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Page 10 of 31. Version 1.03 September 2012 

      Microbee Premium Plus+ | Construction Manual 

 

1. With the PCB adapter board spread across 
the up-turned keyboard frame, insert 3 PCB 
pins (short end through the holes) 
 

 

2. Place a ‘broken-out’ adapter on top so that 
it is then sitting on the collars of the PCB 
pins (using 3 pins keeps the adapter PCB 
level) 

 
 

 

 

3. Solder the 2 required pins, leaving the 3

rd

 

un-soldered, and then remove the adapter & 
trim the pins as described earlier. 
 

 
 
Obviously, as you do more and more of the 
adapters, the PCB frame will have less and 
less adapters in it and the last few will 
probably have to be done with no support 
from the frame. 
 
One other tip is that if you line the adapter 
that you are working on up over a key switch 
hole in the keyboard frame below it, you can 
press down on the centre of the adapter so 
that it ensures that all of the PCB pins are 
pressed ‘up’ against the bottom of the 
adapter as you solder it.  This also aids in 
making sure the pins are straight & parallel. 
There is a bit of a ‘knack’ to doing this, but 
after doing a few, you should see it get 
easier. 
 
Remember that only 64 key switches are 
needed, so the last 4 adapters in the frame 
do not need to be assembled.  

 
 
 
 
 

Summary of Contents for Premium Plus +

Page 1: ...Page 1 of 31 Version 1 03 September 2012 Microbee Premium Plus Construction Manual Premium PLUS Construction Manual Microbee Technology Pty Ltd P O Box 709 Lilydale Victoria 3140...

Page 2: ...Introduction Requirements 3 2 Getting Started Preparing the Baseboard PCB 3 3 Passive components 5 4 Keyboard Frame Key switch assembly 8 5 I C sockets and PCG ram adapter PCB 14 6 Integrated Circuit...

Page 3: ...he unit It is important to note that once construction has started the kit cannot be returned for a refund should you decide that the task is beyond you Check off all of the components against the par...

Page 4: ...d 8501 4 0CR this can be found on the PCB on the component side rear right side near the 5 Pin DIN socket position The PCB has a number of configuration jumpers on it where the default position is mad...

Page 5: ...cap single on tape 1 x 47pF cap single on tape 1 x 470uF 25v Electrolytic cap Polarised You can do these in any order but take care with the polarised components that you insert them so that the mark...

Page 6: ...at the left end signifies pin 1 Make sure you line up pin 1 with the marking on the PCB Mounting the 11 x 1N914 4148 diodes is straight forward but make sure the band on the body of the diode matches...

Page 7: ...sistor go into pins 5 6 of the IC location and the BASE lead gets bent backwards is soldered into IC23 pin 3 Note that the round side of the transistor is facing toward the edge of the PCB Also a LINK...

Page 8: ...ard in other Microbee models 4 a Key switch assembly Assembly of all of the key switch adapters fitting them to the key switches takes quite an amount of time You can expect to spend 2 hours working t...

Page 9: ...red into the main PCB later 4 Solder the finished adapter onto the back of a key switch Make sure that the adapter is flat against the back surface of the key switch This is important as we do not wan...

Page 10: ...f the adapters the PCB frame will have less and less adapters in it and the last few will probably have to be done with no support from the frame One other tip is that if you line the adapter that you...

Page 11: ...me Mounting the 2 x 7805 5volt regulators is next Both regulators bolt directly to the keyboard frame underside with a thermal transfer silicon rubber pad The regulator for the right hand side eventua...

Page 12: ...with the holes in the PCB you can tighten the bolts to keep it that way Do NOT solder the regulator to the PCB at this time The left hand side regulator Trim the legs back to just near the wider part...

Page 13: ...lift the frame main PCB out of the bottom of the case ensuring that it all stays together and then tack solder 1 pin of each key switch This is a bit of a juggling act but can be achieved by holding...

Page 14: ...tive to pin 14 should read 5 0v 10 If these are measured o k then construction can continue and the un soldered pins on the 5 key switches can now be soldered 5 I C sockets PCG ram adapter PCB Sockets...

Page 15: ...onal pins to start with For example on a 14 pin device solder pin 7 pin 14 to the board leave the rest for now Then once all ICs are in position and verified for correct type orientation solder the re...

Page 16: ...they are upright is to use the core board as a guide with the sockets plugged onto the pin strips Right side 25 way strip 2 way socket Left side 25 way socket strip Put the core board in location on t...

Page 17: ...st enough heat to melt the solder and form a decent joint on the PCB Applying prolonged heat to the key switch pin will melt the solder on the switch adapter and if excessive heat is applied the pin m...

Page 18: ...e 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 p...

Page 19: ...C71 not that much should have changed in that area since the previous check It is however a simple test easy to carry out so best to do it anyway The voltage checks can also be done without the corebo...

Page 20: ...like the screen shot on the right don t forget that you will only have monochrome video so no color The keyboard test is the first item to run and for now just press ESC twice to bypass it All items...

Page 21: ...m Plus The last thing to do of course is to put the casing together The baseboard is held into the bottom of the case with a screw flat washer at either side of the keyboard frame The kit was shipped...

Page 22: ...DIP14 IC73 25 49 57 4 74LS10 Triple 3 input NAND gate IC65 1 74LS139 Dual 1of4 decoder DIP16 IC61 1 74LS645 245 Octal Buffer bi directional DIP20 IC17 26 29 30 31 5 74HC32 Quad 2 input OR gate HC DIP1...

Page 23: ...RSIP4K7X9 Resistor SIP 4K7 x 9 10 pin RN2 RN3 2 RSIP10K0X9 Resistor SIP 10K x 9 10 pin RN1 1 330R 1 4W 330R 1 4W resistor TH R15 22 27 28 4 270R 1 4W 270R 1 4W resistor TH R24 1 82R 1 4W 82R 1 4W res...

Page 24: ...Socket 24 PIN 300mil Skinny DIP IC19 20 21 62 4 IC Socket 24 PIN 600mil DIP IC50 1 Keyswitch Pushbutton 64 PremPlus keyboard Frame 1 PremPlus Keycap set 1 M3x6 bolts 2 M3 nut 2 Spring washers M3 2 TO...

Page 25: ...anual 11 Check photos This section contains photos of the Premium baseboard at various stages of assembly They have been included here as a reference for you that can be referred to and compared to wh...

Page 26: ...Page 26 of 31 Version 1 03 September 2012 Microbee Premium Plus Construction Manual Check Photo 2 resistors installed...

Page 27: ...Page 27 of 31 Version 1 03 September 2012 Microbee Premium Plus Construction Manual Check photo 3 4 5 Close up of passive components...

Page 28: ...Page 28 of 31 Version 1 03 September 2012 Microbee Premium Plus Construction Manual Check photo 6 Regulators installed with Keyboard frame...

Page 29: ...Page 29 of 31 Version 1 03 September 2012 Microbee Premium Plus Construction Manual Check Photo 7 baseboard complete no key tops installed...

Page 30: ...Page 30 of 31 Version 1 03 September 2012 Microbee Premium Plus Construction Manual...

Page 31: ...Page 31 of 31 Version 1 03 September 2012 Microbee Premium Plus Construction Manual...

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