BlueSCSI: The ultimate classic Mac hard drive replacement

It finally happened… the Macintosh Classic got a storage upgrade.

A couple weeks ago my 1991 Macintosh Classic gave me a bit of a scare when its factory-original 40 megabyte Quantum ProDrive LPS hard drive failed to spin up as usual. While there were no super important documents on the drive, it did have its original System 6.0.7 install from the factory and I was using it for storing some personal files. (When I purchased the computer, it also came with the original owner’s files. I have since erased those files to free up space for my own use, and to protect their privacy. They had modified dates ranging from 1992-late 2001, indicating the machine was in somewhat-regular use till then, which is a bit crazy to think about.)

Since I was using a System 7.1 volume via HD20 emulation on my FloppyEmu, I didn’t notice it until I couldn’t find the drive on the desktop β€” then realizing I couldn’t hear the drive spinning. I rebooted the machine to see if that would change anything, but I got the same result.

Thankfully, the drive spun up and acted as usual the following day. I immediately made a backup of the drive, starting with a rudimentary backup of my files followed with a complete copy of the drive with its System 6.0.7 installation. However, I could no longer rely on the drive to function β€” it was only chance that it’d spin up again.

Thus, the time for a solid-state storage upgrade had come.

It has been a couple years since I last seriously tinkered with my vintage Macs, mostly due to space concerns and having my attention on other things. However, the dismal state of the Kansas City Royals and miscellaneous stuff/stress drove me to find something else to occupy my time with. And I figured since I’ve had my Classic apart (at least enough to remove the logic board) before here, it shouldn’t be a problem β€” even with fewer space.

My time away became evident when I started looking at drive replacements. The BlueSCSI was just starting to really hit the vintage computing scene around the time I started my hiatus, and the FloppyEmu and SCSI-2-SD were the main drive replacement solutions then. My FloppyEmu works fabulously, and is an important part of my collection and using these computers regularly. (In fact, this post β€” and many others β€” written on my vintage Macintosh computers would not be here on the Internet without the FloppyEmu.) However, I wanted an internal solution/replacement that was more permanent.

I was shocked to find that the SCSI-2-SD had been discontinued, with its creator (originally Inertial Computing, now Rabbit Hole Computing?) focusing on the improved ZuluSCSI. So my choices were the ZuluSCSI and the BlueSCSI.

There are many versions of both the ZuluSCSI and BlueSCSI. I’m not the most well versed in these two offerings, but according to the BlueSCSI introduction note the BlueSCSI is a “fork” of the ZuluSCSI project. Both are based around the Raspberry Pi RP2040.

I went with the BlueSCSI, partially because it was slightly cheaper (the ZuluSCSI RP2040 is $59, but the BlueSCSI v2 Pico was $35 β€” with a mounting bracket) and I already have a relationship with one of its creators. I purchased my Apple ImageWriter II from one of its primary creators β€” Eric Helgeson.

Shipping gripe

Before jumping into the BlueSCSI installation, mine did come slightly beat up.

My BlueSCSI came mailed in a blue bubble mailer that was received with multiple small holes torn into the front of it. Upon opening, the static shielding bag inside also had multiple holes in it with a couple pins still protruding from it. The pins were also fairly bent from normal abuse in the mail. Thankfully, I carefully removed the BlueSCSI from the bag and bent the pins as straight as possible. However, it still peeved me.

The BlueSCSI’s pins are seen protruding through the static shielding bag it was shipped in, and also punctured several holes in the bubble mailer. Notice how two of the three LED connector pins (bottom left) are bent, and the power jumper (upper left) is protruding through the bag.

Installation process

Installing the BlueSCSI is a fairly straight-forward process, as it is pretty much a drop-in replacement for the old mechanical drive. That, however, doesn’t mean I didn’t face any challenges during the process.

First was formatting the 8 GB SD Card I purchased for the project, followed by creating a disk image on the card for the Mac to work with. Instead of doing it in Terminal, I used Disk Jockey (by One Geek Army) on my M1 Mac mini to create the volume. The software makes it fairly fool-proof, which comes in handy for someone like me. Disk Jockey has presets that automatically names the disk image appropriately for the BlueSCSI, as filename conventions are important for images in the BlueSCSI world. DiskJockey also can produce a separate “ROM Drive” that contains a couple utilities.

