Re: Steal RAM -- Question

["mdj" <mdj.mdj@gmail.com>]

Bryan Parkoff wrote:

>     Okay, I understand.  When AE RAMFactor or any memory card is installed
> in slot 1 through 7, SELECT DEVICE is mapped in C08X * 16 and I/O DEVICE is
> mapped in Cx00-CxFF.  If you build new peripheral card, are you limited to
> use 16 I/O switches in C08X * 16 while reading firmware including I/O
> switches from I/O DEVICE ROM.  Correct?

If you build a new card, you can do what you like :-)

>     When AE RAMFactor card is active, data should always be accessed in
> motherboard RAM while it can be transferred from motherboard RAM to
> RAMFactor card.  It is impossible to disable motherboard / auxiliary RAM and
> use RAMFactor card as primary RAM $0000-$FFFF except $C000-$CFFF.  Only
> other RAM card can disable motherboard / auxiliary RAM.

Data from the RAMFactor, or any other 'slinky' card is only available
through a 1 byte window in the I/O space.

I'm not aware of any memory card that uses the INHIBIT' line to expand
memory, with the exception of multibank memory cards for the II/II+
that provided multiple language card banks.

It's difficult to conceive of a design that utilises this feature,
doesn't do what either slinky cards or RamWorks style cards already do,
and doesn't clobber something in some way as to make it undesirable.

Matt