Page 18 of 31. Version 1.03 September 2012
Microbee Premium Plus+ | Construction Manual
Fitting the rest of the key tops is straight forward. Note that the arrow keys can be
interchanged with each other unlike the original key top set in which the up arrow, down,
left & right arrows were all specific to a particular position.
The original keys had a ‘high side’ and ‘low side’ (i.e. they were an angled / sculpted design)
whereas the new key tops are uniform in shape.
When finished, the keyboard should look like the picture below.
Socketed ICs
All of the remaining ICs can now be put into their sockets. Pay attention to the orientation,
checking where Pin 1 should be located for each as you plug them in.
The ICs that are socketed are as follows:
IC1 – 6545, IC9 – Z80APIO, IC33 – Z80ACPU, IC50 – Font ROM (2532),
IC19,20 & 21 – CY7C128A, IC53/4 - CY62256 SRAM, IC61 – 74HC139 and
IC62 - the GOLD PAL
Once done, the baseboard should look like the one in the following photo.
