Jon Thysell

Father. Engineer. Retro games. Ukuleles. Nerd.

Tag: scsi

Adventures in Macintosh restoration Part VII: System Experiments

In Part VI, I was able to install Mac OS 8.1 on my Power Macintosh 8600/200 using a SCSI2SD as the machine’s hard drive, and I was even able to get online. Now it’s time to play around with that setup.

The original plan

The plan for this machine has always been as a bridge machine between modern computers and older vintage Macs. It’s meant to give me some practice cleaning and restoring old parts, while also being as flexible and compatible as possible. It’s a utility machine.

In order to be the most compatible with the most software and the most hardware, I figured I’d need to install as many versions of Mac OS as possible. This machine officially supports System 7.5.5 through Mac OS 9.1, but rather than install the dozen of minor versions in-between, I thought one install per major version should be enough.

System 7

Let’s start with System 7. As far as I can remember, my childhood machines ran 7.0.1 or 7.1, older than what this new machine can handle. I remember the 7.5 series existing, and it’s possible that in the later years I ran it on the Centris 650 when I first got internet access.

System 7.5.5 is the earliest software this machine can run, and it’s the last version to support running 24-bit addressing (something the oldest programs need). The other contender for System 7 would be 7.6.1, which is considered mostly the same, except it’s got some PowerPC performance improvements that would apply to this machine.

In the end I actually chose 7.6.1 for this machine. It turns out the 24-bit support only applies to the 68k Macs, and this machine will never be able to run programs that need it. So 7.6.1 has the exact same compatibility as 7.5.5 but is just faster.

Beyond System 7

After System 7, we’re out of my personal experience. I may have used Mac OS 8 once or twice in high school, but I’ve never used Mac OS 9. I have no nostalgia for these systems, so the only requirement is to expand my access to software and hardware.

My initial plan was to pick just the latest in each line that I could run, Mac OS 8.6 and Mac OS 9.1. While I’m currently running 8.1, and having a little fun here and there playing some old games, as far as I can tell there’s no reason to run this version with newer ones available.

However, talking with people online, and it seems there are three camps when it comes to OS 8.

Camp one thinks System 7 was the pinnacle of Mac systems in terms of design and speed, and everything after that was bloat. They point out that the change from 7 to 8 was just to cut out the clone manufacturers, since they only had licenses to System 7. So 8 is really just a bunch of crap on top of 7.

Camp two thinks OS 8 is the pinnacle of Mac design, that 8 refined and filled in all of the gaps of 7. They say System 7 is too spartan for newer machines, and point out that 8 added better networking support and just as importantly, support for larger hard drives.

Camp three thinks OS 8 can be skipped entirely, thanks to Mac OS 9. Very little software lists OS 8 as a minimum, and even so, it’ll still run on OS 9. Same with hardware. Most things just work on 7 and above, or require 9, so unless you really like the style of 8, there’s no reason to use it if you can run 9.

I already planned on installing 9 as it gives me access to a variety of useful hardware upgrades on this machine such as USB and Firewire. So I decided to table the decision on OS 8 for now.

Let the experiments begin!

The first thing I did was backup the SD card with Mac OS 8.1. It doesn’t have anything particular that I care about, other than being a booting system. I re-setup the SCSI2SD with three virtual drives, then booted the 8.1 CD to use Drive Setup to format them.

I had already downloaded and burned CD images for a variety of versions: 7.5.5 and 7.6.1 specifically for this model, universal installs for 8.0, 8.5.1, and 8.6, and finally universal installs for 9.1 and 9.2.2.

I won’t go into all of the gory details here, but suffice it to say that I spent weeks installing and re-installing different OSes to the different virtual drives. I followed various suggestions online and took my own notes during the installation process of each. I ran benchmarks, browsed the web, and downloaded some apps and games to try out.

One win was getting an FTP server to run on the Mac, which meant I could more easily transfer files to it from a modern PC. That freed me up to download new software quickly on my PC, then upload the files to the Mac at my leisure. This gave me both an archive of downloads on the PC and saved me from having to browse the web on the Mac and deal with increased chance of download failures.

The other big win was installing Mac OS 9.2.2. Officially most machines can only run 9.1, because that was basically the last version of OS 9 meant to be run as an independent OS. By that point in time, Apple had switched over to OSX, but early versions still provided a “Classic Environment” compatibility layer that let those OSX users still run their old OS 9 apps.

Classic Environment still required a full copy of OS 9, and it got a few more stability and performance updates in the form of 9.2, 9.2.1, and 9.2.2. So installers exist for those versions, but of course they have protection measures in place to make sure you don’t just install them on older hardware.

However, thanks again to enterprising hackers, there’s a tool called os9helper that lets you trick the installer into working. And it worked!

The final plan

At the end of it all, I’d pretty much settled on a plan of only installing 7.6.1 and 9.2.2. I didn’t find any reason to keep 8 around, the installs sat dormant while I spent most of my time in 9.2.2. In fact, even keeping 7.6.1 around seemed to be “just-in-case”.

Anyway, this has been a pretty text-heavy post. I didn’t bother to take any pictures during all this software experimentation. Next time I’ll have more photos, as I dive into some hardware upgrades. So stay tuned for that in Part VIII!

/jon

Want to read from the beginning? Start at Part I.

Adventures in Macintosh restoration Part VI: Booting up and jacking in

In Part V, I was able to boot my Power Macintosh 8600/200 from a burned system CD. Now it’s time to get a system installed.

Hard drive options

At this point, I can boot the Mac OS 8.1 system CD, but I don’t have a hard drive to install it to. The first, most obvious answer, is to just get an old hard drive and install it.

