Booting and gray screen...

[macgeek417]

ahhh... So the 3 meg one is rom, and the two 512k ones are flash?

[macgeek417]

Oh, and the "even" and "odd" parts are the same as the "hi" and "lo" parts I've seen on some other roms??

[Dennis Nedry]

Do you think it would be possible to install the Flash chips back into the PEX, boot into Mac OS 9, and use a software ROM dumper run right on the Mac? I'm not sure exactly how this would work with 2 separate ROMs like this, but it might be a safer approach. It could potentially work. I can de-interleave the dump back into two 512k dumps that you could then burn to new flash chips if this works.

It's also possible that you'll only get the ROM SIMM to dump this way. There's no telling.

[macgeek417]

If someone can get a PM9700 running, it'd be neat to write an emulator for it

[Dennis Nedry]

ahhh... So the 3 meg one is rom, and the two 512k ones are flash?

They're both ROM. The 3MB one is the ROM SIMM, and the 1MB (2*512k) is flash.

Oh, and the "even" and "odd" parts are the same as the "hi" and "lo" parts I've seen on some other roms??

Could be. The Flash ROM is stored in two separate flash chips, and it is easier in some situations to interleave the data between the 2 chips. With this one, 4 bytes come from "lo", then the next 4 are from "hi", next 4 from "lo", etc. Back and forth like that. It's not always 4 though. I have written a small program for this that de-interleaves the two files back together into one big file so I could pull the sound samples earlier in this thread.

If someone can get a PM9700 running, it'd be neat to write an emulator for it

Once we get a proper dump of this ROM, you may be able to use it in SheepShaver. That would technically be an emulation of a 9700.

[macgeek417]

Cool!

And maybe the flash goes toward the front, the end, or somewhere in the middle of the data in the ROM SIMM; Maybe they could be somehow combined into one ROM image so we could actually run it in sheepsaver; I don't think sheepshaver could/would accept 2/3 files as the ROM

[macgeek417]

Oh, and could you email me this program
EDIT: I could PM you my email adress

[Dennis Nedry]

This is also a bad dump. Your data bits seem fine now, but your address bits are screwed up. 1 means working, 0 means "stuck", x means not used:

MSB <---> LSB
xxxx xxxx xxxx 1000 0000 1111 1111 1111

I believe this is the way that the address bits are stuck now (not certain though!):

xxxx xxxx xxxx x010 1000 xxxx xxxx xxxx

Please be very careful; it is possible that your dumper could damage the flash chips if it isn't set up properly. I would recommend researching the pinout of the flash chips and verifying your adapters and dumper configuration.

I have just verified the way that the address bits are stuck. The above info is correct.

[macgeek417]

Couldn't you just combine the two corrupt ROMs to get a complete one?

[Dennis Nedry]

Couldn't you just combine the two corrupt ROMs to get a complete one?

No. We have most of the information but we're still missing some.

[~Coxy]

BOTH STARTUP SOUNDS are in the digibarn flash dump. The normal one and the one nobody has ever heard.

The original flash dump contains YET DIFFERENT startup sounds. The first one is the 6300 sound on the left channel with someone saying "I know that I rescued this company" on the right. The second one is someone saying "Kill me!" I'm working on figuring out exactly how to interleave these files together so I can then figure out exactly the attributes of the audio, after which I can extract some good samples for everyone to hear!

Sounds like a Gil Amalio quote to be, although even Google didn't know.

[jimjamyahauk]

Do you think it would be possible to install the Flash chips back into the PEX, boot into Mac OS 9, and use a software ROM dumper run right on the Mac? I'm not sure exactly how this would work with 2 separate ROMs like this, but it might be a safer approach. It could potentially work. I can de-interleave the dump back into two 512k dumps that you could then burn to new flash chips if this works.

It's also possible that you'll only get the ROM SIMM to dump this way. There's no telling.