A screenshot taken while creating the Classic’s disk image in Disk Jockey, a utility for easily creating images for use with vintage Macs. Another fun feature of it is the cool floppy drive eject sound effect after the image is created.

With the SD card ready to go, I was left with the task of opening the Classic to install the BlueSCSI itself. It was the first time I’ve cracked the Classic (or any of my Macs) open since spring 2021. The bucket did require some careful prying with a spudger-like tool to separate. (No worries β€” nothing that could cause damage.)

After needlessly removing the screws for the floppy drive, I realized that all I needed to do was remove two screws holding the hard drive carrier/enclosure to the floppy drive housing. Again my time away from the hobby has shown.

Removing the two screws, however, came at a cost. The bit for my cheap screwdriver kit falls out anytime you release pressure, and of course that happened a few times along the way. However, perhaps the most worrisome was the bit appeared to have fallen into the floppy drive after removing the right screw. I caught the screw, but the bit fell in.

After my bit detached itself again, falling into the case, I jostled the machine to get it out. Along with it, thankfully, came the bit from the mishap earlier.

The 1991 Macintosh Classic’s original 40 MB Quantum ProDrive LPS hard drive after being removed from the computer, still in the drive carrier. The drive is mounted in the computer with the circuit board facing up.

With the old Quantum ProDrive out, the BlueSCSI had to go in. I purchased my BlueSCSI with an optional 3D-printed bracket for securing it to the drive carrier. I haven’t worked a lot with 3D-printed plastics a lot before, but I was concerned about possibly overtightening the screws, cracking the bracket β€” rendering it useless.

The BlueSCSI’s included 3D-printed bracket for mounting inside the Classic.

I was also worried about possibly exposing the long metal pins found on the BlueSCSI metal to anything conductive, such as the CRT screen or drive carrier. Thankfully, I got the drive mounted in the drive carrier without snapping the bracket. Clearances were very small between the CRT and the BlueSCSI’s LED connectors and the power jumper, but appeared to be sufficient.

Clearance between pins on the BlueSCSI and the cathode ray tube of the Macintosh Classic. The power jumper appears to be possibly be touching the CRT, and there’s just an inch or two between the CRT and the LED pins.

I started running into problems, however, connecting the BlueSCSI. The power supply connector for the drive didn’t completely match the BlueSCSI’s power connector β€” at least not physically. A Google search revealed that connecting power to the drive isn’t necessary, as it can work on the 5-volt SCSI termination bus alone. So I took a chance and left it unplugged.

The more serious problem was with the 50-pin ribbon cable used to connect the BlueSCSI to the Mac’s logic board. Initially, with the BlueSCSI mounted facing upward, the ribbon cable would not fit in both connectors. There are no instructions for mounting the BlueSCSI or the bracket, and YouTube installation videos showed various other brackets found with various other BlueSCSI designs, so I wasn’t completely sure if I had it installed properly.

Out came the BlueSCSI again. I flipped it β€” this time with those long pins facing the metal drive carrier. When re-tightening the screws, I noticed a crack in the bracket. Eek! Thankfully, I got the screws tightened sufficiently and there is considerable clearance between the bottom of the drive carrier and any of the BlueSCSI pins.

The BlueSCSI flipped in the Macintosh Classic’s drive carrier.

With the BlueSCSI only connected to the logic board, I powered on the machine and crossed my fingers that the drive would power up and no magic smoke would escape.

No smoke came out, and the machine booted to the flashing disk icon. A good sign that I hadn’t made anything worse.

First impressions

With the FloppyEmu now connected to the Mac, I tried to install System 7.1 to the 120 MB volume on the BlueSCSI’s SD Card. Unfortunately, the 7.1 installer wasn’t finding the volume. It was, however, finding the “ROM Drive” the Disk Jockey software offers for use with the BlueSCSI. So we knew the Mac was communicating with the BlueSCSI and accessing the card.

