Re: IIGS Acceleration Idea


"Ed Eastman" <noone@xxxxxxxxxxx> wrote in message
news:drl9kf$7rr$1@xxxxxxxxxxxxxxxxxx
> Greg Andrzejewski wrote:
>> A stock GS has a "slow" mode at about 1 Mhz and a "fast" mode at 2.8
>> MHz. What is preventing us from simply making this "fast" mode something
>> like 10 MHz?
>
> In a word, the FPI/CYA chip. This is the thing that times and actually
> does everything, from the ram refresh to the slot timing to the mainboard
> and slot RAM addressing. To speed up the IIgs you'd have to implement a
> new CYA chip to produce all the timing and address signals for the main
> board plus the faster clock for the IIgs.
>
> How to accelerate your IIgs without recreating the wheel:
> 1. Overdrive: Replace the CPU with a high speed CPU and simple 20x clock
> circuit. Monitor the Speed softswitch, and the HIGH pulse of the CPU
> clock along with the 'internal cycle' signals off the CPU. Turn those
> signals into drive for overclock circuit. Each internal cycle will be
> then 1/10 the normal time and be ready for the next activity at normal
> speed. Shoudl be 100% compatible and break nothing.
>
> 2. Freewheeling 65816: A little more complex, 100% compatible. Add fast
> CPU, clock, Ram and refresh circuit. Additional circuit to monitor the
> low clock pulse to 'freeze' the CPU to obey the FPI/CYA. Obviously
> circuit to route and clock Bank 0/1 (E0/E1) and Rom and Softswitches to
> main board, run the rest in the CPU RAM.
>
> 3. Reinvent the wheel, er IIgs mode: Build the same thing but instead of
> freezing the CPU on low clock from main board, ignore the main board
> completely except for: video ram updates and slot access. Monitor speed
> softswitch, Rom access, Softswitch access, drive activity, downshift/ sync
> to main board clock as necessary. aybe load ROMs to RAM and eliminate rom
> slowdown.
>
> Want a block diagram? Want a wiring diagram? Can your read minds? THen
> nevermind.
>
> Thankx,
> Ed

Ed,

I have to say -- do 1 GHz (GigaHertz) crystal osc chip exist? If so,
you will have to redesign Apple //e or Apple IIgs motherboard. 65816 CPU
will run at 1 GHz. One GHz crystal osc is divided by two or four to handle
RAM as DIMM (533 MHz or beyond?). Then 1 GHz is divided by 75 (Yes, it is
seventy-five) to handle video at 14MHz to support NTSC TV and monitor.
You have to find some ways to work with sound, floppy drive, etc that
they only handle at 1MHz while 3.5" floppy drive and other devices handle at
2.5MHz. You would need to use DMA to prevent from CPU and video scanner
sharing the same RAM like real Apple //e and Apple IIgs have. If it does
not work, you will need to design a special chip which it allows to delay
video and other devices until CPU is processing million cycles (less than 1
GHz) before video can be resumed to process in turn.
Michael Mahon and other folks said that it is impossible, but you have
to understand how timing generator works. It is what "Understanding the
Apple //e" manual explains everything how timing generator works.
I wish that it would WORK when you reinvent Apple IIgs' design of
motherboard. If it does work, I can say that it is faster than Pentium IV
2-4 GHz.

Bryan Parkoff


.

Relevant Pages

  • Re: IIGS Acceleration Idea
    ... from the ram refresh to the slot timing to the mainboard and slot RAM addressing. ... To speed up the IIgs you'd have to implement a new CYA chip to produce all the timing and address signals for the main board plus the faster clock for the IIgs. ... Replace the CPU with a high speed CPU and simple 20x clock circuit. ... you will have to redesign Apple //e or Apple IIgs motherboard. ...
    (comp.sys.apple2)
  • Re: IIGS Acceleration Idea
    ... from the ram refresh to the slot timing to the mainboard and slot RAM addressing. ... To speed up the IIgs you'd have to implement a new CYA chip to produce all the timing and address signals for the main board plus the faster clock for the IIgs. ... Replace the CPU with a high speed CPU and simple 20x clock circuit. ...
    (comp.sys.apple2)
  • Re: 3200+ auto reads 1900+
    ... I also have an asus board /a7n8x deluxe/ and it runs great.Same ram and cpu. ... clock 2.5 RAM I can set this as aggressive. ... The configuration on both systems is the same ...
    (microsoft.public.windowsxp.hardware)
  • Re: P4S800-MX SE cpu compatibility
    ... For example, could I run a 800FSB cpu, with PC266 ram? ... It is hard to tell what combinations of CPU clock and memory ... The Asus hosted forum is here. ...
    (alt.comp.periphs.mainboard.asus)
  • Re: Would a 2nd processor really be a waste of time???? help
    ... > buy another processor and more ram, however this is what one supplier ... > Your server has only 1 processor. ... installation including changing the bios settings and installing the smp ... The second cpu will probably help ...somewhat. ...
    (comp.unix.sco.misc)