Powerbook 520c

Version Française		 WikipédiA

I had it in 2010
Here the start screen of MAC OS System 7.5.5

What's in the box CPU and RAM upgrade System installation Software ATARI/PC Emulation ZIP et CD Rom External Monitor and Keyboard Renewing the battery

I wanted this machine to make Atari emulation on a 68040. I'm a bit disapointed by the performances that I expected better. But I have some ideas to speed this a little.



What's in the box

  • CPU 68LC040, 25 or 33MHz no FPU
  • 8MB Ram (up to 36MB)
  • 640x480 with 256 colors
  • SCSI, Ethernet, ADB, LAN, Monitor ports
  • Sound Input and Output
  • SCSI Hard Drive 240 MB

One will notice that connectors have a particular format, so adapters will be requiered to use Ethernet, SCSI, external monitor, etc... That's Apple...

25 or 33MHz?

Here is the daughter board with the processor... SURPRISE! It's a 33MHz one... But clocked at 25MHz, certainly to maintain the interest of the Powerbook 540. Apple's marketting.
  1. Processor 68LC040 33MHz
  2. 2x256k static RAM, a second level cache?
  3. a beautiful label 25MHz to distinguish this one from the real 33MHz
  4. The oscillator at 12,5MHz (SG-615p)
  5. frequency/x2/x4 (343S1108), so the processor gets its 50/25MHz.
  6. additional RAM connector, for now, I have 4MB additional RAM and I'm waiting for a 32MB board.


Note: on the back side, 4MB of base RAM.


CPU and RAM upgrade

Clic here to learn how to change:
  • the CPU card to speed it up to 33MHz
  • the RAM card to get more space (from 8 to 20MB in this example)
  • and see the benchmarks before/after acceleration under MacOS and under Atari/PC emulation.


System Installation


Problems ans solutions

If you get a computer with an uncomplete system, or not up to date, you'll want to install Mac OS 7.5.5 on it. It's the most recent system freely available on the Apple site.

But, I couldn't get to: I came to use the last and original solution of the "SCSI DOCK" that turns your Powerbook into an external hard disk... if you have a SCSI card on your PC! What I needed:

The SCSI DOCK adapter with a standard DB25 connector.
Don't forget to switch it ON!

Once on, the MAC displays it's own SCSI ID: here, number 2. Then it waits for a master unit to take control of it.
Be sure to switch ON and plug the MAC before you turn your PC on.
On the PC side, TRANSMAC software gives acces to MAC partitions:
  • floppy disks, MAC formatted
  • CD Roms
  • Hard disks, that's the option I need!
On the Apple WEB site, you'll find the 19 disks images requiered for the installation of System 7.5.3. Download them!
Then, download the 7.5.5 update disks. I only used the NetInstall file that comprises the 3 other disks.

Using TRANSMAC, copy everything to your Powerbook in the same folder.
Finaly, turn everything OFF (Esc key on the MAC, and unplug the SCSI Dock) and reboot your Powerbook.

At last, you'll get the pleasure to use a brand new desktop!

You can see thesystem memory usage, I tried to lower it removing the useless extensions (the ones concerning the PowerPC, Ethernet, Printing, things I won't be using). Here is what I get after some cleaning:


You can see the little tool CAPTURE that allowed me to take the snap shots of the screen for this page, even during games!

Finally, note the accessory to set the number of colors from monochrom to 256 colors. Very useful for old software.


Software


Useful...

The Think Pascal 4.5, after some testing, appears as a complete anf powerful develoment system.. I easely found a second hand documentation (in french, from Micro Applications) and the number of functions is impressive! I think that you can use it both for fast programs using the TEXT mode and for professional ones with menu bars, dialogs and graphics.
The ChipMunk Basic appears to be a cool piece of programming software. Free, you can find it for download.

Here one Basic program you'll find included with graphics ans sprites demo.
The Symantec Great Works 2.0 is a complete office package with colors. As good as ClarisWorks but free and available for download.