From there I soft-rebooted the Mac, this time booting into the special System 6.0.3 installation found in the Classic’s ROM. (This can be accessed by holding Command+Option+X+O while the machine is booting, typically as its doing a memory check before looking for the OS.) The operating system found the blank 120 MB volume, which I subsequently formatted with HFS (Hierarchical File System) for use with the Mac.

This time, System 7.1 installer found the drive. And, eventually, the BlueSCSI had a successful System 7.1 installation.

With System 7.1 installed and the Classic functioning fine off the BlueSCSI alone, I loaded the aforementioned System 7.1 HD20 image on my FloppyEmu and started copying some files β€” many of which came from the Quantum ProDrive.

Screenshot of the desktop of the System 7.1 installation on the 1991 Macintosh Classic after getting my files copied over.
Contents of the special “ROM Disk” volume Disk Jockey created alongside my standard 120 MB volume.

The process of copying the files was fairly quick, which is the main benefit of having solid-state storage, like the BlueSCSI, over the old mechanical drives. Solid state media, including even the FloppyEmu, is far faster than the old mechanical drives of yesteryear.

There are multiple other advantages to the BlueSCSI and other solid state media: price, reliability, noise. Functional old mechanical drives, such as another Quantum ProDrive, are hard to find and expensive β€” and may not last that long after installation. Mechanical drives, even modern ones, have a very finite life. While not infinite, flash media β€” such as the SD card β€” will far, far outlast a mechanical drive from 30 or even five years ago.

I will miss the constant drone of the Quantum’s spindle motor, and the ticking sounds of it seeking and reading/writing to the drive. The sound is a special one, and something that takes me back to my childhood and when I first got into computers β€” when they were noisy with mechanical drives, large fans, and floppy or optical drives. However, the absence of the drive doesn’t make the Classic completely silent. You still have the constant hum of the fan.

However, all those advantages β€” quicker speed, lower cost and reliability and peace of mind β€” outweigh the novelty factor of a replacement mechanical drive. Now the Macintosh Classic has 21st century technology driving 20th century technology.

The BlueSCSI is an easy and cheap way to bring solid-state reliability and speed to your vintage Macintosh. However, it doesn’t just work with the Macintosh. It also works with Amigas, Ataris, Apple IIs, and even IBM’s PS/2 computers. (And probably the IBM PC/XT/AT with appropriate interface cards.) The installation process was fairly straight-forward, despite my challenges with mounting it. My only real criticisms are instructions could be more complete (for installation, specifically the included bracket) and the packing issue.

Update: May 8, 2023

Eric Helgeson responded to this article, apologizing for the shipping damage and clarifying some things.

  • Regarding shipping damage: Eric said this was the first time a board got so beat up in the mail; “It must have got really thrown around.” It was odd. Fortunately nothing was damaged as a result… sometimes even with decent packaging things still get damaged. (I’ve updated this post to be a little more forgiving, as it was unusual. My original post came off a little harsh.)
  • Regarding 68kMLA: The original version of this post mentioned that Helgeson was active on 68kMLA. He said that is most certainly NOT true, adding that he is instead active on Mastodon, TinkerDifferent and Discord. (Thanks for the mention, Eric. I’ve now joined the TinkerDifferent community, and look forward to getting insight on a couple other projects in the near future. On first glance, it seems to be a lot more lively and inclusive, and features all types of platforms β€” IBMs, Commodores, Tandys, Ataris, etc. β€” all in one place. I like it.)
  • Regarding BlueSCSI mounting: Eric said the board mounts upside down in SE (and Classic). A sturdier “PotatoFi” bracket is offered for sale with holes for all four screws. (Eric said he would send one to make up for the shipping issue.)
  • Regarding power supply: “Lastly the power connector is the same as all drive emulators, a berg or floppy connector. This is due to cost and space. You can pick up a berg to molex adapter for cheap, and I sell them on my store with purchase.”
  • Regarding attribution for BlueSCSI being a fork of ZuluSCSI: “The ‘according to AdaFruit’ article is just a copy/paste of my announcement page here:Β

Thanks for the email!

Written on a 1991 Macintosh Classic running System 7.1 using Microsoft Word 4.0.