65C02

Thread View: net.micro.atari8

3 messages

[T] Back to Threads [V] Tree View [G] Group Articles

3 total messages Started by Bill Dippert Wed, 13 Aug 1986 17:09

#357

Author: Bill Dippert
Date: Wed, 13 Aug 1986 17:09

21 lines
1872 bytes

Does anyone know much about the 65C02 chip?  I understand from an article
in either Antic or ANALOG that it was pin compatible with the 6502 chip.
Hence I obtained one and swapped it with my 6502 chip in a 1200XL.  Voila,
instead of getting a normal screen, I got an all green screen and nothing
happened.  This was with no cartridge inserted.  With a cartridge inserted
I could not get anything on the screen.  (Altho between tests, I had swapped
the 6502 in and out again to check the computer.)  Finally I gave up and
put the 6502 back in again.  Computer worked fine.  Only thing that I 
noticed was that the chip said that it was a R65C02.  I thought initially
that the R indicated the vendor, but I am wondering -- is there such a
thing as a "reverse chip" -- in other words is what I have a 65C02 chip
with pins reversed (or backwards)?  Has anyone had any success in swapping
in 65C02 chips?  Or is the Atari 6502 a custom modified 6502?  I do notice
that the Atari chip has their part number on it and not the JDEC 6502 
designation.  (Did not Commodore originate the 6502 and if so, is Atari
merely trying to hide the origin?)

				 --Bill--
---------------------------------------------------------------------------
Just hacking away at my hardware, a little saw cut here, a new chip there!!
---------------------------------------------------------------------------

Re: 65C02

#356

Author: jhs
Date: Thu, 14 Aug 1986 15:27

14 lines
1046 bytes

Bill,

I think that is a CMOS chip, and as such may not have enough oomph to drive
the circuits connected to it in the Atari 1200XL, which are TTL.

I think the R means it is a Rockwell chip.

A more interesting question would be whether the 65802 chip from The Western
Design Center, Inc., would drop in and work!  This would give us 6809-like
power with upward compatibility, if what I have heard is true.  Does anybody
know if this would work?

-John Sangster
jhs@mitre-bedford.arpa

Re: 65C02

#363

Author: Ishler.WBST
Date: Fri, 15 Aug 1986 13:41

6 lines
712 bytes

Bill
I don't know about the 1200XL but the 6502 in the 800XL has several of
the pins relocated and a new signal added(halt).The 800XL repair manual
lists the chip as a 6502(modified).

Mike

Thread Navigation

This is a paginated view of messages in the thread with full content displayed inline.

Messages are displayed in chronological order, with the original post highlighted in green.

Use pagination controls to navigate through all messages in large threads.

Back to All Threads