Adding External Mass Storage to Your System 6 Mac

In this final and long overdue post on System 6, we will look at adding external mass storage to your System 6 Mac, typically a crucial element in loading application software onto it. After all, you won’t get far with 800K floppies!

External Zip-100 AppleCD300e Larger Set of Floppies

There are several types of mass storage you could choose to add: external hard drives, removable drives, CD-ROM drives, tape storage and so on. All of these are supported by System 6 and are viable options. However, we are going to focus on the two of these that I believe offer the most versatility: the Iomega Zip drive and the CD-ROM drive. Both are still readily available today (if only on eBay). The CD-ROM drive offers a standard media format that a great many programs are distributed on, and the Zip drive offers 100 MB of read/write storage – fundamentally a “super floppy” (this WAS part of the marketing literature for it, way back when!).

I am going to approach this article in the same way as I approached the work: I started with the Iomega Zip drive and then added the CD-ROM afterwards.

External Zip-100

You will of course need both hardware and software to accomplish mass storage for your System 6 Mac. The software of course is freely available on the web, but the hardware will set you back a few pennies. For System 6 Macs, you will want to restrict yourself to SCSI-interfaced Zip 100 drives, and similarly, SCSI-interfaced external CD-ROM drives. As of this writing, SCSI Zip 100 drives are still in abundant supply on eBay, running anywhere from $50 to $100 depending on the seller and the condition of the drive. For the CD-ROM drive, I would attempt to purchase an Apple CD 300 drive, for the simple reason that the drivers are easy to get and are known to be compatible with System 6. You can of course chose different hardware, but you will need to ensure that you also find System 6 compatible software for your drive.

From a software perspective you will need the Iomega Zip driver, v4.2.This can be picked up at Unfortunately, it is not yet out on Happy Macs Gopher site. I have a whole System 6 section that has yet to be loaded! For the CD-ROM driver, you will need Apple CD-ROM Software, v5.3.1. This can be found at the Mac Driver Museum, By the way, you can also get the v4.2 Zip driver here, so this COULD be your one-stop-shop.

Alright, with the preliminaries out of the way, lets get started! For all of this work, I used my (by now) trusty Mac IIsi, running System 6.0.8.


I started by connecting up my external SCSI Zip 100 drive and restarting the machine, just to establish that nothing happens until the driver is loaded. Sure enough, nothing happened! Zip disks, when popped into the drive, were roundly ignored by my Mac. So far, so good. Now I copied the Zip 4.2 driver (a single file) into the system folder and restarted. The restart was clean and Zip disks, when inserted into the drive, now popped up on the desktop as they should. In this case, I inserted a disk labeled System6Exchange, and you can see it mounted on the desktop image below. Well… that was too easy!

ZIP Mounted

… and it stayed that way. Using Iomega Zip drives with your System 6 Mac is incredibly simple. Just connect the drive, add the driver to the System folder, restart, and all is well. This is software the way software should be! Try doing this with a Windows 3.1 PC of the day! It would take days of fiddling to get this right, starting with the nearly Herculean task of getting a SCSI card into the system and running. Take it from me, System 6 Macs were way, way easier to work with than their PC counterparts. I have experienced this from both sides. I was a PC user at the time, and it was a nightmare to add new hardware to a PC. Remember the old ad? Macintoshes were “plug and play”, while PCs were “plug and pray”? 🙂 It wasn’t just clever advertising – it was TRUE!

So now you can read Zip 100 disks on your System 6 Mac. Great! But how do you load anything interesting onto those disks so that you can use them to transfer software and other data onto the Mac? Zip 100 drives are largely a relic of history now, but happily, historical relics remain in abundant supply on eBay. Even given that however, the long and the short of it is that you will need another vintage Mac to write anything useful onto those Zip 100 drives

There are two approaches here. For the first one, you can physically transfer your existing Zip 100 drive to another vintage Mac that supports a SCSI termination, and then load a Zip disk from there. In my case, I have another SCSI Zip drive on my Power Macintosh 7300/200, and I used it to load software and images on to a Zip 100 disk, which I then loaded into the Zip drive on my System 6 Mac. This let me load up my Mac IIsi with software, up to 100 MB at a time.

