Re: Apple //f...

["Robert R. Dell" <robertdell@sprintmail.com>]

Tony Cianfaglione wrote:

> Found this on the net awhile back...
>
>               The Apple //f: A Possible Future for the Apple //
>                                      by
>                                 Todd Whitesel
>                                 28-Feb-90 v.3

The date on this should tell you something.  Since this original posting, Apple has sold all rights to the Apple // line to Sun Remarketing and has discontinued the line themselves.


> Memory System:
>
> - System RAM is expandable to 12 Megabytes via 8 industry standard SIMM
>      sockets and is mapped to memory banks $00-$BF
> - 256K, 1M, and 4M SIMMs are supported in a variety of configurations having
>      small upgrade steps between them
> - DRAM controller supports high speed access modes to improve cache and DMA
>      performance

Well, I almost MADE a memory card that does exactly that AND works in both rev 1.0 and rev 3.0  //GS machines with no jumper settings.  When I found out Apple has discontinued their line, I scrapped my ideas on it.

 >I/O System:

>
> - Serial Communications Controller is supported by the DMA controller for
>      negligible overhead in serial port and AppleTalk reception
> - SCC registers are now memory mapped to assist time critical serial and
>      AppleTalk drivers
> - 128K per expansion slot is reserved for faster expansion cards as Banks
>      $E2-EF
> - I/O ($Cxxx) in Bank $E1 is allocated to internal I/O functions or is
>      reserved for future use
> - SWIM and synchronous SCSI interfaces are controlled by a separate disk
>      coprocessor with 32K dedicated RAM for 1:1 interleave reads and built-in
>      cache support; the RAM interface is DMA compatible and the DMA
>      controller handles the actual moving of the disk data

You appear to be forgetting the needs of the tinkerers for having minimum of 12 logic inputs and 12 logic outputs.  I had to make a card for the Mac to do just this.