Path: utzoo!mnetor!uunet!husc6!uwvax!speedy!cad
From: cad@speedy.cs.wisc.edu (Owner of VLSI software)
Newsgroups: comp.sys.apple
Subject: Re: Some points and a request
Message-ID: <5520@spool.cs.wisc.edu>
Date: 5 Apr 88 19:10:31 GMT
References: <5499@spool.cs.wisc.edu> <1313@PT.CS.CMU.EDU>
Sender: news@spool.cs.wisc.edu
Lines: 52
Keywords: Apple // clone

In article <1313@PT.CS.CMU.EDU>, ralphw@IUS3.IUS.CS.CMU.EDU (Ralph Hyre) writes:
> In article <5499@spool.cs.wisc.edu> cad@speedy.cs.wisc.edu (Owner of VLSI software) writes:
> >	I am planning to build an Apple //e clone
> >that will run at 10 MHz (yes 10).  This should make for one
> Well, everybody is still waiting for Zip chips, where are you going to
> find a 10 Mhz 6502?  Can you still use DIP's and IC sockets at this speed?
> I recommend (Lots of stuff deleted)
I plan to use an 8 MHz 65C02 or 65802 and run it at 10.
This will be very simple.
DIP's and IC sockets will run fine at 10MHZ, you can even use ECL (10K 
series) with wire wrap, which is what I plan to use.
All I really want is a Fast Apple //e.  It will have extended memory.
It will not have a 24-bit address bus.

> 
> Keep the 65832 and virtual memory in
> mind (even the 65816 has some capabilities for this.)
> 
> A GS 'clone' would be nicer, you might even get away with 
A GS clone would necessitate buying a GS and getting to know
its hardware as intimately as I know the ][+'s and //e's.
I really want to run C, BASIC, and Appleworks fast, and just build
the thing for fun.  (This is fun?)

Some more ideas like:

	an 8 MHz 65C02 or 65802 or 65816 running at 10MHZ
	(This should be no problem, really)
	a divide by n counter (FACT or Fast) to switch
		clock speeds
	an EPLD Eraseable programmable logic device (PLA)
		for address decoding, and automatically
		slowing the clock when slots are addressed,
		to retain compatible slots.
	a 6545 for display (text only at first), with another
		EPLD to translate Apple screen memory to 
		6545 format.
	(This 6545 will need another 6502 running at 1 or 2 MHz,
	buffering screen info, or there will be some hellish
	bus contention circuitry which I don't want to deal with.
	There may also be a buffer between the processors to
	deal with the difference in speed.)

	Perhaps a microcontroller (like 68705) to copy EPROM into
	fast RAM, because cheap EPROMs are 200ns or slower.

How's that for a start?
> Internet: ralphw@ius2.cs.cmu.edu    Phone:(412)268-{2847,3275} CMU-{BUGS,DARK}
> Amateur Packet Radio: N3FGW@W2XO, or c/o W3VC, CMU Radio Club, Pittsburgh, PA

Chris Schumann			chris@leyden.cs.wisc.edu
(Don't mail to cad@speedy, please)