Harris Smart Terminal, xwhatsit Model F to USB

I came across Sangdrax's excellent work and background info on this GH post: https://geekhack.org/index.php?topic=90...msg2436488 so when I came across the same board for a reasonable price I went for it.

orig_DT.jpg


This one is dated July 27, 1978.
date_small.jpg


Sangdrax did a great job documenting the board - I thought I'd have a go at converting it and add a few more pics too.
I's an interesting capacitive board:

open1_DT.jpg

backplane2_DT.jpg

PCB_back_DT.jpg

front2_DT.jpg

PCB_front_DT.jpg


The rows are wired to pads under soldermask in the PCB and the columns to the copper leafs :

contacts_DT.jpg




Sangdrax figured out the board was 8 row by 16 columns and I thought I'd put a few more pics of the IC connections (labeled with arbitrary numbers and letters):

rows_DT_nums.jpg
Rows


columns_DT_nums.jpg
Columns


Then desoldered the ICs and wired up the xwhatsit:

wired1.jpg


And much to my relief, it worked! Voltage threshold seems good between 150 - 160 and I went ahead at set it at 158 like Sangdrax. Once I was sure everything was good, I went ahead and hooked up the lock lights to three of the onboard LEDs.

lights1.jpg


And retrobrighted the blue keys

retro.jpg


I need to touch up the case but I'm really pleased with this board and am going to be using it a lot.

after1_DT.jpg

caselights2.jpg

caselights3.jpg


Thanks again to Sangdrax for the heads up and tips on this board!
OldIsNew
User avatar

Unread post05 Oct 2017, 05:54

User avatar
X
OldIsNew
 
Posts: 60
Joined: 24 Mar 2017, 18:55
Location: US
Club member: -
 
Definitely take the time to lube the plungers on the board if you get a chance. It makes everything so smooth. The dried gunk on mine sure made it look like it was that way originally too. Best way to do it is press the plunger down and apply to the cross stem underneath instead of trying to work around the springs up top.

It's still my daily board over even my beamspring. Love this thing. I can post my layer layouts too if that would help at all. My favorite is basically the one that makes it like a TKL plus media keys.
Sangdrax

Unread post05 Oct 2017, 06:29

X
Sangdrax
 
Posts: 45
Joined: 05 Jul 2017, 06:50
Location: Acadiana
Main keyboard: Harris 1978 Terminal
Main mouse: Mammoth
Club member: -
 
I can't tell what the color the keycaps are due to the inconsistent lighting. But those sphericals are amazing!
zslane
User avatar

Unread post05 Oct 2017, 18:01

User avatar
X
zslane
 
Posts: 2336
Joined: 22 Jul 2015, 23:54
Location: Los Angeles, California, USA
Main keyboard: RealForce RGB
Main mouse: Basic Microsoft USB mouse
Favorite switch: Topre
Club member: -
 
Sangdrax wrote:Definitely take the time to lube the plungers on the board if you get a chance...
It I can post my layer layouts too if that would help at all.

I lubed the plungers and yes - it does make a nice difference for sure! If you get a chance to post your layer layouts those would be great to take a look at - thanks!
zslane wrote:I can't tell what the color the keycaps are due to the inconsistent lighting. But those sphericals are amazing!

I'd say light blue/teal is best description of color. I've just got a cheapo cell phone camera.
OldIsNew
User avatar

Unread post06 Oct 2017, 06:25

User avatar
X
OldIsNew
 
Posts: 60
Joined: 24 Mar 2017, 18:55
Location: US
Club member: -
 
Yeah, they're definitely teal. A photo in natural light will show it the best.

Oh, and I made the layout thing. I pretty much just use the bottom one all the time unless I need to punch in a bunch of numbers.

Image
Sangdrax

Unread post06 Oct 2017, 08:10

X
Sangdrax
 
Posts: 45
Joined: 05 Jul 2017, 06:50
Location: Acadiana
Main keyboard: Harris 1978 Terminal
Main mouse: Mammoth
Club member: -
 
Dat blue! So beautiful!
zslane
User avatar

Unread post06 Oct 2017, 17:45

User avatar
X
zslane
 
Posts: 2336
Joined: 22 Jul 2015, 23:54
Location: Los Angeles, California, USA
Main keyboard: RealForce RGB
Main mouse: Basic Microsoft USB mouse
Favorite switch: Topre
Club member: -
 
What does it sound like? Can you post a video?
paecific.jr
User avatar

Unread post06 Oct 2017, 19:55

User avatar
X
paecific.jr
 
Posts: 143
Joined: 04 Dec 2016, 17:56
Location: United States
Main keyboard: IBM Model F 122
Main mouse: Logitech Performance MX
Favorite switch: Capacitive Buckling Springs
Club member: -
 
You can really hear the springs in it and has a loud whack on the bottom out. Insanely pingy for a linear design as well. I'd really like to see a video too, even a phone one, for comparison purposes.
Sangdrax

Unread post12 Oct 2017, 14:33

X
Sangdrax
 
Posts: 45
Joined: 05 Jul 2017, 06:50
Location: Acadiana
Main keyboard: Harris 1978 Terminal
Main mouse: Mammoth
Club member: -
 

Who is online

Users browsing this forum: FSund and 34 guests