Apple Mac IIfx – Rare 64-pin RAM SIMMs by "Doug Brown" – 16Mb x 4 - Computer - With replacement box

>> For the fortunate Mac IIfx owner

Rare 64-pin RAM SIMMs – tested, working, and increasingly unobtainable!

If you are reading this, you are already part of a very small and privileged group: owners of the legendary Macintosh IIfx, the true Rolls-Royce of classic Macs. What I am offering here is something that perfectly matches that status.

These 64-pin RAM SIMMs were purchased by me roughly ten years ago, at a time when they were already difficult to source. Today, they have become virtually impossible to find. Even more importantly, "Doug Brown" no longer produces or sells these modules, which makes them highly sought-after and genuinely exceptional within the vintage Macintosh community.

Recently tested and fully working — ready to be installed and enjoyed.

// Why these SIMMs are so special

– The Mac IIfx requires very specific 64-pin memory modules.
– These modules were not used in any other Macintosh model (with the sole exception of the LaserWriter IIfx).
Unlike the common 30-pin SIMMs of the era, these are 8-bit modules capable of simultaneous read and write operations, delivering a real performance advantage.
– Apple officially limited the IIfx to 1 MB or 4 MB modules, and even back then they were expensive and exclusive.
– Today, original and compatible modules are nearly impossible to obtain.

As knowledgeable enthusiasts will appreciate, the Mac IIfx — much like the SE/30 — supports 16 MB SIMMs, allowing for a maximum of 128 MB of RAM when fully populated. This hidden capability is precisely why these modules have become so desirable.

// Designed by a respected name in the community

These SIMMs are made by Doug Brown, a highly regarded hardware designer and vintage Macintosh enthusiast.

– Creator of the ROM-inator II).
– Well-known for programmable ROM SIMMs and 68k Macintosh tools
– Renowned for high-quality, performance-focused, and reliable
– His work has formed the foundation of several landmark projects in the vintage Mac world

The fact that Doug no longer brings these modules to market significantly increases their rarity and collector appeal.

// In summary
– Purchased ~10 years ago
– Extremely rare today
– Recently tested and fully functional
– Made by Doug Brown
– Perfect for taking a Mac IIfx to its full potential

This is not just memory.
This is a piece of Macintosh history — offered to someone who truly understands what makes the Mac IIfx so special.

For the collector.
For the enthusiast.
For the fortunate Mac IIfx owner.

Despite extensive searching, I have not been able to find these RAM SIMMs offered on any other websites, further underscoring just how rare and exclusive they have become.