As a second approach, you can purchase a USB-interfaced Zip 100 drive and use it to load a Zip disk from a USB equipped Mac. I do this as well from time to time. The very PowerMac G5 upon which I am composing this post has a USB Zip 100 attached to it and I use it to load Zip disks routinely. You can see this setup below:

Powermac G5 Dual w Zip

I do not believe that you could plug a USB Zip 100 into a modern Mac and have it work. If any reader tries this and it works, please let me know. My limited work in this area, posted to this blog on July 1, 2013 in the article “Mac OS Standard is Not So Standard” suggests that you cannot write Zip disks in the Mac OS Standard disk format required by System 6 with a Mac running anything beyond Mac OS X 10.4 Tiger. So, I am pretty sure that you will need a vintage Mac to implement even this second approach. If you should find differently, please do let us know!

OK! Onto getting a CD-ROM up and running on System 6. I had quite a bit more trouble with this one, although the outcome was eventually successful. To save you quite a bit of frustration, let me cut to the chase. Before you start down the CD-ROM trail with System 6, you need to add an obscure extension called Desktop Manager to your System folder. This was the key breakthrough in my efforts to get CD-ROMs running on my Mac IIsi. The ever-helpful Macintosh Orchard site, from which you can download Desktop Manager, describes it thus:

“Prevents desktop rebuilds when swapping back and forth with System 7. Allows desktop mounting of CD-ROM. Needed for some file serving apps. Part of AppleShare File Server 2.0.1.”

The key part is that second sentence of course … allows desktop mounting of CD-ROM. After I tracked down and installed Desktop Manager, the rest of was easy.

I am not sure if both of these are needed, but since this is how I approached the task, I will report both. I first loaded Apple CD Setup 3.2, and then when that did not resolve the issue, I loaded Apple CD-ROM 5.3.1.My guess is that all that is really needed is Apple CD-ROM 5.3.1. This is available from the Mac Driver Museum mentioned above.

With Desktop Manager and Apple CD-ROM 5.3.1 loaded, plus a restart, CD-ROMs inserted into my Apple CD 300 drive spin up nicely, and after a disconcertingly long pause, mount cleanly on the desktop. In the screenshot below, you can see both the Zip 100 disk from the steps above and the CD from this step mounted on the desktop.

ZIP and CD-ROM Mounted

When it was all said and done, and with the Zip disk and the CD-ROM together in an external SCSI chain, my Mac IIsi installation looks like this:

Mac IIsi w Zip and CD

Here is an additional “hack” for those interested in trying it. If you have a bootable CD-ROM (in my case a Mac OS 7.6.1 CD), there is a device driver located on track 0 of the disk. This is part of the requirement for being a bootable CD-ROM. If you insert such a CD-ROM into the drive and let it spin up BEFORE you power on your Mac, the Mac’s ROM-based SCSI manager will read and load the device driver from track 0, giving you “software-free” access to the CD-ROM drive. I tried this early in my work above, and after the bootable Mac OS 7.6.1 CD I used had mounted on the desktop, I ejected it and put a different, non-bootable CD into the drive. With the device driver from the original CD still loaded, my Mac went ahead and obligingly mounted the second CD on the desktop too! So, in the worst case, you can “seed” your CD-ROM session with the driver from a bootable CD, and then switch that out for the CD you are trying to work with. Your mileage may vary, but it worked for me.

… and that’s that! You now have both Zip-100 and CD-ROM mass storage up and running on your System 6 Mac. Load away to your heart’s content!



Getting Software Onto A System 6 Mac

Your “new” System 6 Macintosh has finally arrived, and you have either loaded it with System 6 yourself, or more likely than not, it has arrived preloaded with it.


