6500 ROM Secret

[Dennis Nedry]

I always knew the 6500 had a lot in common with the TAM. One day I was ripping ROM images on all my Macs to extract perfect startup sound samples (I have quite a complete collection now). Hidden in the ROM of the 6500 is the TAM startup sound. THAT was cool to find.

Which leads me to wonder if there's a somewhat simple way to ENABLE this sound. I'm not exactly sure how it chooses which sound to play. It could be an identical ROM in both the TAM and 6500 that looks for some indication of what Mac it's in, or the ROM itself may be slightly different for each Mac. I'm not really sure but it would be neat to look into. I wouldn't mind having a 6500 that sounded like a TAM.

Does anyone have a TAM ROM image or an actual TAM that they'd like to make a ROM image from? This way we can compare the 2 images and see what, if anything, is different. A Mac ROM dumper ("GetROM") comes with the Windows version of Basilisk II, which you can get here:

http://gwenole.beauchesne.info/projects/basilisk2/files/BasiliskII-1.0-0.20060501.1.win32.zip

In a second or two after launch, it produces a file named "ROM" in the same directory, and that's it!

 

[Franklinstein]

What do you use to extract the sound file from the ROM?

 

[Quadraman]

I always thought the TAM was based on a Powerbook.

 

[Dennis Nedry]

What do you use to extract the sound file from the ROM?

They're stored as uncompressed, raw samples. So you can import the whole ROM into an audio editor and just look at the waveform until you spot something that looks like samples. Tweaking around with sample rate, 8-bit/16-bit, and stereo/mono will eventually get you the perfect sample. Clipping out the sample is as simple as zooming way in. You will plainly see where other coding ends and the sample begins, etc.

Original Mac, Mac LC, and Mac II style sounds don't have samples that you can easily extract. The Mac LC sounds like it's sampled, and maybe it is, but it would at least require some reverse engineering to get it out.

There are all sorts of other cool little sounds hidden in ROMs that are kind of cool to find. For example, the 6100 and possibly others have a sound effect from Sonic the Hedgehog when you pick up a shield.

I have a pretty good collection of extracted and recorded sounds that far exceeds what's included in MacTracker. It's very interesting to see how low-fi the sounds are. The most popular sound, still used today, is 22.050 kHz!

Here are the ones I've gotten out so far (Recordings are indicated):

http://benboldt.spymac.com/startup.zip

Note that the Mac Plus sounds are pulled from an emulator, so they are possibly very accurate.

 

[Dennis Nedry]

I always thought the TAM was based on a Powerbook.

You're right, some things are based on PowerBooks. Here's a rip from Wikipedia that explains it pretty well:

As noted, the technologies used inside the TAM were not new. The LCD display was out of the current line of PowerBooks. The keyboard and trackpad borrowed from the PowerBook 3400. The TV/FM tuner was an optional extra available to several lines of Macintoshes, including the Power Macintosh 5500 and 6500. The logic board had similarities also to that of the 5500 and 6500 series, though it was in fact a custom board.

 

[techfury90]

What do you use to extract the sound file from the ROM?

They're stored as uncompressed, raw samples. So you can import the whole ROM into an audio editor and just look at the waveform until you spot something that looks like samples.

I've heard that the same thing can be done with the SGI ROMs.

 

[equant]

Dennis,

Nice info about the roms. Out of curiosity, why do you have the Powerbook 165 listed as "Really Wanted" compared to the rest of the PB1XX series?

 

[Dennis Nedry]

I used to have a PowerBook 165 years ago, so I guess it's a personal, nostalgic sort of thing. The "really wanted" status isn't typically based on how much money they're worth on my list. I put that label on any that I think would add the most diversity to the collection, and also some of the more rare models.

The Centris 660AV also is on there for personal nostalgic reasons even though I have 7 6100s which look nearly identical. Specifically I would want the Centris with auto-inject floppy.

 

[Dennis Nedry]

Does anyone have a 20th Anniversary Mac they could make me a ROM image with? I would like to compare the ROM to that of the Power Mac 6500 and see if there is any difference.

