Re: Question: Hardware differences between Unidisk 3.5 and 3.5Drive?

[Wayne Stewart <waynes@intergate.bc.ca>]

Mark Cummings wrote:

> Now I'm confused, my UDC card has LASER UDC on the EPROM and VTECH printed
> on the circuit board. I think it is a late model as there is a VLSI surface
> mount chip on it.
> The instruction leaflet has Laser Computer on the front.
> A quick check inside it does not specify that it can't use Unidisk 3.5, but
> it does say Apple 3.5 drive as one of the drive options.

Interesting. I have the card that appears to match your description(7 chip card
about 6"
long?) except it doesn't have VTECH on it anywhere. I t did have Laser on the
EPROM
and in the EPROMs code. All the chips on it have a 1988 date on them.
I have an older UDC card in storage so I can't check the exact specs easily
with about
35 chips(no surface mount ones) and VTECH printed on the board. I seem to
recall seeing
1986 production chips on it and thinking they likely beat the IIgs into
production.


>
> So do I have a Laser UDC or a VTECH UDC ?

I guess both then. I suspected the same manufacterer of my cards given the
EPROM
compatibility. Sometimes it's awkward making statements based on a couple of
hardware examples.

> Ahhhh, I noticed that the eject didn't work on the 1st & 2nd Apple 3.5, I
> thought it may have been a fault in the drive daisy chain board, as I have a
> couple that don't daisy chain too well.

On my laser UDC card the first works but not the seconmd. If you have a burner
that'll do 2764 EPROMs and feel like seeing if an EPROM change will get the
first drives eject button going I can email you the image

    Wayne