Heath/Zenith Z100 technical...

I just picked up a board set from a Zenith Z-100 (not sure if it was a 110 or 120 model) which had been junked. I threw this out on the sebhc mailing list too, but perhaps someone here knows: a) If the machine's keyboard is completely passive (i.e. just a bunch of switches), or if there's any intelligence to it, b) If the system will start up with no boards plugged in (other than the bitmap display PCB) - i.e. no S100 FDC or winchester, c) If "yes" to the previous, whether the mainboard/bitmap board will function on just +5V and +/-12V (i.e. without the S100 +8V and +/-16V rails) Trying to power up what I have might be fun, but I'm really not sure about the lack-of-keyboard issue - if it's just switches and decoded via the mainboard then rigging something might be possible, but if there's some kind of higher level serial protocol involved then maybe it's too much hassle. I don't have a S100 bus machine kicking around to power things with at present (but of course rigging something would not be too difficult). I'm not sure what kind of details the documentation went into, either - I've got a Z-89 and the docs there are extremely technical, with full schematics, but I'm not seeing any equivalent online for the Z100 series (there seems to be very little out there about them at all - came too late in the S100 era, perhaps?) cheers Jules