PowerBook 550c Again

I said a few days ago that I might have an update to my PowerBook 550c story. The one I originally picked up has a PowerPC upgrade card. Well, I just acquired another PowerBook 550c. This one has the original 68040 CPU card! It actually works out very nicely. The second PowerBook 550c has the original Japanese keyboard which is a little difficult to work with for me. The first PowerBook 550c has a regular US keyboard. Between the two, I will have a number of parts to work with. I am looking forward to the second one arriving so I can get started with my OpenBSD/mac68k installation.

68EC040, 68LC040, and 68040 Differences

If you have been looking around for 68040-based computers, you may have noticed that there are three different types of 68040 processors. I have long known about the 68LC040 and 68040 versions but the 68EC040 was a new one I had never heard of. The 68LC040 processor has a memory management unit (MMU) but no floating point unit (FPU). The full 68040, the most desirable, has both an MMU and FPU. The 68EC040 which I had never heard of contains neither an MMU or FPU. Macintosh computers have never contained a 68EC040 CPU while both the 68LC040 and full 68040 CPUs have been used.

This might clear up some confusion that some may have regarding these different CPUs. If the purpose of using a 68040-based system is to run NetBSD/mac68k or OpenBSD/mac68k, you really need the full 68040 CPU. There is a NetBSD/mac68k softfloat build available at this ftp site. However, some 68LC040 CPUs have a hardware bug that does not allow floating point emulation to work at all. These CPUs must be replaced in order to function correctly with any NetBSD/mac68k softfloat build. You can read about the details of the hardware bug at this site. Unfortunately, there is no softfloat build available for OpenBSD/mac68k. It is very unlikely that there will be one any time soon.

Information on the Motorola 68040 CPU is available from Wikipedia. You can also look up the 68000, 68020, and 68030 processors. All four of these processors powered 68k Macintosh computers. The final development of the 68k line was the 68060 processor. This final processor of the line was never used in any Macintosh computers. By that time, Apple had moved on to the PowerPC line.

PowerBook 550c

I finally acquired a Macintosh PowerBook 550c. This machine was the fastest 68k PowerBook ever made. It featured a full 68040 33 MHz CPU. This was also the only 68k PowerBook to have an FPU built-in. Without the FPU (like the 520 and 540 series), it is harder to run NetBSD/mac68k and impossible to run OpenBSD/mac68k.

There is one problem with the PowerBook 550c that I acquired which makes it impossible to run either NetBSD or OpenBSD. It has been upgraded with a 100 MHz PowerPC 603e upgrade card. Unfortunately, the original owner could not locate the 68040 CPU card. Now, I am looking for an original 68040 CPU card. That is the hard part. I found a 68LC040 CPU card from a 520 or 540 series PowerBook but that does not help much.

I may have some positive news soon. I will post an update over the weekend.

Introduction

It is about time that I started to post notes on what I am working on in the BSD world. This mostly revolves around OpenBSD but also includes FreeBSD and NetBSD from time to time.