Now you are eager to start loading your own favorite software onto it, but right away you are faced with a serious disconnect.

The Problem:

Today’s world speaks CDs, DVDs and websites, but your System 6 Mac speaks floppies, and only floppies, at least when it first arrives …and not just any floppies …typically it will arrive equipped with the long forgotten dual-sided 800K floppy. Given the complete technical discontinuity between how you can deliver software to your new Mac and how it is able to receive it, you clearly have a problem. Getting software onto your new System 6 Mac may not be as easy as it might have seemed!

To compound this problem, a lot of the software that can be downloaded from the web for System 6 arrives as .dsk, .img or .image floppy disk image files. More often than not, these have to be “burned” to an actual floppy in order to be installed, and of course, on more occasions than not, these floppy images are going to be for 800K floppies.

Box of 800K Floppies (398x356)

Of course, you don’t have 800K floppies, nor the floppy drive to load them with. Your new Mac has an 800K floppy drive of course, but you have to load the disks you are going to feed into it. How will you do this? There are lots of interesting solutions to this problem, but a chicken and egg conundrum quickly emerges. Many of these solutions are enabled by some of the very software that you are trying to load onto your Mac, but to get that software onto your System 6 Mac, you need the solutions they implement already in place! …sort of a Catch-22!

Available Tools to Solve the Problem With:

So, what tools do you have available to bridge this technology chasm?

800K Floppy: The troublesome 800K floppy is one such tool. If you have access to another vintage Mac that supports this format, and is already loaded with some of the software you need, you have a viable avenue. Alternately, if you have access to a vintage Mac that has a dedicated external floppy port, you can surf over to eBay and purchase one of these drives, and a box of the 800K floppies to go with it. Both are readily available on eBay, and for a reasonable price. Then you can load software onto 800K floppies and walk them over to your new System 6 Mac – SneakerNet!

SneakerNet III

Networking: Networking is another tool. If you can network your new System 6 Mac to one or more other vintage Macs that you may have, you can transfer the software you want to load via AppleTalk. Of course this means that you need to load Apple’s Network Software Installer (NSI) v1.4.5 (the last version that was compatible with System 6) and then MacTCP onto your new System 6 Mac.

At this point, I am sure that I don’t need to say that the floppy drive on your new Mac is the only way to accomplish this, and so you need to purchase floppies with these components on them. NSI floppies show up periodically on eBay, again at a reasonable price, and so this is an option. Alternately, perhaps you have an NSI floppy lying around from days gone by. MacTCP is a bit more troublesome, since while it is readily available on the web, it does not show up by itself on eBay.


CiderPress: Another possible tool is to use a Windows XP PC (yes, a PC, not a Mac) to write the floppies you need. There is a WinXP program called CiderPress that will do this, but it will only work for 1.4MB floppies, since no WinXP PC will have the hardware to write the long obsolete 800K format. You CAN write 800K floppy images onto 1.4MB floppies using CiderPress, but I have not had much luck with the results. I am told that it works – it just hasn’t for me. Your mileage may vary!

CiderPress 01

Zip-100 Drive: By far the simplest tool is the once ubiquitous Zip-100 drive and disks. If you can support a Zip-100 drive on any other computer you have access to, Mac or PC, and you have an external SCSI Zip-100 drive that you can attach to the SCSI port on your new System 6 Mac (all of them will have such a port), you have a great means for transferring software in volume.

External Zip-100

It is not quite that simple of course. You need to load the Iomega Zip Driver v4.2 (NOT to be confused with the IomegaWare package of the same or similar number – these two sets of software do not have harmonized version numbering!) onto your new System 6 Mac, and so once again you need to get that onto a floppy disk. Happily, this driver is very small and can be transferred easily this way, ONCE you have a way of writing HFS floppies. In this case, it can be 800K or the more available 1.4MB floppy – the driver is small enough that it doesn’t really matter.

