Re: 6502 CPU Schematic

["Stephen Shaw" <bottrawler@junkbuster.zzn.com>]

On Thu, 19 Dec 2002 09:01:45 +0000, Yves McDonald wrote:

> Hi Bryan,
> 
> You are tackling something big: as much as I can remember, the original
> MOS technology 6502 was a power-hungry NMOS device which memory cells
> (registers, program counter, status reg) were dynamic cells to reduce
> transistor count.  That imposed a minimum clock frequency.  Being an
> ancient device, I wonder if electrical schematics do exist at all or if
> the engineers just created the chip by drawing the required photographic
> masks.  Rather than contemplating a mess of transistors, I'd rather go for
> the logic diagrams which break the microprocessor into its major
> components: registers, ALU, buses and instruction decoding logic.  The
> latter is probably the most complex component.
> 
> The problem with studying the 6502 is that you will miss all the 'C02 and
> 16-bits instructions implementation.  You'll have to ask Western Digital
> for data on the 65816 and I'm not convinced they are willing to give
> freely that kind of info.  Based on personnal experience, I don't think
> they will: in a related case, I asked Futaba for schematics to
> troubleshoot a defective, obsolete 1991 R/C model airplane radio receiver
> and my request was politely denied.  From there, I decided to dump the
> whole set to the recycle bin :(.  I whish companies would be more open
> about their obsolete technologies (Apple, do you hear that about GS/OS
> sources? :-)
> 
> An approach I was considering is to have a modern, insanely fast RISC
> processor to emulate a 65816 then scale up the architecture to 32 bits
> rather than picking up where WD has left.
> 
> Bryan Parkoff wrote:
> 
>>     Do you know where can I find schematic that is INSIDE 6502 CPU only,
>>     but
>> not for Apple II motherboard.  I will be able to study how 6502 CPU
>> work.
>>     It is my goal to build CPU that will support 32 bits and 64 bits
>>     like
>> 65832 and 65864.  All PCI slots, AGP slots, DIMM, and all modest
>> hardware will be designed with new CPU in a motherboard.  It is like
>> restoration for Apple II with 32 bits and 64 bits.
>>     What do you think about my idea?  I feel bad that PowerPC will be
>>     out of
>> business very soon and Apple Computer, Inc does not have choice but have
>> to port Mac OSX to Intel, but I tell them to design their own CPU --
>> 65832 or 65864.  It will profit with great sales at lower costs.
>> 
>> --
>> Yours Truly,
>> 
>> Bryan Parkoff
>> BParkoff@satx.rr.com
>> 
>> 
>> 
>>


I still have the original Synertek 6502 manual. Shall I start scanning it?