Re: What 3.5 drive will work with my //c?

[paulb@ece.nwu.edu (Paul Brazis)]

In article <24SEP199723134134@vax2.concordia.ca>,
Mitchell Spector <spec@vax2.concordia.ca> wrote:
>In article jsassman@binary.net writes...
>
>>My ][C says '0' when I enter that basic 'program'--
>>PRINT PEEK (64447)....But it has both a Rom upgrade
>>to use the Unidisk drives--I currently have two of
>>them connected, AND it has the Applied Engineering
>>Z-Ram Ultra 1 meg board....But according to your
>>post, Nathan, this model should not be capable of
>>memory expansion.  If that's correct, then when I
>>run Appleworks and it says I have a desktop of some
>>644k available it must be kidding around?? ;)
>
>    Nathan was correct, the original Apple IIc motherboard (ROM '255' 
>and '0') does not have any memory expansion socket. Apple designed it
>as a closed system with no internal expansion, leaving just the back
>port connectors as the only way to make it grow. However, people came 
>up with ideas, creating hardware "hacks" to get around that limitation.
>The AE Z-Ram board was one such example, you removed the 65C02 and MMU
>chips off the motherboard, plugged the board into those sockets, and
>then moved the chips onto the expansion board. This little trick let
>the non-expandable IIc add more (bank-switchable) memory.
>

IS there any technical information to be had on how this is done? I have the
255 //c, and this could be a neat little project...




>    A few years later Apple saw there was interest in expanding the 
>IIc, so they came up with a new motherboard design that included a
>memory expansion socket. This new motherboard used the ROM '3' and
>ROM '4', and accepted Slinky-type memory boards. When the Apple IIc+
>was introduced, it too had a memory expansion socket, but it wasn't
>quite compatible with the older memory expansion socket of the ROM
>3 and 4 IIc (and the reason my IIc+ still only has a measly 128K of
>memory at the moment :/).
>
>Mitchell Spector
>spec@vax2.concordia.ca