Re: how do I use a snapshot card?

["Ron Clarke" <user@clarke-ron.karoo.co.uk>]

I have the documentation post me an address any i will send you photocopies

It may take some time as I am in the UK


David Empson <dempson@actrix.gen.nz> wrote in article
<1dn58yr.1x4e98t1fitf3sN@dempson.actrix.gen.nz>...
> md <mdickins@brightok.net> wrote:
> 
> > I bought a snapshot card but I haven't a clue how to use it or really
> > what it does.  It has a connector that looks like it might plug into
> > the game socket on the mother board and a cord with a button on it.
> > There is also a separate piece that looks like an empty chip socket
> > similar to what might fit in the game socket, this piece really has me
> > curious. 
> 
> That sounds suspiciously like the method used by genuine Apple language
> cards to hook into the memory bus.
> 
> With a language card, there is a short ribbon cable with a 16-pin DIL
> plug, that needs to be inserted in place of a RAM chip on the
> motherboard.  The chip that is removed gets inserted into the empty
> socket on the card.  The language card then makes use of the memory
> refresh signals being generated by the motherboard to refresh its
> on-card RAM.  In effect, it is just piggy-backing off one of the RAM
> chips to get this information.
> 
> This only works with an Apple ][ or ][+, since later machines don't have
> the same type of RAM.
> 
> I can't be certain that the same applies to this card, and I wouldn't
> recommend experimenting without proper documentation.
> 
> 
> I haven't seen a "snapshot" card, but I know that it is similar to a
> "wildcard", which I did see once.
> 
> These cards work on the principle of taking a snapshot of the entire
> memory contents and writing it out to disk.  This is done when you press
> the button, which causes a non-maskable interrupt.  The card intercepts
> the normal handling of the NMI by overriding motherboard memory
> (particularly the ROM) and taking control of the CPU.
> 
> While in control, the entire memory is copied onto the card, then you
> reboot and run software that lets you save the data to disk.
> 
> This is intended to be used as a deprotection method - once the
> copy-protected software is loaded into memory, you can effectively save
> it to a normal disk.  To run the software later, you simply BRUN the
> file that was created by the card (or perhaps a front-end loaded, since
> it wouldn't be able to load all of memory in one hit).
> 
> I suspect this particular card can only be used to capture software that
> works in a ][ or ][+ and only requires 48K of RAM.  You would need the
> software that went with it to be able to do anything useful.
> 
> -- 
> David Empson
> dempson@actrix.gen.nz
> Snail mail: P.O. Box 27-103, Wellington, New Zealand
>