deskthority

After seeing the XTant, FSSK/FEXT, Model MF, and the 3277 PCBs, I'm wondering what the PCB of the 50-key IBM 4740 keyboards look like. (That's the 10 x 5 ortholinear one). I know that a number of people here have them. Has anyone scanned the PCB or at least taken a good picture?

References:

• XTant: workshop-f7/bringing-the-ibm-pc-xt-into ... ml#p185610
• FSSK/FEXT: workshop-f7/f-ssk-t10744-630.html#p298411
• Model MF: group-buys-f50/model-mf-drop-in-kit-for ... ml#p338275
• 3277 PCBs: workshop-f7/xwhatsit-cs-compatible-ibm- ... 16867.html

I think it'll be relatively simple to build one for the M50! They already have the metal plates, all we need is the PCB and Model F flippers and it'll practically be the same as the 4704 F50.

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Yes, you I have previously confirmed that the 4704 Model F50 PCB fits the M49/M50 and internal assemblies are identical. All you would need is to remake the same PCB and add Model F hammers and an xwhatsit and you would be good to go. If anyone can design the PCB, I can run the group buy and even sell kits that have all of the above included.

Only thing you might have to do is a slight case modification with a dremel for the xwhatsit if there are any plastic bits in the way.

Alas, I don’t have easy access to an F50 to do a scan of it or send pictures :/

Would an F50 PCB be suitable for an M50 keyboard? I think it has the necessary space for the controller, but never opened mine.

orihalcon wrote:Yes, you I have previously confirmed that the 4704 Model F50 PCB fits the M49/M50 and internal assemblies are identical. All you would need is to remake the same PCB and add Model F hammers and an xwhatsit and you would be good to go. If anyone can design the PCB, I can run the group buy and even sell kits that have all of the above included.

Only thing you might have to do is a slight case modification with a dremel for the xwhatsit if there are any plastic bits in the way.

Alas, I don’t have easy access to an F50 to do a scan of it or send pictures :/

This could complement the F62 remakes perfectly! A main 60% board and a side macropad for numpad/arrow cluster would be amazing!

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you guys are talking without thread starter as usual

TerminalJunkie wrote: After seeing the XTant, FSSK/FEXT, Model MF, and the 3277 PCBs, I'm wondering what the PCB of the 50-key IBM 4740 keyboards look like. (That's the 10 x 5 ortholinear one). I know that a number of people here have them. Has anyone scanned the PCB or at least taken a good picture?

of course, kishy did.
http://kishy.ca/?attachment_id=1678

Thanks, hasu! Some questions:

• There is a copper dot above each capacitive pad. Does anyone know what it's for? My XT PCB has them too.
• There is a pad and hole near the end of each row trace. Are these test points left over from development?
• Some of the column pads in the bottom layer (http://kishy.ca/?attachment_id=1676) have pink/white dots on them. Does anyone know what they are or signify?

A clue: the two copper dots are right under the "feet" (pivot points) of the flipper. I still don't understand their purpose in the design. If it were just to lift the flipper a little, they could have made the feet taller. Perhaps the dots make those parts of the PCB smoother or more resistant to wear?

Any clue about the f50 pcb after half year past?