Here an example with multicolumns, bitmaps integration and a table.
To test the performances, use SpeedoMeter 4.02 that includes a complete set of tests.
Results are compared to a Quadra 605 that uses the same processor 68LC040 at 25MHz.

This Powerbook is a slower than the Quadra, particularly concerning graphics.

..and fun!

Lots of games are available for MAC, that was a surprise! I had another image of the MAC world.

Here DOOM 1, you'll have to reduce the window to get a smooth display. Then it's a really good adaptation with sounds and music!
The same with Wolfenstein 3D, the window must be reduced to play in good conditions.
Here a good LodeRunner with a special 2 players game!
Cards games with a lot of options.

Here Burning Monkey where the crowd under your cards criticize the action.
More card games, for those who got plenty of spare time...

Here Solitaire Mania.
The classic TETRIS in a version I found simple and pleasant.


Emulation


An ATARI with MagicMAC 6

This software can still be found as an demo version, one of the limits is that you can't use it more than 15 minutes. Then you must restart it.
MagicMAC is not a full emulator as programs are run in native mode on the 68040. The environment is adapted to the Atari using the MMU and redirecting Atari calls for keyboard, mouse, screen...

Easy to install Atari software as you just have to declare a MAC folder as the "C:" unit for TOS.

This system offers the environment ofMagiC 6, that's to say a multitasking system for TOS/GEM software.

Here the desktop with three of my programs.
To test performances, I use Olivier Landemarre's KRONOS.

Results are not so bad for Video/RAM and VDI.

But the lack of FPU unit lowers down the OpenGL performance!
The 68LC040 clocked at 25MHz is seen as a 19,3MHz one.

The mothercard perf is 24, compare this to the 49 I get with a 48MHz TT+Nova. Sure, on the TT, the MC68882 helps a lot!

Some ideas to speed things up:
  • Dig a 33MHz daughter board (the one from a Powerbook 540)
  • Replace the 68LC040 with a full 68040 to get the FPU instructions.

A PC with Soft PC 3.1



ZIP and CD Rom

I wanted to connect a ZIP drive and a CD Rom to the Powerbook.
Here is the complete setup. Cable size isn't a problem as the MAC/ZIP one is 50cm long and the ZIP/CD more than 1m long.

First, install the drivers!
The ZIP driver should be copied to the EXTENSIONS folder fo the SYSTEM folder.
The generic CD driver "CD Sunrise" has its place into the SYSTEM folder.


Then make the connections as shown below:

First, switch OFF the SCSI DOCK.
Then switch OFF the ZIP Terminator as the chain is not finished.
Finaly, switch ON the CD terminator and select SCSI ID = 3 (tradition?)


Go on by turning on the peripherials first and the Powerbook last.
If both drives are correctly initialized, then you should see these icons on startup.
If something went wrong, then a red cross covers the icons.
When everything works, inserting a ZIP or a CD Rom makes its icon appear on the desk. Then, use it as a normal drive.
Note: drag the icon to the trash to eject the disk!


External monitor and keyboard

The Powerbook can work closed!

In this case, the video is routed on the external port and the keyb/mouse input from the ADB port. Here is the complete setting of the Powerbook (you can see it on the tablet over the monitor).

With this configuration, you can benefit from a better display because eyes get tired with a little LCD monitor, even on a Mac.

Here a picture of the connectors in use:



Renewing the battery

My battery was not detected! I had to use the Powerbook with the external power supply and, worse, as the backup battery is dead, all settings were lost when shutting down the computer. This disturbs a lot the Mac to boot with an invalid PRAM.

Here are listed the different possible states of the battery:
  • Black logo: full charge!
  • Logo with a flash: battery must be charged.
  • Logo with a cross: no or defective battery.
At first, I had the logo with the cross even when inserting the battery! So I cleaned the four golden contacts to remove the corrosion that appeared. Then I used the following software:
Intelligent Battery Recondition:

It comes in two parts: the fist to be copied into the EXTENSIONS folder and the second, the program itself, that allows you to reinit your battery.
At the end of every test, I always get this message:

Despite this, the battery has been correctly reset and the charge could be fulfilled.