If you have one, please download this:

http://gwenole.beauchesne.info/projects/basilisk2/files/BasiliskII-1.0-0.20060501.1.win32.zip

and run the GetROM program on your cool Mac and send me the file named "ROM" that it creates. This will not hurt your computer in any way. It simply makes a copy of the ROM into a file.

 

[z180]

http://kdxvcfa.dyndns.ws:8080/Downloads%201/ROMs/apple%20mac/

They have a lot of older Mac Roms,IIe and LISA too,

but not for the TAM Mac.

 

[applefreak]

Does anyone have a 20th Anniversary Mac they could make me a ROM image with?

get the rom :

rom of 20th anniversary macintosh

"Dennis Nedry" got the file

so he can play around with it ...

file removed of my server

 

[Dennis Nedry]

I FINALLY got a chance to look at this. Interestingly, the Power Macintosh 6500 and the 20th Anniversary Mac have IDENTICAL ROMs. MD5 produces the same checksum for each. The code in the ROM must detect whether it's in a 6500 or a TAM. I ALMOST wonder if it's possible to trick it somehow and have a 6500 play the TAM startup sound.

It seems like because the ROMs are identical the two machines should have the same gestalt ID, so it may be detecting this some other way.

I have a Power Mac 5500 but I have not ripped the ROM and it's stored where I can't get to it right now. But when I get the ROM off of that one, I'll be sure to let you know how that one compares.

I really thought for some reason the ROMs would be just slightly different at least because of the startup sound, so this is kind of interesting.

 

[LCGuy]

Just checked MacTracker, and they have similar, but different Getstalt IDs. The 6500 has a Getstalt ID of 513. The TAM, however, has a Getstalt ID of 512.

 

[Dennis Nedry]

OK, so I'm thinking about where gestalt ID could be coming from. Apparently it's not in the ROM since the ROM is identical yet the IDs are different. The ROM must set the gestalt ID based on what hardware it finds on the logic board. So somewhere outside the ROM, on the logic board, there is an actual electronic difference between the TAM and 6500 logic boards.

I guess I always thought, assumed even, that the gestalt ID was stored directly in ROM, but this proves that it indeed is in RAM at least for this model. This would explain how a utility like Wish I Were could exist; all it has to do is modify this RAM location.

What would be really cool is to be able to run a debugger and step through just until the gestalt ID is set, then modify it to be the TAM gestalt and see what happens if you resume operation. I bet you'd hear the TAM startup sound on a 6500.

 

[Christopher]

file removed of my server

Well thats not very nice. [] ]'>

 

[Mike Richardson]

The ROM is copyrighted and he probably doesn't want to keep it on that server very long.

 

[slomacuser]

I remember that there was a control panel that changed the Quadra's 700 secret startup sound it has built in ROM

 

[Dennis Nedry]

WHAT?! I have GOT TO TRY THIS on my Quadra 700!! I'll look around, but if anyone recalls what this was called, please let me know! This could be very cool.

 

[slomacuser]

Easter Egg ROM soundsFrom: dschaub@csc.uvic.ca (David Schaub)

Quadra From: bylsma@unixg.ubc.ca (Dieder Bylsma)

--------

Many computer systems also have sounds hidden in the ROM. To find them a program called ROMmie is required. The Quadra is PowerMac accelerated. Besides the start-up sounds, which you will find, there may also be other sounds like the ones listed below. The "Whoop there it is digitation" is 16 bit and very cool, but you will need to go to my web page to download it. David Schuab has a huge collection of start-up sounds along with these hidden ROM eggs. If you would like the file send a mesage to dschaub@csc.uvic.ca.

Mac Quadra Squeak - Macintosh LC 520

PowerMac Beep - Power Macintosh 6100/60AV

PowerMac Boing - Power Macintosh 6100/60AV

PowerMac Card Phaser - Power Macintosh Quadra 610 with PPC Card

PowerMac Card "Whoop There It Is" digitization - Quadra 610 with PPC Card

PowerMac PCI Bang - Power Macintosh 9500/120