Amiga 500 Keyboard Membranes

[rwap]

How much interest would there be in replacement Matsumi A500 keyboard membranes at £20 each? - I would need to order 250 to get that sort of price (!) so this is only tentative at the moment.

Would these also fit the A500+ ?

[rkauer]

Will fit in A500+, it have the very same keyboard.

[jimbob]

Unfortunately I'd have to say that £20 is a bit steep, though I understand why it would be hard to get the price down. Otherwise I think replacement membranes are a great idea, for other models too.

Note that not all 500 membranes are the same as 500+. Some have the extra large return and shift keys instead of the blank/international keys.

[lostrego]

This would help also: Those membranes will fit in later C= A4000 and Escom A4000T keyboards too, the Mitsumi ones with spring coil for key recoil, not to be confused with the rubber dome ones (mostly found on A2000, A3000 (T) and early C= A4000D that use a circuit board instead of a membrane).

There spring coil ones are basically the same keyboard than the one of the A500 but with few minor differences.

---------- Post added at 00:29 ---------- Previous post was at 00:24 ----------

Note: the above mentioned spring coil A4K/T Mitsumi keyboards all have the extra blank/international keys.

[rwap]

This is always the problem with the Amiga - which keyboard membrane to produce - I am not sure which A500 one I have - I presume it is the A500 keyboard without the extra blank key (the left hand shift button abuts the Z key) - is that what you mean?

Is that the wrong model, would it be better to produce them for the A500 with the extra shift key - in which case, I need another A500 keyboard and membrane !!

[rwap]

This is the keyboard I have already - which model is it though?

[rkauer]

ALL Mitsumi A500 keyboards have the same membrane, disregarding the number of keys over it.

On larger Enter/Shift keys the unused contacts are simply covered by the larger keycaps and the actuators are not installed.

The "rubber coil" keyboards might use membranes or PCB circuits, but the membrane units have the very same connection to the interpreter circuit of the A500 with minor differences in the hardware. The membrane will be always the same.

As far as I knowthe most needed membrane is the green A600 (Mitsumi, again), which is poor in reliability.

[jimbob]

I don't think that's correct. There are at least two types of A500 membrane, mitsumi part numbers 56 A619A and 56 A619B.

The A part does not have contacts for the extra keys and I'm not sure everything else lines up perfectly either. I can't actually check this at the moment because the ones I replaced have been returned to their owners and I sent the faulty ones to TheRogue who thought he might be able to clone them.

There is also a third type which has a different two part connection to the controller board, not sure about its key contact layout.

@Rwap the one in your pic has the big keys, I guess you better open it up to check whether or not it has unused contacts on the membrane.

[rkauer]

What I know for sure is the one with extra contacts will fit in the ones with less contacts without any problem.

The ones with two connectors are not Mitsumi, they are made by Samsung.

[rwap]

ALL Mitsumi A500 keyboards have the same membrane, disregarding the number of keys over it.

On larger Enter/Shift keys the unused contacts are simply covered by the larger keycaps and the actuators are not installed.

The "rubber coil" keyboards might use membranes or PCB circuits, but the membrane units have the very same connection to the interpreter circuit of the A500 with minor differences in the hardware. The membrane will be always the same.

As far as I knowthe most needed membrane is the green A600 (Mitsumi, again), which is poor in reliability.

OK thanks - I will have a look to see if it has the extra contacts - presumably under the Enter key and the bottom left shift key ??

I can look into A600 membranes too - but need a keyboard unit and membrane to do this!