Macintosh SE
The Macintosh SE was one of the longest-lived compact Macs, both in production and in steady refinement. Instead of handing the baton directly to the SE/30, it remained in the lineup as a “core model” until the Classic series arrived, which made its long run inevitable. The SE shared the same chassis and analog board as the SE/30, and compared to the early 128K and 512K, it was far more reliable—well-suited for heavy office use. The growing popularity of internal hard drives also boosted its reputation, freeing users from dependence on floppies. In the business market especially, that was a huge win.
Another reason for its durability was the use of axial electrolytic capacitors throughout, which had a much longer lifespan and rarely leaked. In fact, this is one of the key reasons why more SE units have survived compared to SE/30s. Early SEs even used axial through-hole PRAM batteries, which never caused the dreaded “battery bomb.” Later SE FDHD (SE 1/20 and 1/40) revisions, however, did adopt the same coin cells as the SE/30—so you might still encounter the occasional bombed-out board.
Recommended Hardware Mods
Expanding to the Maximum 4 MB of RAM
Depending on the revision of the logic board, memory expansion worked a little differently. The earliest logic boards required clipping resistors to trick the system into recognizing more RAM. Later revisions simply let you move a set of jumper pins. In earliest logic board, you’d find R35 and R36 marked “RAM SIZE” near the SIMM slots; cutting or reconfiguring them enabled the upgrade.
Even so, in my experience, almost every SE I’ve ever come across already had the full 4 MB installed. Finding one without the maximum RAM is pretty rare.
Upgrading an Early SE to FDHD
Since the SE was produced for so long, its logic boards went through several minor changes, but functionality remained largely the same. The only major upgrade was support for the 1.4 MB SuperDrive (Learn more)
To make that work, you need to swap the ROMs(342-0701 and 342-0702) and replace the floppy controller with a DIP28 SWIM chip. The SWIM (in PLCC44 package) was used in many later Macs, so if you ever plan to toss out a battery-bombed board, check for a salvageable SWIM before scrapping it...
With a Super Wh-IWM Swapper, you can even adapt the PLCC44 SWIM into a DIP28 socket.
As for the ROMs, two M27C1001 EPROMs will do the trick, though some pin re-routing is required for compatibility. Once installed, your SE can fully support the SuperDrive just like the later FDHD models.
Replacing the Floppy Drive with a Later Model
Everyone knows the stock SE floppy drives eventually fail due to broken eject gears. We manufacture replacement gears called Tune-O-Gear, but even after repair, you’ll sometimes find the heads are too weak to reliably read disks. In that case, you can actually swap in a later-generation floppy drive with a shuttered slot. They’re not a perfect fit—the manual eject hole is in a different spot, and the bezel alignment is a bit off—but it works.
To make it fit, you’ll need to add spacer on the top and mount it with double-sided tape instead of screws. I’ve designed STL files for the spacers, so you can download and 3D-print your own for a cleaner install.
When attaching the floppy drive with double-sided tape, please note that the entire surface will protrude about 3 mm from the housing.
BlueSCSI V2
The SE works beautifully with BlueSCSI V2, whether you use the desktop or DB25 external version. The sweet spot is System 6.0.8—it runs fast and smooth. Although it's not my project, I think the mount on the back is a good idea too.
BlueSCSI has some really useful little riser cards. If you’re running the V1 Desktop, you can drop in a SCSI-Rider TYPE-A, and for the V2, you can pop the SCSI-Rider TYPE-B (DB25) out of its shell and use the SCSI-Rider TYPE-B to mount it internally. Super handy if you want a clean setup.
For my own testing, I usually reach for the SCSI-Rider2. It works perfectly with the BlueSCSI V2 Desktop as-is, no extra fuss required. *There are also DB25 model that allow you to daisy chain DB25s directly.
When I first became the only BlueSCSI distributor in Asia, I was over the moon. I got so excited that I ended up designing a whole bunch of accessories for it. Looking back, that was one of the most fun creative bursts I’ve had in this hobby!
Plenty of Accelerator Options
One of the most exciting parts of the SE is its upgrade ecosystem. For example, the open-source Micromac Performer SE/Plus/Classic clone (reverse engineered by Bolle, also featured in my Mac Plus write-up) is still accessible today. Since it fits into the PDS slot, you don’t need to modify the logic board. Most accelerators disable virtual memory, but they usually include their own VM solutions, so it’s rarely a problem. The Performer SE/PL/CL supports Micromac’s excellent original driver too.
Unlike the Plus, the SE’s power supply is strong enough to handle accelerators without issue, so the stock PSU is perfectly fine. Many other accelerators were sold back in the day, and with luck, you can still find them floating around on eBay.
One of my luckiest finds was an SE that wouldn’t power its display. I swapped a bad transistor on the neck board, and the screen sprang to life—only to reveal a giant accelerator card inside! I thought I’d struck gold… but fate balanced things out when I later ended up buying three battery-bombed Macs in a row...lmao
Logic Board and Analog Board Replacement
These fall more into the category of repairs than upgrades. My friend Kai Robinson had his SE logic board destroyed by a battery leak, which led him to reverse-engineer and successfully build a clone of the SE logic board called SE Reloaded. Since the SE uses fairly simple components, assembly is relatively straightforward. In particular, because there are no surface-mount parts, even those without advanced technical skills can put one together with ease.
It’s not just boards—clear SE cases are now available from MacEffects. Pairing one of those with a fresh analog board makes the whole machine look stunning. We’ve also released my own reverse-engineered boards "SE Analog Board Resurrections"for sale.
If you’d like to test a logic board outside the chassis, using an extension cable makes the process much easier. You can even repurpose an ATX power supply extension cable for this. For those who prefer an even simpler solution, I also produce and sell a dedicated Extension Power Cable designed specifically for this purpose.
If someone were to ask me what kind of model the SE is ... I might have to answer this way: Among all the compact Mac models you could own, the SE is probably the only one that will still power on decades later without any issues. At least, that has been my own experience...
