Intel 8085 Date Codes

[Neon_WA]

Thought I would post info for collectors to work out date codes on Intel 8085 CPUs

For starters codes/plants on the bottom are for the die production.. not processor production
The standard Intel FPO code on the top is for the processor production date
I have put the copyright codes in time-line order for each 8085 type

8085 Varieties Die codes
no Copyright >> 4 digit code on bottom (YYWW) 19YY week WW
76 Copyright >> 4 digit code on bottom (YYWW) 19YY week WW

8085A Varieties Die codes
76 Copyright >> 4 digit code on bottom (YYWW) 19YY week WW
76 Copyright >> 7 character code (normally 6 numbers, 1 Alpha) on bottom (xYWWxxxx) 198Y week WW
76 77 Copyright >> 4 digit code on bottom (YYWW) 19YY week WW
77 Copyright >> 4 digit code on bottom (YYWW) 19YY week WW
76 80 Copyright >> 4 digit code on bottom (YYWW) 19YY week WW
80 Copyright >> 4 digit code on bottom (YYWW) 19YY week WW

8085A Varieties Production codes
76 Copyright >> FPO on top (PYWWxxxx) 198Y week WW
76 80 Copyright >> FPO on top (PYWWxxxx) 198Y week WW
80 Copyright >> FPO on top (PYWWxxxx) 198Y week WW

8085AH Varieties Die codes
80 Copyright >> 4 digit code on bottom (YYWW) 19YY week WW
76 80 Copyright >> 4 digit code on bottom (YYWW) 19YY week WW
76 80 Copyright >> 10 character code (1 Alpha, 7 numbers, 2 Alphas) on bottom (KxYWWxxxxx) 198Y week WW
1976 Copyright >> 4 digit code on bottom (YYWW) 19YY week WW
1976 Copyright >> 7 character code (normally 6 numbers, 1 Alpha) on bottom (xYWWxxxx) 19xY week WW
where if Y equal 9 then year is 1989 and
0 (1990), 1 (1991), 2 (1992), 3 (1993), 4 (1994), 5 (1995), 6 (1996), 7 (1997)
1976 Copyright >> 10 character code (1 Alpha, 7 numbers, 2 Alphas) on bottom (KxYWWxxxxx) 19xY week WW
where if Y equal 9 then year is 1989 and
0 (1990), 1 (1991), 2 (1992), 3 (1993), 4 (1994), 5 (1995), 6 (1996), 7 (1997)
1980 Copyright >> 4 digit code on bottom (YYWW) xxYY week WW
where if YY equal 96 then year is 1996
97 (1997), 98 (1998), 99 (1999), 00 (2000), 01 (2001), 02 (2002)
1980 Copyright >> 7 character code (normally 6 numbers, 1 Alpha) on bottom (xYWWxxxx) 19xY week WW
where if Y equal 6 then year is 1996 and
7 (1997), 8 (1998), 9 (1999), 0 (2000), 1 (2001), 2 (2002)
1980 Copyright >> 10 character code (1 Alpha 7 numbers, 2 Alphas) on bottom (KxYWWxxxxx) 19xY week WW
where if Y equal 6 then year is 1996 and
7 (1997), 8 (1998), 9 (1999), 0 (2000), 1 (2001), 2 (2002)

** some post 1993 production 8085 processors with 1976 or 1980 copyright may be blank on the bottom


8085AH Varieties Production codes
80 Copyright >> FPO on top (PYWWxxxx) 198Y week WW
76 80 Copyright >> FPO on top (PYWWxxxx) 198Y week WW
1976 Copyright >> FPO on top (PYWWxxxx) 19xY week WW
where if Y equal 9 then year is 1989 and
0 (1990), 1 (1991), 2 (1992), 3 (1993), 4 (1994), 5 (1995), 6 (1996), 7 (1997)
1980 Copyright >> FPO on top (PYWWxxxx) 19xY week WW
where if Y equal 7 then year is 1997 and
8 (1998), 9 (1999), 0 (2000), 1 (2001), 2 (2002)


these will cover about 99% of all 8085s. There are some alternative die codes which I need find more info to be able to break them down

[Neon_WA]

If you looking to purchase a pre FPO marked 8085 and you only have a top photo you can use the lot number as a guide to date

This applies to non A & A version 8085s
The lot number is made up of 4 numbers & 1 letter

Lot nnnnA >> up to about week 40 1977
Lot nnnnB >> from about week 40 1977 to about week 30 1978
Lot nnnnC >> from about week 30 1978 to about week 20 1979
Lot nnnnD >> from about week 20 1979 to about week 24 1980
Lot nDnnn >> from about week 24 1980 to about week 05 1981

for example lot number on Genna's P8085 is 1920B
I would expect the date code on the bottom to be around week 48-49 1977

[smithy]

Useful info Stu - thanks for compiling and posting

[Neon_WA]

working out dates especially later production seemed a miss & hit affair
but once I had enough data started to make sense

The one thing that surprised me in all the 8085 I documented I only came across one fake/remark.
Wasn't that obvious when looking at it.. but stood out when looking through my database

[Chiefish]

Hmm thats interesting, tell me why it is
The fonts? im going to dig it out and have a closer look at it now.
It has MALAY 8648 MBDD on the bottom of it.

[Neon_WA]

the font got me curious.. but the issue was using a '76 copyright
this was only used on 8085As

copyrights for 8085AH were '80, '76 '80, 1976 & 1980

could be genuine... just doesnt fit right

[Chiefish]

Well you know it is kind of sparlky when viewed with the naked eye, as you move it around under light it sparkles like it might have been polished by real fine sanding or somthing. None of my other d series seem to glisten like this one does.

[Neon_WA]

maybe Intel did it seeing it is X plant (US development facility) but why as not early production
if they were doing some redevelopment I would expect I plant (Malay Development plant)
things that fit
the word MALAY was used from mid 1988.. only 8085AH varieties
MBDD is only on MD8085AH varieties

here is list of all I have logged