Source
r/apple2•
fontock

Comparable 65C02's ?

Back in the day, I upgraded my Apple IIe's to "Enhanced" by dropping in a CMOS 65C02 and burning new Eproms.

Recently I decided to get my old Apple IIe running again but discovered that the 65C02 was missing. So I bought a few WDC W65C02S's, but was surprised to find they don't work.

Eventually I found the hardware mods at:

http://www.westerndesigncenter.com/wdc/AN-002_W65C02S_Replacements.cfm

You need to bend up a couple of pins and add a jumper. After that it's fine.

But since then I've been trying (out of curiosity) to find some of the original 65C02's. I've purchased various versions, but so far none work. Not even with the jumper mods.

Can anyone help solve the mystery?

Can you tell me exactly what is written on the 65C02 chip in your Apple IIe Enhanced or Platinum please?

(brand and number)

Thanks.

Posted Sep 14, 2017, 7:44 AM UTC

94
redruM69•

Are you sure there isn't something else wrong with the machine?

Also, you can nab the entire Enhancement Kit, which includes the 65C02, for $25 on eBay

1
fontockOP•

Thanks for the reply. Actually I have three Apples, a IIe, a IIe Enhanced, and a Platinum.

When a few more 6502 chips arrive, I'll do some serious testing. I've ordered a ZIF socket so I can swap chips as many times as I like.

I do have an original Apple Enhancement kit from back in the day. FWIW, the ebay Enhancement kit uses a modern WDC chip, with the jumper mods done on a piggyback socket.

Since my original post I've found a huge amount more info, so I think I'm getting closer.

1
fontockOP•

Thanks for the reply. Actually I have three Apples, a IIe, a IIe Enhanced, and a Platinum.

When a few more 65C02 chips arrive, I'll do some serious testing. I've ordered a ZIF socket so I can swap chips as many times as I like.

I do have an original Apple Enhancement kit from back in the day. FWIW, the ebay Enhancement kit uses a modern WDC chip, with the jumper mods done on a piggyback socket.

Since my original post I've found a huge amount more info, so I think I'm getting closer.

1
redruM69•

Are you sure there isn't something else wrong with the machine?

Also, you can nab the entire Enhancement Kit, which includes the 65C02, for $25 on eBay

1
fontockOP•

Thanks for the reply. Actually I have three Apples, a IIe, a IIe Enhanced, and a Platinum.

When a few more 6502 chips arrive, I'll do some serious testing. I've ordered a ZIF socket so I can swap chips as many times as I like.

I do have an original Apple Enhancement kit from back in the day. FWIW, the ebay Enhancement kit uses a modern WDC chip, with the jumper mods done on a piggyback socket.

Since my original post I've found a huge amount more info, so I think I'm getting closer.

1
fontockOP•

Thanks for the reply. Actually I have three Apples, a IIe, a IIe Enhanced, and a Platinum.

When a few more 65C02 chips arrive, I'll do some serious testing. I've ordered a ZIF socket so I can swap chips as many times as I like.

I do have an original Apple Enhancement kit from back in the day. FWIW, the ebay Enhancement kit uses a modern WDC chip, with the jumper mods done on a piggyback socket.

Since my original post I've found a huge amount more info, so I think I'm getting closer.

1
arbee37•

There are 2 different 65C02s. Rockwell made one (and licensed it around) that has different new instructions, which aren't the ones the 65C816 also implemented, and that chip won't work in an Apple II.

The second is WDC's, and thats the one we all know and love and which the 65C816 is back-compatible with.

1
fontockOP•

Unfortunately it seems it's a lot more complicated.

Software wise there's the Rockwell R65C02, which is different to the "standard" 65C02 made by Rockwell, NCR, Synertek, Mitsubishi, Ricoh, and Sanyo, (different again are the GTE and the CSG versions).

Then there's the WDC versions which are different again.

But then Hardware wise there are different manufacturing processes (eg different switching thresholds), and different pin-outs.

And because different Apples used different families of logic chips, and different speed memory chips, there are odd combinations which will work on some, but not on others.

For example I have three different Apples, all of which refuse to ruin with different individual R65C02's. I even have a genuine Apple 65C02 which will run on some Apples, but not others.

I'm waiting for some more chips to arrive, then I'll try to systematically document which chips work and which don't.

Whatever, I'd found that the latest WDC W65C02S8P seems to run on everything, as long as the hardware mods are done.

This page has some info:

http://anyplatform.net/media/guides/cpus/65xx%20Processor%20Data.txt

But other pages list even more changes.

2
arbee37•

There are 2 different 65C02s. Rockwell made one (and licensed it around) that has different new instructions, which aren't the ones the 65C816 also implemented, and that chip won't work in an Apple II.

The second is WDC's, and thats the one we all know and love and which the 65C816 is back-compatible with.

1
fontockOP•

Unfortunately it seems it's a lot more complicated.

Software wise there's the Rockwell R65C02, which is different to the "standard" 65C02 made by Rockwell, NCR, Synertek, Mitsubishi, Ricoh, and Sanyo, (different again are the GTE and the CSG versions).

Then there's the WDC versions which are different again.

But then Hardware wise there are different manufacturing processes (eg different switching thresholds), and different pin-outs.

And because different Apples used different families of logic chips, and different speed memory chips, there are odd combinations which will work on some, but not on others.

For example I have three different Apples, all of which refuse to ruin with different individual R65C02's. I even have a genuine Apple 65C02 which will run on some Apples, but not others.

I'm waiting for some more chips to arrive, then I'll try to systematically document which chips work and which don't.

Whatever, I'd found that the latest WDC W65C02S8P seems to run on everything, as long as the hardware mods are done.

This page has some info:

http://anyplatform.net/media/guides/cpus/65xx%20Processor%20Data.txt

But other pages list even more changes.

2