kalleboo's retro tech blog

PowerBook 540c

Buying it & First Boot

Another Yahoo! Auctions find. I was looking out for a 68K color PowerBook with video out. My choices were between the 540c and the 190. Due to the display plague affecting most of the 90's PowerBooks sold on Y!A, I had my eye on a good 190 with a bad display and a dead 5300 with a good display with a plan to combine the parts into something working, but then this one came up. The only problem it had was a missing display hinge plate, which seems to be a weak point on these machines.

Booting it up for the first time, it came right up, and had 7.5.5-J installed on it. All the apps had been deleted, but the system folder had traces of MIDI software.

Initial setup: Using Target Disk Mode, a SCSI CD-ROM and Built-in Ethernet

The first thing I did was connect the machine over SCSI target disk mode to my PowerBook G3 and image the harddisk it came with, in case there were any gems in there that turned out to be important later.

The next step was booting off an external SCSI CD-ROM drive with a System 7.5 CD-ROM, wiping the drive (takes 20 minutes for HD SC Setup to re-format a 500 MB drive!) and doing a clean install of 7.5.

One nice feature of the 540c is built-in Ethernet. SCSI target disk mode is handy when you need it, but since SCSI isn't hot-swap, continually rebooting devices to copy files is a PITA. So the first thing I did after the clean install was done was set up EtherTalk so I could copy files straight over the LAN. The built-in Ethernet on the 540c seems to max out at about 1.5 Mbit (using AppleShare, downloading a file in Netscape is even slower).

It was really nice having an Ethernet LAN of 3 major generations of PowerBooks right next to each other! My G4 Quicksilver also joined in on the fun over WiFi from my office


Once I had confirmed the machine was working well, I started ordering some other parts...

Upgrading: SD PowerMonster SCSI2SD

The first was replacing the built-in SCSI HDD with a SCSI2SD. The built-in drive was working, but whining pretty loudly, and it may be my imagination it the whine seemed to get louder the longer I used it. In addition, having more storage space than 500 MB available is always nice!

The SCSI2SD I got was a domestically-produced one called the SD PowerMonster by Stratos Technology. They're no longer available from the original producer's online store, but they still sell them at the original price on Yahoo Auctions.

I configured the drive to appear as a Seagate drive that's natively supported by an unpatched version of Apple's HD SC Setup to keep setup simple. Then I opened up the machine and installed it, and rebooted off the external 7.5 installer CD-ROM. The machine came right up, and HD SC Setup happily formatted it. HD SC Setup took 40 minutes to format the 2 GB drive! I was worried it was hung, but the cursor was still spinning. Since the Seagate drive I was masquerading as was a 20 MB device, the default partition size was 20 MB, and I had to use the partition tool to remove that partition and create a new, 2 GB one. I then had to reformat that partition again in the Finder (took seconds) otherwise it the installer would error out.

One thing I learned was that the SCSI2SD does not work with SCSI Target disk mode. The PowerBook screensaver goes on showing SCSI ID 2, but the Mac it's connected to shows a SCSI device on ID 0, and refuses to mount it (the Mac I connected to was an IDE Mac so there was no ID conflict). Not really surprising, but worth noting anyway.

I ran a quick benchmark on the original HDD before removing it and compared to the SCSI2SD. The SCSI2SD was actually slower! Could it be the SD card? I just used a spare one I had laying around (Toshiba SD-L032G4 class 4). This SCSI2SD is also based on a pre-v6 version (going by the firmware), and supposedly there was a big performance boost in v6.

IBM DHAS-2540 S640 HDD Benchmark (B's Bench)

SD PowerMonster SCSI2SD Benchmark (B's Bench)

New PRAM/Backup battery

The PowerBook was also not keeping time when it was unplugged, which pointed to a dead PRAM battery. The PowerBooks have a rechargeable backup battery which also keeps the RAM alive when you swap batteries. There's a guy on Yahoo! Auctions who builds new PowerBook batteries of any generation on demand, and while I could do it myself like I did for the G3, this time I was lazy and just ordered one.

To install the backup battery you need to bascially take the whole machine apart, so I did it at the same time as I installed the SCSI2SD

Display issue & repair

On the second day of using the machine, my heart sunk as intereference patterns, jitter and noise appeared on the display. The severity came and went, but it remained.

Reading an unrelated thread on the 68kmla forum, there was a throwaway comment about someone squeezing the bottom left corner of their display stopping the issue, and sure enough, it worked for me too!

I then took the display apart and reseated the connector in that spot.

Work yet to be done

Last updated: 2019-06-25
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