2023-07-12 — updated 2024-01-31

The Motorola 68k processor line was used for Macintosh from the first 128k in 1984 to the last Quadra, Performa, and LC models were discontinued in 1996. There’s a ton of information on the web about 68k processors, but it is ubiquitously unsourced and often inaccurate.

Below is a chart of common processors with a focus on those used in Macs, using only what I could source from the original suppliers: Motorola, Freescale, NXP, Rochester Electronics, Thomson, and Atmel, excepting the product names which are approximated from believable product images.

Currently, this page focuses on 68030 and 68040 processors.

This is a best effort, cross-referencing multiple fragmented sources to provide as complete a picture as possible. More exact (but unsourced) information exists in some cases, which may be useful to provide additional data. I have refrained from using those sources here in order to provide only provably accurate information.

Notes and Processor List

Naming

Until 2004-03-22, primary source processors were printed with the Motorola logo. After this time Freescale was spun off from Motorola and started the process of transitioning branding. This transition was unbounded, so it is expected to see newer processors with Motorola branding.

There was no known transition to NXP or Rochester Electronics branding.

Sources

Motorola General Announcements #9722

Reading Chip Markings

Motorola chips generally contain 6-7 markings:

Logo
Product name and revision
Mask identifier
Serial number including manufacture date
Final assembly location
An unknown identifier which often corresponds to mask (package identifier or serial?)
An unknown identifier

For example, a 68040 has the first 6, and might look like:

M⃝ (logo)
This chip was made by Motorola.

XC68040RC25M (product name)
This is a 68040, XC-type (not fully qualified), in a PGA package at 25MHz with revision M.

02E31F (mask)
This is mask 02E31F (in documentation the leading digits are often dropped when referring to the mask).

QEKC9328B (serial)
This was made the 28th week of 1993. The 4-digit code in the middle indicates the date.

MALAYSIA (location)
Final assembly of this chip was in Malaysia. This does not indicate fab location.

523159-001 (unknown mask-related identifier)

68030RC

68030RC was the PGA “full” version with MMU, a co-processor was required for FPU. Used in a very wide variety of Macs from 1988 to 1995.

Sorted by approximate introduction, where not known, by mask.

Product	Mask	Revision	Fab	Geometry	Introduced	Cancelled
`XC68030RCxx*`	B47B	0	APRDL - Austin, TX	1.35µm	?	< 1995
`XC68030RCxx*`	3B47B	C	APRDL - Austin, TX	1.35µm	?	< 1995
`XC68030RCxxA*`	1B56P	D	APRDL - Austin, TX	1.35µm	?	< 1995
`XC68030RCxxB*`	B67R	I	MOS8 - Austin, TX	1.2µm	?	< 1995
`MC68030RCxxB`	C43C	B	MOS8 - Austin, TX	1.2µm	< 1993	< 1995
`??68030RCxx?`	C48A	G	APRDL - Austin, TX	1.2µm	?	< 1995
`MC68030RCxxB`	C74N	B	MOS8 - Austin, TX	1.0µm	?	< 2012
`??68030RCxxB`	D62C	B	Tohoku - Sendai, Japan	1.2µm	?	< 1995
`MC68030RCxxB`	D66C	B	Tohoku - Sendai, Japan	1.0µm	?	< 2002
`MC68030RCxxC`	F91C	C	Tohoku - Sendai, Japan	0.8µm	1995-05-24	< 2002
`MC68030RCxxC`	G40W	C	MOS8 - Austin, TX	0.8µm	1996-11-13	2012-05-31

Notes

“?” in the product represent unknown data.
“xx” in the product represents listed speed, as this varies.
“*” in the product represents unclear revision suffixes – suffixes do not always align with the Motorola listed Revision – these are guessed based on CPU-World images listed in sources below.
“<” indicates a mask was introduced or cancelled before the listed time, but an exact date is unsourced.

Markings

On approximately 2000-08-13, 68030RC markings were changed from ink to laser printing.

Sources

68040RC

68040RC was the PGA “full” version with MMU and FPU. Used in a wide variety of Macs from 1991 to 1996.

Sorted by approximate introduction, where not known, by mask.

Product	Mask	Revision	Fab	Geometry	Introduced	Cancelled
`XC68040RCxx`	D43B	B	MOS8 - Austin, TX	0.8µm	?	< 1995
`XC68040RCxx`	4D50D	A	MOS8 - Austin, TX	0.8µm	?	< 1995
`XC68040RCxxB*`	9D50D	B	MOS8 - Austin, TX	0.8µm	?	< 1995
`XC68040RCxxE*`	5D98D	E	MOS8 - Austin, TX	0.8µm	?	< 1995
`XC68040RCxxE*`	7D98D	E	MOS8 - Austin, TX	0.8µm	?	< 1995
`XC68040RCxx`	E26A	?	?	?	H2 1992	?
`XC68040RCxxM`	OE31F	M	MOS11 - Oak Hill, TX	0.65µm	?	Q3 1995
`XC68040RCxxM`	2E31F	M	MOS11 - Oak Hill, TX	0.65µm	?	Q3 1995
`MC68040RCxx`	2E42K		MOS11 - Oak Hill, TX	0.65µm	Q3 1995	2000
`MC68040RCxxA`	K63H	A	Tohoku - Sendai, Japan	0.57µm	2000	2002-11
`MC68040RCxxA`	L88M	A	MOS11 - Oak Hill, TX	0.57µm	2002-11	2015-11-21

Notes

“?” in the product represent unknown data.
“xx” in the product represents listed speed, as this varies.
“*” in the product represents unclear revision suffixes – suffixes do not always align with the Motorola listed Revision – these are guessed based on CPU-World images listed in sources below.
“<” indicates a mask was introduced or cancelled before the listed time, but an exact date is unsourced.

Additionally, these sources/clones were produced:

Thomson-CSF TS68040 - Military grade version to MIL-STD-883 spec
Atmel TS68040 (possibly a rebrand of the Thomson)

They are not covered further in this document as information is significantly more sparse.