SVI-605b hdd info

Hi looking for any info on the svi-605 hdd that some expanders had.. i have the 601 & 605A and 605B but not the one with hdd..
my main 605 has all slots full, rs232,80 col card, printer card, 2 x 64kb cards, plus 2 x dsdd drives. and have a reset switch that goes into joystick port.
would like to put a hdd into one just to see it in there... so any circuit diags etc... would be great..
thanks
my main 605 has all slots full, rs232,80 col card, printer card, 2 x 64kb cards, plus 2 x dsdd drives. and have a reset switch that goes into joystick port.
would like to put a hdd into one just to see it in there... so any circuit diags etc... would be great..
thanks