The PEX ROM SIMM dump was generated by booting into OS 9 - apologies for not stating this. Only the 3MB is recognised - the 1mb on the flash chips doesn't seem to be counted,

[jimjamyahauk]

This is also a bad dump. Your data bits seem fine now, but your address bits are screwed up. 1 means working, 0 means "stuck", x means not used:

MSB <---> LSB
xxxx xxxx xxxx 1000 0000 1111 1111 1111

I believe this is the way that the address bits are stuck now (not certain though!):

xxxx xxxx xxxx x010 1000 xxxx xxxx xxxx

Please be very careful; it is possible that your dumper could damage the flash chips if it isn't set up properly. I would recommend researching the pinout of the flash chips and verifying your adapters and dumper configuration.

I have just verified the way that the address bits are stuck. The above info is correct.

For reference I'm using this USB-based programmer/dumper: http://www.mcumall.com/comersus/store/c ... oduct=4225 with this PLLC32 adaptor http://www.mcumall.com/comersus/store/c ... oduct=3104.

The second alternate dump I did was using this adaptor: http://www.mcumall.com/comersus/store/c ... oduct=3202 but I'm going to stay away from that as I believe the other adaptor is the correct one to use.

I've only set the software to read the chip, so no accidental erasing will occur - although I take your point about the reader corrupting something. I'm going to re-dump the original flash chips that came with the board to check that the dumper can still produce a correct result. I'll then try again with the Digibarn chips.

Of course, if you've got any tips on further configuring the dumper, or processes of verification it would be much appreciated.

[jimjamyahauk]

What's the differance between the flash chips and the rom simm?

This is a strange Mac. It has one part of the ROM stored in flash chips and a different part of the ROM stored in a ROM SIMM. They aren't redundant; both are apparently necessary to boot the Mac. We're not really sure how they work together but we do know that the startup sounds are stored in flash.

My theory is that the flash chips contain open firmware (OF) and the very low-level code to get the machine to load up OF. This is why the OF version changes when I've put the Digibarn flash chips into the motherboard. As the ROM SIMM is only 3MB I think this doesn't contain any OF.

On NewWorld ROM machines the startup from is only about 1MB in size (such as the B&W G3). Also on NewWorld machines (which load the Mac OS toolbox ROM from file) the Mac OS ROM file is 3MB. On the Beige G3 (oldworld) the ROM SIMM is 4MB.

I suggest to boot into the classic Mac OS on the PEX the following process occurs:

1) OF loads from the flash chips,
2) Boots to the default device of OF APPL,ROM
3) In this case the start memory location of APPL,ROM is within the flash chips.
4) This then plays the second startup sound and then points to a memory location which is the start of the Mac OS toolbox ROM from the SIMM.

In comparison the oldworld boot process is:
1) OF loads from the onboard ROM / ROM SIMM (in Beige G3s)
2) Boots to the default device of OF APPL,ROM, which then loads the Mac OS toolbox ROM (stored on the onboard ROM/ROM SIMM)

The newworld boot process is:
1) OF loads from the flash chips on the motherboard
2) OF locates the Mac OS ROM file on the chosen boot device
3) This is stitched into the OF memory and APPL,ROM is defined in memory as the boot device.
4) Boots to the default device of OF APPL,ROM, which then loads the Mac OS toolbox ROM

Normally a ROM SIMM added into a board would complete disable an existing onboard ROM, but as people have noted they seems to coexist. It's almost a half-way house between the oldworld and newworld ROM architectures.

I found the documents below useful reading in understanding the classic Mac OS boot process. Mac OS X simply uses OF to load BootX and the Kernel, and does not use the Mac OS toolbox ROM at all.

http://developer.apple.com/documentatio ... pgfId=3296
http://support.apple.com/kb/TA29027?viewlocale=en_US

[jimjamyahauk]

A couple of things I'll try tonight are the tips in this forum about seating the device, as one of the problems with the Digibarn chips is getting the Device ID recognised:
http://www.mcumall.com/forum/topic.asp? ... s=am29f040

The forum post also confirms that the PLCC32-DIP32 is the correct adapter to use (http://www.mcumall.com/comersus/store/c ... oduct=3104)

I've checked the the software has the correct device id for the chip, which it does:
http://www.ourchip.com/NZILIAO/chips/me ... 29F040.pdf states that the manufacturer id is 01 and the device id is A4.

The software has this entry for the chip (applies to 29F040 and 29F040B):
Name="AM29F040B",ID="01A4",Class="29F040B",Category="FLASH",MFG="AMD";

[Dennis Nedry]

Your setup is a good one; I don't think you have to worry about damaging the chips.

