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DEC Robin - where to start?

AdamAnt316

AdamAnt316

Experienced Member
Joined
May 23, 2016
Messages
230
Location
Massachusetts
Hello everyone. I have been building up a VT-180 setup piece-by-piece. Last year at a hamfest, I bought a pair of VT-100 terminals (both of which have apparently been upgraded to VT-125 status, though the badges on the front don't reflect this) with keyboards from one seller, and some of the innards (processor board, analog board/s, card cage) of a VT-180 'Robin' from another seller. Just this past weekend, I found a DEC RX-180AB dual floppy drive at another flea market; it didn't come with any cables or disks, but seems to be intact.

My question is, where to go from here? I've wanted some DEC hardware for awhile, but it tends to be rather expensive, and seems to be oddly thin on the ground considering where I live (I regularly drive past one of the old DEC office buildings), so this is my first experience with their gear. First, is there a good source for the software? In the meantime, is there a way to test and see whether or not everything is working without said software? I was told that at least of the VT-100/125s works, but have yet to test the disk drive. What sort of cable do I need to connect the drive to the Robin board? Finally, is it absolutely necessary to have four drives with a VT-180? Most of the pictures I've seen of the RX-180 show two separate units (one AB, one AD). Anyway, thanks in advance!
-Adam
 
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AdamAnt316 said:
My question is, where to go from here? ... First, is there a good source for the software? ... Also, is it absolutely necessary to have four drives with a VT-180?
-Adam
Click to expand...

Where you go from here (and where you should have started) is reading the manuals on Bitsavers. I know, because I got my Robin working by myself from what is available on Bitsavers.

The manuals and print sets are on Bitsavers (http://www.bitsavers.org/pdf/dec/terminal/vt180/). So are disk images of plenty of software (http://www.bitsavers.org/pdf/dec/terminal/vt180/dskimage/). We have Will K. (of TU58.exe fame) to thank for archiving these disks. I turned the images back into real 5-1/4" floppies using Dave Dunfield's Imagedisk on a PC with a 360k floppy drive. The VT100 basic video board in my Robin was broke. I fixed it. See here: http://www.vcfed.org/forum/album.php?albumid=56&attachmentid=2421 . This was the first VT100 I ever repaired. From what I learned I ended up fixing half a dozen others.

You do not need four floppy drives. Two is sufficient. I didn't even have a real RX180, I built my own clone. See this album: http://www.vcfed.org/forum/album.php?albumid=375 .

Lou
 
I found the cables for the disk drives at

http://seadec.com/

They are:

BC26K (DB25 to DC37) Machine to 1st disk cabinet

BC26Z (DB25 to DB25) First disk cabinet to second disk cabinet

I could or should have made my own, but I didn't have the 37 pin header, and these were the correct DEC part :) I think I paid about $30.

For what it's worth, I had to replace the power switch on my VT-180. This works as a replacement:

Home Depot:

GSW-14
Store SKU: 540366
Catalog/Internet: 100149490

Menards:

Menards® SKU: 3638699
 
Thanks for the replies! :D I have downloaded the manuals, but have yet to delve into them. I'll have to put together a 'tweener' machine to make these disks, and figure out the software used to make them. I made CP/M disks for my Commodore 128 many years ago, but I'm guessing the procedure involved for these VT180 disks is rather different, and the 'tweener' machine I used for those is currently down for the count.

ScutBoy, thanks for that link! The website's a bit old, but should be useful if I can figure out the part numbers for things I need, and if they have them. Unfortunately, it doesn't appear that they have the "Shield, rear (module access cover)", part #74-26146, along with the "Cable access cover (wort cover)", part #74-26145, unless I was searching wrong. Both of my VT100s have the 'module access cover' for the VT125 board, which probably won't be of much use with the VT180 board and its connectors. I did get a card cage of some sort with the VT180 board, so there's that. :)
-Adam
 
I guess this would be my "tweener machine" : http://www.vcfed.org/forum/album.php?albumid=2&attachmentid=2381

You absolutely want to use Imagedisk (http://www.classiccmp.org/dunfield/img/index.htm). Dave provides the utilities you need to convert the image format of the disks on Bitsavers to his format.

