From: Gerrit Heitsch <>
Date: Sun, 24 Jul 2016 14:22:07 +0200
Message-ID: <>
On 07/24/2016 01:42 PM, Segher Boessenkool wrote:
> On Sun, Jul 24, 2016 at 12:58:36PM +0200, Gerrit Heitsch wrote:
>>>> Depends... On the later Chips, MOS included a number to the right of the
>>>> datecode. From what we've been able to determine, if it starts with a
>>>> '1', the Chip is NMOS and if it starts with a '2', the chip is HMOS-II.
>>>> The other numbers are the revision and match the R-number if it's
>>>> present on the chip. I have a few 6510 from after 1986 that have a '16'
>>>> printed there, so they would be NMOS which would suggest the 6510T also
>>>> to be NMOS since it's from 1984.
>>> Great info, thanks!
>> I looked through my collection and found a GARY (5719) where this number
>> is a '42' and a BUSRTER (5721) with a '40', suggesting the '4' stands
>> for CMOS. I also have a  C64-ROM with a '31', but no idea what the '3'
>> could mean. The '4510R3' from the C65 has a '53'... So what could the
>> '5' mean?
> Some more info, from c64 chips...
> Some 6502AD are marked "1D".

I assume that the D is hex and means '13'. So that would be a 6502 in 
NMOS Rev. 13.

> Some roms are marked "01".

I have Images of 6522 marked '03'.

> All 1986 chips I found have no such marking, all 1987 chips do.  So
> somewhere around this was introduced.

The oldest Chips with these markings are a pair of 6522 with a datecode 
of '4086'. They are marked '10'. The next oldest one is a 6502A marked 
'1D' with a datecode of '4486'.


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Received on 2016-07-24 13:00:02

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