There is one big catch here though if you are going to use a Mac to accomplish the transfer of files onto the Zip disk. As I reported in a very early post in this blog, Mac OS Standard is Not So Standard After All, you will need a Mac running Mac OS X 10.5.8 Leopard, or lower to load the Zip disks. Higher versions of Mac OS X will read Zip disks in HFS format, but they will not write them in this format. So, you are back to needing a classic Mac again, or a newer G4/G5 machine running a version of Mac OS X up to but not higher than 10.5.8 Leopard.

Linux! There is one more tool/approach I will mention, but I will not delve into it in any detail. You CAN use Linux to read and write HFS formatted floppies and Zip disks, and to do the equivalent of making DiskCopy sector-by-sector copies of the same.


However, I am guessing that the average reader of this blog will not also have an interest in Linux systems, nor have one or more of them just lying around and waiting to help in the accomplishment of the above. If you do however, and you want to try this route, you will need to install the HFS file system into your Linux distribution, and also become familiar with the incredibly flexible “dd” command. Linux can be challenging though – good luck!

Combining the Tools to Load Your System 6 Mac:

Setting Linux aside, lets look at how we can put the other tools together in various configurations in order to accomplish the desired result of getting software onto your new System 6 Macintosh.

Configuration 1: You have another vintage Mac whose floppy drive supports the 800K format. In this case, you can transfer software in painfully small 800K parcels until you get your new System 6 Mac up to where you want it. As mentioned above, this method is often referred to as SneakerNet, for the hopefully obvious reasons.

Configuration 2: You have the vintage Mac above, which supports 800K floppies, AND you have a one or more external Zip drives. In this case, you can use that 800K floppy just once, to transfer Iomega’s Zip Driver v4.2 onto your new System 6 Mac and then restart. From then on, you can transfer massive numbers of files (relative to the standard of the day) via 100MB Zip disks. This is SneakerNet on steroids!

Configuration 3: You have Configuration 2 AND you have a G4/G5 machine running Mac OS X Tiger or Leopard. In this case, you can use the above vintage Mac to get the Zip driver onto your System 6 Mac and then use Zip disks thereafter, loading them from the external Zip drive connected to your G4/G5.

This was my situation with my new Macintosh IIsi. I had a Quadra 840AV (running Mac OS 8.1) that supported both 1.4MB and 800K floppy formats. I used it to put the Iomega Zip driver onto an 800K floppy, used that floppy to load the driver onto the Macintosh IIsi, and then was able to switch to Zip disks for the rest of my software loading, with those Zip disks being loaded from my PowerMac G5.

Configuration 4: You have another vintage Mac that you can network your System 6 Mac to. Now you just have to install System 6’s networking software and then you can use AppleShare to transfer files from your other vintage Mac. To enable this approach, you need to find Apple’s Network Software Installer (NSI) v1.4.5 … on a floppy unfortunately… and install it on your System 6 Mac. You may also need to install MacTCP as well, if you are planning on using Ethernet networking. From there on, you can network to your other vintage Mac (using either LocalTalk or EtherTalk, as you wish) and you are off to the races.

Apple NSI

Now of course, getting NSI onto a floppy can be easy, or it can be tough. It can be easy if you have managed to gain access to an existing NSI floppy, perhaps because you have one from days past, or maybe one came with your new System 6 Mac, or you were lucky enough to be able to buy one on eBay (I took this last course). It can be hard if none of the above apply and you have to find a non Macintosh way to burn an NSI .image file onto a floppy. In this case, the Windows XP CiderPress program I mentioned above can come to your aid, provided you have a Windows XP machine to run it on, and the time and the patience to figure out how to accomplish your intended task via CiderPress’ hopelessly non-intuitive user interface.

