanical parts which should be here (http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/RK05J/P9203104.jpg))
Oh, another thing too.
As mentioned, both systems have a nearly complete set of Flip Chips (http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/RK05J/P9203097.jpg) sans one board which I assume was nothing but a blank PCB with ribbon cable headers on it. Are these chips the actual disk controller or should there be another set of flip chips in the PDP to control the drive and this si the I/O that makes the drive actually do something?
Also, regarding fridge logic ( ;) ), I don't know if this is because I'm missing parts but While I can get teh spindle motor to spin up, I con't figure out how to spin it down again (I switch to LOAD and open the door and it's still spinning away) unless I unplug the system. I assume there is a switch in the head mechanism that tells the motor to spin down when the heads are retracted, right?

tradde
November 19th, 2009, 04:48 PM
Both powered up no problem afte a little creativity...
http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/RK05J/P9203113.jpg

I got no smoke, no extra nasty noises (the spindle needs to be oiled I think) and no explosions after leting both run for ten minutes each.
I did panic for a second when I was not getting any power light (inclusing the Fault lamp thankfully) but found out that I'm missing all but three of the bulbs in both.
http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/RK05J/P9203116.jpg
Moving the bulbs around found that currently the Power lamp is lit and nothing else so that's good.
Anyways, I'll take your offer if you still got two head units. I'm assuming all the missing parts from that general area in both units (the heads and their mechanical parts which should be here (http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/RK05J/P9203104.jpg))
Oh, another thing too.
As mentioned, both systems have a nearly complete set of Flip Chips (http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/RK05J/P9203097.jpg) sans one board which I assume was nothing but a blank PCB with ribbon cable headers on it. Are these chips the actual disk controller or should there be another set of flip chips in the PDP to control the drive and this si the I/O that makes the drive actually do something?
Also, regarding fridge logic ( ;) ), I don't know if this is because I'm missing parts but While I can get teh spindle motor to spin up, I con't figure out how to spin it down again (I switch to LOAD and open the door and it's still spinning away) unless I unplug the system. I assume there is a switch in the head mechanism that tells the motor to spin down when the heads are retracted, right?

The door should be locked until the disk spins down. Does the spindle only start to turn
when you push in the load switch? If it does, clicking it the other way should turn it off
and let it spin down. Only after it's stopped is the front door supposed to be able to
open. Maybe you are missing a sensor? Or because you have no disk mounted? I am
not sure if it should even spin up with no disk in. Maybe you mean the lower spindle
only turns since that's powered via a belt?

I will check the head units in the spares I have. As to bulbs you are going to find they
are hard to come by also. The missing flip chip in the back I believe is just a connector.
The controller is a 3 board (DEC) set that is in the 8.

pontus
November 19th, 2009, 11:33 PM
This guy has put LED in his RK05

http://pdp8.hachti.de/

Here is a clip of his LAB-8/e booting from RK05 (with leds)

http://www.youtube.com/watch?v=ByLp9A1nn7U

NeXT
November 20th, 2009, 02:58 AM
Holy crap, he's the owner of the Lab PDP? Wow.
Hmm, I'll have to check to see the voltages the bulbs run off of and hop it's like 12 volts or something nice like that.

NeXT
November 22nd, 2009, 04:53 PM
I'm going to have to go with the advice of a few people and just keep these systems as spares unless I somehow discover out of the blue a more local set of heads and an alignment pack. I have a contact who looks at the same recycling pile I got these from so if anything passes through there he'll give me a shout. Still, I wish I knew who dropped them off...

hachti
February 7th, 2010, 12:22 PM
This guy has put LED in his RK05

http://pdp8.hachti.de/

Indeed, I have. I usually tend to say that it's nicer to have the original incandescent lights. My CPUs are all with incandescent lights. The lab8/e itself has been switched back to incandescent lights.

For RK05 its a bit different:
a) I have bulbs so I can put them into the drives whenever I like.
b) It looks very funny with those high power LEDs. And you can actually see every access. With incandescent lights you won't see the light flashing on very short accesses.
c) As the lamps are just plugged, it's completely harmless (from a conservatory point of vies) to play with LEDs in that place.


Holy crap, he's the owner of the Lab PDP? Wow.

Hm, I was just lucky - even with FPP12 :p
Still looking for a TC08 DECTape controller!!! :cool:


Hmm, I'll have to check to see the voltages the bulbs run off of and hop it's like 12 volts or something nice like that.

The lamps are run by 15V with a 47 Ohm resistor in series!

Kind regards,


Philipp

donutty
February 8th, 2010, 11:56 AM
Nice find and well worth the parking ticket in my opinion! I love happy ending stories like these :)
Nowadays(tm) you can buy LED replacements for old-style bulbs that will last forever, like these: http://uk.rs-online.com/web/search/searchBrowseAction.html?method=retrieveTfg&Ne=4294957561&N=4294953843

Oh and yeah, they run over a wide voltage range (and usually AC and DC) so they are a simple 'drop in' replacement

(I hope the link works)