Micronik 1200 busboard and power adaptor usage.

[stamatiou]

Hello,i am trying to revive my amigas and i would like to ask you if the power adaptor is needed for an amiga 1200 fitted inside a micronik infinitiv tower with a busboard.I mean at the moment the amiga does powers on without the usage of the power adaptor but is it safe considering i will be using a mk3 cyberstorm or a wrapengine 68060? I remember i bought new the infititiv tower with a busboard already fitted and i remember there was no power adaptor in between the keyboard pcb and the a1200 mobo yet the amiga was working yet the power supply had hot but not burning cables.Do you know perhaps where i can find one? Thank you.

 

[BLTCON0]

The busboard must be directly powered from the AT PSU as that's what in turn gives enough juice for the CS MK3 etc. I suspect the A1200 motherboard gets its power via the busboard, too, so the small power adapter may not be necessary.
My guess is the small power adapter is there as a convenience feature in case you don't want to install the busboard.
Of course in that case plugging a PSU lead into the motherboard floppy port would also be enough to power a basic A1200 config, but you'd miss the -12V line, which is necessary for audio. Using the provided power adapter instead, you get all voltages (+5, +12 and -12) as if they were coming from an original external Amiga PSU.