EEVblog #414 - Apple Macintosh SE Teardown

[Shred]

My first 'real' job was working for an Apple dealer when these were a current model.

The keyboard (and I think the mouse too) in the teardown is off a later model computer of the Classic / IIsi vintage.  The regular keyboard for the Mac SE was functionally the same but bigger, heavier and chunkier with proper replaceable key switches.

I suspect that the plate stuck to the bottom of the Mac was for mounting the computer on a swing-out monitor arm.  The arms were very popular in the late 80s and used all sorts of weird and wonderful mounting arrangements.  I've also seen large stick on plates, without the four metal 'feet' used as a security device in University computer labs.

I was always nervous about pulling the plug on the logic board on these machines.  The plug is right under the CRT neck board and if it was tight (usually the case), your hand could jerk upwards and hit the neck board.  I've witnessed the destruction of a Mac CRT by that means.  It's always wise to slip the neck board off first and give yourself a couple of extra centimetres.

Apple were notorious for embedding Easter Eggs in their ROMs.  The photos of the developer team in the Mac SE ROMs were a well known one.  There's some discussion on the background to the "Stolen from Apple" easter egg here:
http://folklore.org/StoryView.py?project=Macintosh&story=Stolen_From_Apple.txt

One of my favourite easter eggs was in the later model Mac LC.  If you hit the programmer switch (actually the <Command> + <Power> buttons on the keyboard) at exactly the right time while the Mac was completing its power on self test, the Mac would "crash": it would emit a full volume screech of tyres, followed by a crash sound!

The SE was a fairly reliable / bullet proof machine - a big change from the earlier Plus which had reputation for developing all sorts of power supply and video faults.

[free_electron]

Those West Germany batteries must have been really well built since after nearly 25 years it still holds over 3.8 volts, in both units!

Nope. Has nothing to do with the build , but with the chemistry.
These cells are lithium thionyl chloride cells. The largest manufacturer of these is Tadiran.
Go take a look what those batteries are used for... And you will understand. Also pricewise they are expensive !
They have a D type cell that pacs 19amphour of energy at 3.6 volt ... A normal alkaline d cell scratches 5amphour at 1.5 volt... Get their DD cell and you get 35 amphour....

Now, these cells have limitations. You cannot draw more than a few milliamps out of them. They are made for backup purposes. Or for pulse operation where they charge a fat capacitor over a few minutes and then the system wakes up for a few milliseconds draining the cap and then restarting the cycle. Examples are those wireless electricity meters. They run off a single tadiran cell for 25 years ...

[SeanB]

I have a pair of Crompton Eternacells next to me, only reason they were removed from service is that the internal resistance got so high that they took too long to charge the 1000uF capacitor attached to them after every current draw, so they had a lot of droop. bought years ago and have been driving a chime set.

[jnd]

Those West Germany batteries must have been really well built since after nearly 25 years it still holds over 3.8 volts, in both units!

Nope. Has nothing to do with the build , but with the chemistry.
These cells are lithium thionyl chloride cells. The largest manufacturer of these is Tadiran.
Go take a look what those batteries are used for... And you will understand. Also pricewise they are expensive !
They have a D type cell that pacs 19amphour of energy at 3.6 volt ... A normal alkaline d cell scratches 5amphour at 1.5 volt... Get their DD cell and you get 35 amphour....

Now, these cells have limitations. You cannot draw more than a few milliamps out of them. They are made for backup purposes. Or for pulse operation where they charge a fat capacitor over a few minutes and then the system wakes up for a few milliseconds draining the cap and then restarting the cycle. Examples are those wireless electricity meters. They run off a single tadiran cell for 25 years ...

I know, I have one 19 Ah cell myself but it has lower open circuit voltage even when it's new so not all thionyl chloride cells are the same. I thought they're good for some 10 years, the meter manual says it's designed to last 5 years and I don't think that Varta model was some special longer life type. I guess it's just conservative rating.

