Subject: Re: Apple //f...
From: "Robert R. Dell" <robertdell@sprintmail.com>
Newsgroups: comp.sys.apple2
Date: Sat, 03 Jul 1999 17:35:50 -0400
Content-Transfer-Encoding: 7bit
References: <Pine.GSO.3.95.iB1.0.990627025921.20848A-100000@halifax.chebucto.ns.ca>
X-Posted-Path-Was: not-for-mail
X-Accept-Language: en
X-ELN-Date: 3 Jul 1999 21:35:50 GMT
X-ELN-Insert-Date: Sat Jul  3 14:45:06 1999
Organization: EarthLink Network, Inc.
Lines: 43
Mime-Version: 1.0
Reply-To: robertdell@sprintmail.com
NNTP-Posting-Host: sdn-ar-001ohwarrp003.dialsprint.net
Message-ID: <377E8231.D58DED90@sprintmail.com>
X-Mailer: Mozilla 4.6 (Macintosh; U; PPC)


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.