Configuration 5: Nothing, Nada, Zero: You have no other classic Macs to help you out (and thus you need to burn 800K floppies via CiderPress or like utilities) AND to really complicate matters, your new System 6 Macintosh supports ONLY 800K floppies. In this case, you are in a real pickle, since any Windows XP machines that you might run CiderPress on will only be able to support 1.4MB floppies. Your only option at this point may be to fall back to buying some premade floppies from web sites such as, which specialize in solving this very problem.

What About Using A CD-ROM?

Wait a minute, you may be thinking to yourself… what about using a CD-ROM to accomplish the loading of software onto the new System 6 machine?


Well, that is a good question, but the idea is fraught with just a few perils:

1/ The CD-ROM was not yet widely available during the reign of System 6, and so you will find very little (if any) System 6 software available via this media.

2/ You also will not find any System 6 capable machines that come with a built in CD-ROM drive. CD-ROMs simply were not part of the typical hardware lineup of the day. Happily, Apple (and others) did eventually produce external SCSI CD-ROMs that can be attached to your System 6 system, but this doesn’t really get you too far ahead – see the next peril.

3/ If you DO have an external SCSI CD-ROM that you can attach to your system, you still need to load the Apple CD-ROM support software onto the System 6 machine before it will read the CD-ROMs in question. Unfortunately, this puts you back to the problems and solutions above.

4/ Finally, to use a CD-ROM to do general-purpose software loading, you are going to have to load that software onto a CD-ROM, and thus will need to be familiar with burning CD-ROM ISO images. This is a whole separate topic that this post will not go into at this point.

As I said, just a few perils… and enough of them that I did not even consider this as a viable avenue.

Tools, Problems and Perils – Sheesh! What is the Best Approach?

SO… how do you best approach the problem of loading software onto your new System 6 Mac? Well, as I said in my last post on Getting Started With System 6, if you are new to the world of vintage Macs, I would not recommend System 6 as the best place to start. Start with a later version (I recommend Mac OS 8.1 specifically), and a matching classic Mac to run it on, and then backtrack to System 6 once you have that environment running cleanly. There are large numbers of such machines available even today on eBay, making this a very sensible and economical option.

Why a later Mac and Mac OS 8.1? The reasons are many, but the key ones are that later Macs will come with a built in CD-ROM drive and full software support for it, preloaded networking, and often, the Iomega support already included. Mac OS 8.1 is a particularly good choice because it straddles the gap between earlier versions of AppleTalk over EtherTalk and the later versions of AppleTalk over IP, making it a perfect bridge machine between the older and newer vintage Mac worlds.

Of course it doesn’t hurt that Mac OS 8.1 is also the final version of Mac OS that will run on 68K Macs, making it incredibly flexible irrespective of the machine you chose. It also doesn’t hurt that Mac OS 8.1 is fairly “modern” version of Mac OS, overcoming many of the “peculiarities” of its earlier predecessors.


So, there you have it. As I said initially, getting software onto your new System 6 Mac can be really easy, or it can be really tough. I recommend attacking this problem from the vantage point of having an existing classic Mac with 800K floppy support already in place. This gives you the most direct set of approaches to accomplish the task at hand. Good luck!

This post composed on a PowerMac G5 running Mac OS X 10.4 Tiger


System 6 Software Links Added to Recommended Links Page

As promised in my last post, I have now updated the Recommended Links page with a set of known good links to pages from which you can download System 6 compatible software.


Some of these pages are devoted exclusively to System 6, but some are focused on Mac OS in general, thus System 6 and later releases. However, the collection represents the full set of sources I have used so far for the software I have running on my System 6 Macs.

If you are reading this post and are aware of other sources of System 6 software, please take a moment and comment on this post to that effect. I will update the links page as quickly thereafter as possible.

I have also had to remove a small number of now dead links from the Recommended Links page. Regrettably, some great sites have now disappeared, and they will be missed.

Check out the new links. There is still a vibrant community of users interested in System 6. Perhaps you will become one of them!