For capacity comparison, alkaline seems to be similar, standard AA cell has nearly 3 Ah while the thionyl chloride one has 2,5 Ah in the same size.

[LaurenceW]

How I LOVE the SOUND of that disk drive! Takes me right back. Hardly any need for a disk activity light, back then!

Dave - interested to learn more of whether there are ways to deal with that bromide-yellow stain - is it a question of dropping the case mouldings in a bath of Hydrogen Peroxide for a bit, or what? I have a number of bits of cherished kit that I'd like to have a go at "restoring" in this way.

[oPossum]

Restore yellowed plastic with retr0brite

http://retr0bright.wikispaces.com/

[andersm]

How I LOVE the SOUND of that disk drive! Takes me right back. Hardly any need for a disk activity light, back then!

It's funny how sometimes old floppy disk and hard disk noises are used as ambient sound effects in sci-fi movies and videogames. Nothing implies high-tech than that old 10MB hard disk you had in the 80s.

[Stonent]

How I LOVE the SOUND of that disk drive! Takes me right back. Hardly any need for a disk activity light, back then!

It's funny how sometimes old floppy disk and hard disk noises are used as ambient sound effects in sci-fi movies and videogames. Nothing implies high-tech than that old 10MB hard disk you had in the 80s.

I was just going to mention the drive reminded me of the original Unreal game (and I think maybe Half-Life as well) when you're walking around a computer lab you can hear the old stepper motors.

Most likely the HD is a Seagate drive.  I used to have an SE and was able to connect a 2GB drive to it with no problems.  I think I also managed to get it to use a IBM Ultrastar 10K 36GB Ultra-Wide drive on it if I recall correctly.

[SeanB]

I have a pair of Deathstars that are SCSI, and will fit in there. 1g each, and of course one works and the other does not............ Also a full height Seagate 2G drive. They came out of an old Phillips server.

[mark5009]

Nice teardown, Dave.

I remember, back in the day when I had SE/30s to play with, that those top Torx screws were a real hassle (as Apple intended them to be -- they were so paranoid about people stealing their ROMs).  Sourcing a 10" Torx bit took a while and cost a bit.  I think I might still have that bit somewhere...

  .. mark.

[PaulHigg]

I just bought a Mac SE.  Can anyone tell me how to discharge the power supply so I don't get zapped.  I have electronics experience but I'd like to know the proper way to do this.

Thanks.

Paul

[yvesdm3000]

Nice teardown of this Macintosh SE. I have a lot of very good memories of this machine as I got one (had to share it with my older brother) in the late eighties. I even teared it down back then myself to install the 4mb ram and harddrive upgrade.

From the looks of it, the disk-drive is the same one as we had, and the brand is "Miniscribe". We replaced it with a 40mb (whoohoo) "Conner" drive which was an order of magnitude more silent than that incredibly noisy Miniscribe.

The keyboard is more recent, more of a Mac-LC type. The original has also ribbons, bigger (but the same amount of keys) and heavier. The mouse matches.

Too bad there is no use at all for vintage PC's, not unlike cars where it would be very neat to drive one from those dates, and be equally functional for todays use (except for the fuel consumtion...)

Thanks for this video, I enjoyed it !

-Yves

[Chris_PL]

I just bought a Mac SE.  Can anyone tell me how to discharge the power supply so I don't get zapped.  I have electronics experience but I'd like to know the proper way to do this.

I usually do it via shorting the suspicious caps through 10R/5W resistor wound on a screwdriver.

Have no idea if this is a proper way, but it works for me. It's much much better than a sudden spark shower while refreshing solder joints etc. and shorting the cap through the tip of an iron 

[wesphillips]

I know that this is a bit late, but if you check the video at 30:03, on the sim city splash screen, you will see that the software is registered to the "Sociology Dept UOW".  I am assuming that the UOW means University of Wollongong.

Also, I in the staff directory, try typing a single character, for example "S", or "R"(these are very common characters in names(), and pressing the "Search" button. I believe that it is the button in the upper right corner that shows a man walking towards the right.