IBM 5251 Beamspring with DMAs CommonSense

__red__

11 May 2017, 01:07

So, I've been working on getting this fine 5251 Beamspring to get DMA's CommonSense working with it.

tl;dr - life is good.

My biggest concern right now with any design is that I've not managed to locate an edge-connector which is accurate enough in its specs for board thickness that I was willing to trust. A loose connector means your calibration values will either wander over time / temperature or columns / rows will just stop working until you re-seat.

As I'm prototyping I decided to solder the pins directly on like so using male colour-coded Jumper cables like so:
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What are the colours I hear you ask?
[*] Red - Rows.
[*] White / Green / Yellow - Different locations on the protoboard for columns.
[*] Black - Da Errfs.

So, to the protoboard - it looks like so:
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Now the colouring probably makes more sense as you can see that the columns are grouped. Why oh WHY did I align the columns in that strange round-in order? I'm paranoid about cross-talk so I figured I just wouldn't take the risk.

The observant may also notice that I soldered in female sockets along the edge. As I'm prototyping I know for sure I was going to be re-locating cables around so I made my easy. Now they're in a permanent spot I simply dropped a dab of solder on each one to keep the male jumper engaged with the female socket.

Finally - da errfs:
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Yeah - I can do better and I will... but that will be done properly when I'm done with the cleaning.

I have to say - this is pretty shiny. Full details to follow when I'm not being run out the door.

Enjoy!

DMA

11 May 2017, 01:29

__red__ wrote: ..that I've not managed to locate an edge-connector which is accurate enough in its specs for board thickness that I was willing to trust.
Which raises a question - what IBM was actually using.
Haven't seen a beamspring controller - but it looks like they just use standard edge card connector (rated for min. 1.57mm IIRC). If it didn't bother IBM - why should it bother you?

What's the part number on the connector? There must be something there.

__red__

11 May 2017, 02:57

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It's visibly thinner than one is used to seeing...

orihalcon

11 May 2017, 19:10

Why not just desolder the pcb connector from the original controller?

Glad to see common_sense in action! Awesome job!

User avatar
seebart
Offtopicthority Instigator

11 May 2017, 19:18

Wow, impressive progress. Now I have a good excuse of putting off my Beamspring restprations so long. :mrgreen:

__red__

12 May 2017, 16:06

orihalcon wrote: Why not just desolder the pcb connector from the original controller?

Glad to see common_sense in action! Awesome job!
When I modify keyboards for which I own only one I try and do it with the least amount of modification possible. The original controller is in an anti-static bag with the original (dated) cable just in case I want to revert one day.

Fkazim

19 Jun 2019, 14:00

Great job on converting your IBM 5251 Beamspring but I would just like to ask how could you connect the solenoid driver up to the CY8CKIT-059 development board?

if you could help me out with that it would be much appreciated.

DMA

20 Jun 2019, 16:38

there are "exp header" pins - those should go to solenoid board

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