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Hardware idea

	How difficult would it be to make an Apple II block device card that
had the following:  a SIMM or DIMM slot for a 32M memory card, a ProDOS
block driver (in ROM) and possibly a NiCd or Lithium (or whatever)
battery to power the ram when the main power is off?  Effectively, a
really huge ram disk.  The ram would NOT be accessible to regular system
software, like Appleworks or GS/OS, just to the ProDOS block driver.

	I am thinking that the block driver could fit in it's entirety in the
cx00-cxff ROM space (only 256 bytes needed).  It would bank switch the a
512 byte RAM window into c800-c9ff, or maybe a larger RAM window into
c800-cdff.  (The "hole" at cfff would make using ce00-cfff a bit
tricky).  If 256 bytes of ROM is not enough, then I suppose that we
could place additional ROM at ce00-cffe.

	What RAM type would be better, static (no refresh needed) or dynamic? 
I suspect that keeping dynamic ram saved during CPU power off would be a
pain.  (But I've seen it done before:  Inside my Zelda I Nintendo tape
is the standard two rom chips, a pal, a battery, a 2K dynamic ram chip
and a 6502....  I haven't a clue why they did not use static ram...)

	Will GS/OS be able to use this device if it contains just a standard
ProDOS block driver?  Based upon the recent post about a home brew IDE
interface and Dave' comments about a smart port driver... How difficult
would it be to make the card use a smartport interface instead of prodos
block driver?  Maybe then you could slap on a couple of 256M dimms... 
pc100 ram for the Apple II!

	I think that this IO card would be absolutely cool.  A completely solid
state hard-drive.  I suspect that it would be faster than any non-DMA
SCSI card out there.

	This is weird.  This post seems like deja vu.  Did I post something
about this a few months ago?  Anyway...

-- 
djenkins@usb.com                           Universal Savings Bank.

The three most dangerous things are a programmer with a soldering
iron, a manager who codes, and a user who gets ideas.