The pinouts for the Macintosh IIfx and LaserWriter IINTX SIMMs are the same and both have nearly identical SIMM requirements, but the Macintosh IIfx requires SIMMs rated at 80ns or faster, while the LaserWriter IINTX only requires RAM rated at 120ns.
Macintosh IIfx 1MB SIMMs will work in a LaserWriter IINTX, if they fit physically (see Note), but standard LaserWriter IINTX SIMMs will not work in the Macintosh IIfx because the RAM is too slow.
Overall, we recommend that you use Macintosh IIfx SIMMs in Macintosh IIfx systems and LaserWriter IINTX SIMMs in LaserWriter IINTX printers.
NOTE: The LaserWriter II chassis opening limits the height of SIMMs used on the LaserWriter IINTX logic board. We found that some 1MB SIMMs are too tall, and the LaserWriter IINTX logic board will not slide into the chassis when they are inserted.
Article Change History:
31 March 1994 - Reviewed for technical accuracy.
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