However hard drives, especially mechanical ones, can have a rather short lifetime compared to other computer components. So while getting an “era-appropriate” hard drive is possible, it would be a gamble. Not to mention this computer originally shipped with a whopping 2GB drive – old hard drives come in sizes so small you can’t buy anything with that little storage any more.

So why can’t I just buy a new hard drive and install it? One word: SCSI.

SCSI is a old set of standards (cables, protocols, etc) for connecting computers to drives, and isn’t really used anymore for modern computers. Broadly speaking, vintage macs used SCSI and vintage PCs used IDE. These days there aren’t any new SCSI hard drives. It’s part of the reason I was so happy the CD-ROM worked – tracking down a replacement SCSI CD-ROM could have gotten pricey.

What does this mean for me? I already have an alternative, something I had bought in anticipation of this problem.

Hello SCSI2SD

The SCSI2SD is a device which simulates one or more SCSI drives using an SD card. Like the Floppy Emu, it was designed for people trying to keep older hardware up and running.

It’s not as easy to use as the Floppy Emu – that device is pretty plug and play – you copy your floppy disk images onto the SD card and use its built-in screen and controls to select which disk to load at runtime.

The SCSI2SD has a steeper learning curve and requires a little more setup. It connects to your PC via USB and comes with a configuration utility which you use to define the devices, or disks, that the SCSI2SD should report to the computer.

However, instead of having disk image files, the SCSI2SD requires you to map these drives directly to sectors on the SD card. So if you ever pop the SD card into your PC, it’ll tell you the disk is unformatted and ask you to format it. It also means you can’t easily add and remove files.

Basically, once you’ve configured it to your liking, it’s a great drop-in replacement for a missing hard drive, and you can backup your data by making a disk image of the entire SD card. Adding or extracting individual files is possible but requires a lot more work and tools.

Out of the box the SCSI2SD is configured for a single 2GB drive, a safe size for SCSI machines. And since my goal at this point is just to get a system, any system, up and running, I just kept the defaults for now.

Installing Mac OS 8.1

Time to install Mac OS 8.1. I plugged in the SCSI2SD and booted the system CD. Then I opened the “Drive Setup” utility to format the new hard drive.

Not supported. 😦

See, on top of using a connection that no one uses anymore, Apple also put in measures to make sure that you only install “Apple-approved” components. In this case, the utility for formatting hard drives has a fixed whitelist of specific brands, models, and versions of hard drives that it can format. So it doesn’t like my fancy new 2GB drive.

There’s a couple ways around this. One is to find a patched version of the program, where enterprising hackers removed the whitelist. I could put that into a floppy image and use the Floppy Emu to load it. Another option is to use a third-party drive utility, again by putting it into a floppy image.

The easiest way however, is to simply lie to the program. 🙂

Despite being a bit complicated to use, the SCSI2SD config does let you configure practically everything SCSI-related, including the vendor and product information reported by each drive. So I just looked up which drives were supported back then, and configured my drive accordingly:

Once I had that set, Drive Setup worked just fine and I was able to initialize my new hard drive. All that was left was to run the Mac OS 8.1 installer, where I gladly accepted the defaults along the way.

First boot and Y2K20

When it rebooted, my first vintage mac in twenty years was finally up and running. It wasn’t the final setup I envisioned for this machine – having multiple versions of the OS on different (virtual) drives, ready to support whatever older mac I want to restore, but it worked. Moreover, so far all of the original hardware seemed to be in working shape. I could read CDs and read and write floppies. If I really needed to, I could even do the tedious work of injecting files into the SD card.

Back in Part III, I mentioned that the first thing when opening the machine up was to replace the PRAM battery. The PRAM battery is responsible for maintaining the clock and some settings, so the first thing I did when the machine booted was to set the clock. Now we run into a funny bit of history – the Y2K bug, or specifically, how it didn’t affect macs. Long story short, many vintage computers saved memory by only saving the last two digits when keeping track of the current year. Their clocks were essentially restricted to dates between 1900 and 1999.

Macs didn’t suffer from Y2K – from the beginning their clocks took dates from 1941 to 2040. But just because the hardware supports 2020, doesn’t mean they didn’t take shortcuts in the software – the control panel for setting the date still takes only two digits, and interprets them as being between 1920 and 2020. So macs have the Y2K20 bug. If you set your clock in 2019, it would have rolled over fine to 2020 and beyond. But there’s no way to manually change the date to 2020 to later.

Thankfully, enterprising hackers come to the rescue once again, with a set of patches for the control panel to let you set the correct date. So after installing that and another reboot, I was able to properly set the clock on this machine, and get on to the very first thing I really wanted to test on an up and running system – networking.

Connecting to the tubes

Even the earliest macs had built-in support for networking, but, as with SCSI, they used protocols and cables that aren’t in use anymore. Thankfully this isn’t one of the earliest machines, and as I mentioned back in Part II, this machine has built-in 10Base-T Ethernet, with the still-standard RJ45 Ethernet jack. It’s literally the slowest possible connection that can still connect directly to a modern Ethernet network without any adapters.

I’d also just spent the weekend running Ethernet cable to my office, for “work” purposes. 🙂

So I grabbed a spare Ethernet cable and plugged the old mac into my switch. A couple clicks through the Mac OS internet settings to enable TCP/IP, and quick double-click on Internet Explorer 3.0.1, and we’re off to the races:

Well, races is a stretch, but success! It’s literally 100x slower than my network can handle, but that’s still 40x faster than an old dial-up modem. A lot of sites won’t work on such an old browser, but I didn’t hook this up to browse the web. Network access means much easier file sharing with my modern computers. Still, I took it for a spin on theoldnet.com, and even filed a bug when the website for the product I work on didn’t load properly.

Well, that’s a lot of progress for one post. Stay tuned for Part VII!

/jon

Want to read from the beginning? Start at Part I.