Page 8 of 31. Version 1.03 September 2012 Microbee Premium Plus+ | Construction Manual
4. Keyboard Frame & key switch assembly
The Microbee Premium Plus keyboard is made u of a number of arts which includes
individual mechanical key switches, key to s (ca s), a metal keyboard frame and key switch
ada ter PCBs. In lanning and designing the Premium Plus, large efforts were made to try
and rocure key switches that were the same hysical form as the original ones. There was
no exact match to be found. Some came close (like the Cherry brand MX series) but were
cost rohibitive, others had non-suitable shaft styles and so on. All of the key switches that
we looked at also had different in s acings & locations as well. While we could have
scra ed the existing stock of Premium series baseboards and made new ones to suit a
different style of switch, this was deemed to be wasteful & ex ensive. Seen as the Premium
Plus is a limited edition kit, the best solution was to rovide a small ada ter PCB for each of
the new key switches, so that the assembled switch would then suit the original PCBs. This
also made the solution suitable for eo le who want to re lace the keyboard in other
Microbee models.
4.a Key switch assembly
Assembly of all of the key switch ada ters & fitting them to the key switches takes quite an
amount of time. You can ex ect to s end 2 hours working through the whole lot of keys, so
have some atience & take a break when you need to because it is better to s end as much
time as it needs to do a great job rather than rushing it through. If done well, you will have
a decent keyboard for your Microbee that will last well. If you rush in assembling them, it is
likely that you will have keys that don’t work as well as they should.
In your kit, you will have a bag s ecifically of keyboard bits. This includes the key to s, key
switches, gold PCB ins, mounting hardware and so on. There is also a PCB su lied that
has 68 (64 needed, lus 4 s are) key switch ada ter PCBs in a frame.
All of the individual ada ter PCB’s are held
together in the frame with breakout tabs.
That is, on the edges of each PCB there is a
little bit of PCB material that connects one
PCB to another to hold all of them in the
frame while the board is being manufactured.
At these oints there are very small holes
which rovide a breaking oint. If this oint
is flexed, it will break a art & each individual
PCB will come away from the others. Refer to
the hoto to the right which shows some of
the key switch ada ter PCBs broken out from
the frame.
