Adding top row of F keys to OmniKey/Plus

SteveN

22 Mar 2021, 05:21

Hi Guys,
Does anyone know if it's possible to turn a NorthGate OmniKey/Plus into an Ultra? I imagine the keycaps and switches for the top row of function keys could be had, I'm just not sure if there's anything underneath that the Plus would not have.

I have an outstanding condition Plus that I've used for 20+ years, but it's come time to refurbish it and I'd really like to add the top row of keys whilst I'm at it.

User avatar
XMIT
[ XMIT ]

22 Mar 2021, 05:27

Some boards have a function key strip that covers holes in the case, and spaces in the plate and PCB for more switches. Some don't. Take it apart and see!

User avatar
Polecat

22 Mar 2021, 05:44

The Plus (Gen2 Northgate) should have the spots for the extra switches. But the ROM may be different. The Gen2 Ultra came in at least three versions, with the dipswitch functions and specifically the method of reprogramming the special function (SF) keys being different between the three. I don't know of a way to tell visually if your Plus is compatible with any of the three, but some had a version number (3.xx or 6.xx) printed on the EPROM and I have some notes on those. It may be on the bottom label but that doesn't always match the actual ROM. You could try soldering in one switch in one of the extra positions (with the top case removed) to see if it generates a valid scan code, and if it does then try the three instruction versions to reassign it (Fx, Ctrl-Fx, Shift-Fx, or Alt-Fx). Let me know if you get that far and need the instructions.

SteveN

22 Mar 2021, 11:01

The bottom label has: 051710-89/11. I'm guessing the 89/11 is November 1989 production date.

Whilst I'm building a parts list, does anyone know if the F13-F15 keys can be made functional (or the Omni key for that matter)? In my reading it seems this isn't something folks have had too much luck with without modifications. Will a TMK (?) / Soarers conversion enable these keys to work?

User avatar
Polecat

22 Mar 2021, 16:28

That's a pretty early Gen2, probably a Vendor 222 version. So far I haven't seen a Vendor 222 (or 333) Ultra model. The earliest Ultra on my list is a Vendor 777 model from February 1990 so yours might not have the spots for the extra switches that the later Vendor 777 versions had. A quick look inside the case will tell you that, it's just six screws to remove the lower case.

SteveN

23 Mar 2021, 06:47

Darn. No joy. It looks like there is no room for the top row of F keys. Even if I wanted to hack the metal, there's a big cable in the way.

Omnikey-plus-inside.jpg
Omnikey-plus-inside.jpg (1.59 MiB) Viewed 399 times

So it looks like I'm going to have to source an Ultra-T somewhere, or perhaps something like an IBM Model F 104 or AT keyboard.

User avatar
XMIT
[ XMIT ]

23 Mar 2021, 13:19

Can you please remove the keyboard and PCB assembly and post a photo of the underside of the circuit board?

SteveN

23 Mar 2021, 14:37

I can try. What is it we're trying to determine with that?

User avatar
XMIT
[ XMIT ]

23 Mar 2021, 14:40

We're trying to see if the PCB has accommodations for another row of switches.

To do this, remove the four screws, two on each side, holding the plate in place. Then, rotate the plate up about the top edge of the keyboard, being mindful of the ribbon cable.

It is unlikely that it has accommodations for more switches given the ribbon cable placement. If it does not, you would be looking at substantial modification to add another row, likely more than you are willing to do.

User avatar
Polecat

24 Mar 2021, 01:44

SteveN wrote:
23 Mar 2021, 06:47
Darn. No joy. It looks like there is no room for the top row of F keys. Even if I wanted to hack the metal, there's a big cable in the way.


Omnikey-plus-inside.jpg


So it looks like I'm going to have to source an Ultra-T somewhere, or perhaps something like an IBM Model F 104 or AT keyboard.
Sorry that's an early Gen2 model, and the Ultra hadn't come out yet when that one was built, so no shared plates or PC boards. Gen2 and Gen3 Ultras and Ultra-Ts come up on ebay frequently, just be patient and wait for one in the condition you want for a reasonable price as some are a lot more expensive than others.

SteveN

24 Mar 2021, 14:05

Is there a way to tell the difference between a Gen2 and Gen3 Ultra-T visually? (and does it matter?)

User avatar
Polecat

24 Mar 2021, 16:37

Actually I don't think there was a Gen2 Ultra-T model. Those came out after the Ultras with the extra Plus-style nav keys, and with over 500 Northgates documented I haven't seen a Gen2 Utra-T.

In general the Gen2 Northgates had the dipswitches accessed through a slot on the back edge, while the Gen3 had them under the badge on the top left corner. Gen4 had the hinged door under the badge, but no dipswitches as those were programmable.

Generation matters if you're concerned about the layout, since there were a couple differences. Most obviously on the Ultras was the location of the Esc key, which was in the number row on Gen2, but in the F-key row on Gen3. Also the white SKCM switches changed during the Gen3 period from Pine to Bamboo, and some people prefer one over the other. Also watch the location of the left Ctrl and CapsLock keys if that's important. Both the Gen2 and Gen3 originally came with extra keycaps to swap the left Ctrl and CapsLock keys. But unless you find a NIB example you won't have those extra caps, so be sure to get one with those keys where you want them.

SteveN

25 Mar 2021, 05:03

Thanks, that's helpful. So it looks like this is going to be a waiting game with eBay until the right deal comes along.

The deskthority wiki suggests that:
a good thorough cleaning of the sliders and switch tops, and a shot of compressed air in the bottoms and the switch plates, even the dirtiest of switches can feel like new, so long as the springs or switch plates are not rusted. An ultrasonic cleaner is recommended for cleaning the switch tops and the switch sliders. Ultrasonic cleaning is not recommended or generally necessary for the switch housing bottoms, switch plates, springs, or leaves.
This YouTube tutorial on restoring alps mentions a 'soft clean'; I vacuum the keyboard monthly and that seems to be keeping it in good nick. Just one area with a bit of an annoying intermittent rattle, that seems to have lessened since I took the cover off.

User avatar
Polecat

26 Mar 2021, 05:35

I think you're on the right track with vacuuming and keeping the dust out. I'm no expert on Alps cleaning. I've been using Alps switches for probably thirty years, and I blow the dust out with compressed air once or twice a year. I've never done any disassembly of switches (besides peeking at the internal parts) or ultrasonic cleaning. But that might be necessary if you've spilled food or drink into the keyboard or if it's been stored in a really dusty place. There's a lot of info here on cleaning and lubing Alps switches; it's an ongoing discussion and learning experience.

User avatar
XMIT
[ XMIT ]

26 Mar 2021, 08:37

I think that Wiki page wording was taken from one of my threads. At the time I was unsure what ultrasonic cleaning would do to the thin leaf springs and what not. It's harmless. But doing a full cleaning does require desoldering. The technique described there is great if you don't want to desolder the whole board.

Post Reply

Return to “Workshop”