Tidbits: Sad Mac – Memory “Issues” in the Classic

Last night, my mood was soured when the Classic started having issues.

Yesterday I spent my day installing Aldus FreeHand and PageMaker 4.0 on the Classic to play with. I intend to publish a short series of posts demonstrating software on both the Classic and SE.

I spent part of yesterday installing Aldus FreeHand and PageMaker 4.0 on the Classic.

While booting the Classic, I had to change the FloppyEmu from the HD-20 emulation to floppy emulation mode. This involves doing a hard reboot of the machine. After changing the emulation mode, shutting the machine down, and waiting about twenty seconds, I flipped the switch to turn the machine back on.

This time, there was no chime. Instead of a grey screen followed with a “Happy Mac”, I was greeted with the infamous Sad Mac. Oh no.

Unlike the Happy Mac – which means the computer is running properly (or, in the PC world, “passing the POST or Power On Self-Test”) – the Sad Mac means there is an issue with the machine. Typically, the Sad Mac means there is a memory or other hardware problem that prevents the machine from booting properly. (Again, think of it like a computer failing the POST.)

However, after another hard reboot, the machine continued to boot normally.

After completing the installation of FreeHand and PageMaker, I shut the machine down.

Later last night, I decided to fire the Classic back up to play a game. This time, the Sad Mac wasn’t going away.

The infamous Sad Mac error ruined my day.

After many tries and even pressing the reset and interrupt switches, the Classic was not going to move past the Sad Mac screen. Now it’s time to panic.

A look at this handy guide for decoding the Sad Mac error code revealed it was likely a memory error. (Specifically, “the RAM External addressing test failed.) Others on the 68kMLA forums and a Facebook group came up with the same result using the same guide.

Since the Classic has 1 MB soldered to the logic board, that was my largest concern. My Classic has 2 MB of memory installed, with the other 1 MB soldered to the memory expansion daughter card that plugs into the logic board. (I don’t have any SIMMs installed.) If a memory chip on the expansion card failed, I could simply leave the card out and still use the Classic with 1 MB until I got the card repaired. However, if a chip on the logic board failed, I would be out of luck.

Fast forward to tonight, when I finally get a chance to do some testing.

After removing the memory expansion card, the computer fired right up. Chime, Happy Mac, “Welcome to Macintosh”, and proceeded to boot into System 6.0.7 as usual. So the logic board’s memory is good.

To rule out a loose connection or something else, I plugged back in the memory expansion card – this time making sure it was a snug connection. Flipped the switch, and… “bong!” The machine booted just fine again, this time with the memory expansion card back in.

The memory expansion card must have been loose, causing these issues.

Hopefully this is the end of my issues with the Classic. It sure gave me quite the scare and had me anxious all day.

A good lesson can be learned from this: sometimes seemingly complex and worrisome hardware issues can turn out to be something really simple and easy to fix, like a loose connection.