Interesting that your original flash ROMs dumped properly but not the Digibarn ones.

I would try to reduce the speed of the dumping process if you can. I would think that's the most likely to make it work. RAM/ROM can be very picky about timing.

Next, if that doesn't work, I would dig out a 32-pin DIP socket with long leads, similar to this:



You can see the pinout here of the ROM with and without your PLCC <-> DIP adapter:



Insert your flash ROM into the adapter, and now the pinout of the adapter is the same as the left, DIP pinout in the image above. Insert the adapter (containing the ROM) into the DIP socket (top image), and simply bend DQ3 out of the way, and then DQ4 into its place.

If this works, the dump will still be screwed up, but it should now contain the missing bit, making it possible to mathematically derive a good dump from it, combined with your previous dumps.

There are some other experienced people here that could verify that swapping data bits like this is not a dangerous thing to do if you feel uneasy about it.

[jimjamyahauk]

Right, I think I've got a proper dump this time - selected the slowest speed and it worked fine for the even ROM chip and was a bit more flakey on the odd ROM chip - but eventually got a successful ID check, read and verify.

The latest dump is here: http://www.jkalittle.co.uk/jkalittle.co ... _dump3.zip

The even dump now starts with 0x 4800 0008

James.

[Dennis Nedry]

Right, I think I've got a proper dump this time - selected the slowest speed and it worked fine for the even ROM chip and was a bit more flakey on the odd ROM chip - but eventually got a successful ID check, read and verify.

The latest dump is here: http://www.jkalittle.co.uk/jkalittle.co ... _dump3.zip

The even dump now starts with 0x 4800 0008

James.

Dump 3 was successful!

Original, de-interleaved into one file:
http://www.d.umn.edu/~bold0070/temporar ... ed.bin.zip

Dump 3, de-interleaved into one file:
http://www.d.umn.edu/~bold0070/temporar ... ed.bin.zip

Dump 3 sound 1:
http://www.d.umn.edu/~bold0070/temporary/digibarn1.aif

Dump 3 sound 2 (PEX sound):
http://www.d.umn.edu/~bold0070/temporary/digibarn2.aif

Original sounds (same as before):
http://www.d.umn.edu/~bold0070/temporary/OF_2.0a9.aif


The PEX sound is cut short, but it also has a subtle fade-out at the end which clearly indicates to me that this was on purpose. I believe these dumps are all good now.

[macgeek417]

Cool!

So... Any way to combinr the SIMM dump and the Flash dump so I can run it in sheepshaver?

[Dennis Nedry]

Cool!

So... Any way to combinr the SIMM dump and the Flash dump so I can run it in sheepshaver?

I don't know. Maybe but it's probably not worth the trouble. I don't see how it would work any different than, say, a 9600 ROM. You would probably have to tweak SheepShaver. Notice that SS doesn't have a startup sound when you first launch it. So it isn't probably using the whole ROM anyway.

[macgeek417]

...Or sound emulation hasn't started yet?

[Dennis Nedry]

Duplicating the Flash chips should be easy now, but do you have any plans to duplicate the ROM SIMM?

[jimjamyahauk]

Duplicating the Flash chips should be easy now, but do you have any plans to duplicate the ROM SIMM?

Yes - I bought a tape of 10 same model AMD FLash chips to ue to duplicate the flash dumps on - will be doing this and testing them soon.

I will try to duplicate the rom simm - or design one which has removal flash chips for the rom simm socket.

Somone on the applefritter forums already has pcb layout schematics and pinouts for rom chips that he helped design/manufacture for powersurge/beige g3s and clones.

If you know anyone that knows anyhting about this that would be good to know.

[System7]

The guy saying " I know that I rescued this company" is Gil Amelio. That voice matches up with his in an apple press release.

[jimjamyahauk]

The guy saying " I know that I rescued this company" is Gil Amelio. That voice matches up with his in an apple press release.

Fascinating - my other half doesn't like this startup tone - says it creeps her out!

Do you happen to have a link to an audio press release of Gil Amelio - I've tried Google but to no avail.