You can't have the VT125 board and Robin in at the same time. This you must realize by now. Honestly, I found the VT125 board only a novelty. I went to all the trouble to convert a VT100, and then never found any cool applications that needed a ReGIS terminal. Perhaps I should have looked harder.

Lou
 
Lou - N2MIY said:
I guess this would be my "tweener machine" : http://www.vcfed.org/forum/album.php?albumid=2&attachmentid=2381
Click to expand...
Impressive! :shocked: :bow2: The 'tweener' I used to make the aforementioned Commodore 128 CP/M disks was, appropriately, a Commodore PC40-III (aka "Special Edition 286") which had both 3.5" and 5.25" drives (both HD) from the factory. Unfortunately, it lost its BIOS settings when the battery inside the Dallas Semiconductor RTC chip bit the dust, and manually punching in the HD specs isn't enough for it, so I'll have to hope that the modern DS12887 will work with it.

My other options are an unknown XT clone which is similarly equipped with drives, albeit in DD form, and an Amiga 2000 which has an A8088XT bridgeboard installed. I probably don't have to worry about the XT clone having lost BIOS settings, but it hasn't been powered up in 15 or so years, so age might've caught up with it in other ways. As for the A2000, it's as of yet untested, and I'm not entirely sure whether or not said bridgeboard would be able to use either of the A2000's two built-in 3.5" floppy drives while in PC mode, or if I'd have to find an A1011 or similar external drive.

Lou - N2MIY said:
You absolutely want to use Imagedisk (http://www.classiccmp.org/dunfield/img/index.htm). Dave provides the utilities you need to convert the image format of the disks on Bitsavers to his format.
Click to expand...

Again, good to know, thanks.

Lou - N2MIY said:
You can't have the VT125 board and Robin in at the same time. This you must realize by now. Honestly, I found the VT125 board only a novelty. I went to all the trouble to convert a VT100, and then never found any cool applications that needed a ReGIS terminal. Perhaps I should have looked harder.

Lou
Click to expand...
Yeah, I figured one of them would have to be 'neutered' in order to facilitate the VT180 conversion. Oddly, the VT180 Technical Manual seems to imply that the VT125 "cannot use VT18X option", as only the VT132 has an asterisk next to it saying that it can be converted if returned to VT100 configuration first; yet my 'VT125s' seem to be VT100s which were converted to VT125 status, so I dunno how this would disqualify them from reconversion to VT18x status if the add-on board were removed. :confused: I have yet to do much with terminals in general; the only other terminal I have is an old Lear-Siegler ADM-3A video terminal which is in horrible shape, and I've had no reason yet to attempt to restore it to working order.
-Adam
 
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Henk said:
I was / am looking for a BC26K cable, so after reading your post, I emailed seadec.com ... got no response at all :(
From doc on the internet, I made my own cable, see http://www.pdp-11.nl/vt180/vt180-info.html
I would appreciate it if you could check the pin to pin connections of your original BC26K cable.
Thanks,
Henk
Click to expand...
Bummer. Have you tried calling them? A phone number is posted on the website. If my email isn't answered and I can't otherwise get ahold of them, I'm probably going to take an existing DB25-to-DB25 cable, and replace one of the connectors with a DB37. I'd prefer to find an original cable, but any port in a storm, as they say.....
-Adam
 
Hi Adam,
indeed, maybe I should call them. One international phone call might be all it takes ...
I did make my own cable, wire by wire, but I would like to have proof that the cable I made is correct!
How I wired from the DB-25 to the DC-37 is on my website. You can use it, but no guarantees!
The table is not confirmed to be correct !!
I would be perfectly fine with my home-made cable, but I am seeking proof that it is correct.
So, all I need is just one guy owning a BC26K with an Ohm meter and the willingness to take 10 minutes ...
OK, paper and pen/pencil would be handy :)
 
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