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An important message from System 7 Today founder Dan Palka
 
 Topic: HD transplant, would it work? (Page 2 of 2)
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  dpaanlka (Profile)
  1024 MB
 
Posted: Tue Dec 09, 2008 8:27 pm
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Why not just do a clean install on the 2300?
  
  wove (Profile)
  Moderator
 
Posted: Tue Dec 09, 2008 9:08 pm
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LCARS wrote:

Thanks for the information. It hadn't occurred to me that the PowerPC chip would have to emulate the 040. It sounds like I should find another 190.


The Apple systems were all "Fat" containing both 68k code and PPC code. It is not that much different from "Universal" under OS X 10.5.

Resource forks in application/system files contained 68k code as they always had. PPC code was added in the data fork. The Code Fragment Manager handled the loading of PPC code. The reason PPC application need more memory when virtual memory is off is because the Code Fragment Manager maps the PPC fragments into virtual memory and turning virtual memory off means that the fragments must remain loaded.

There were a number of utilities available when 7.5 through 8 were current that stripped Fat Binaries creating only 68k or PPC binaries. With 7.5 smaller hard drives were the norm and there were advantages to slimming down application/system files. As hard drives grew in size it made less and less sense to do that.

Typically an Apple installed OS was Fat. It was the default install although one could choose to have an install specific to 68k machines or PPC machines. The 5300, 190 and 2300 shipped with the same restore/install media. The 5300/190/2300 all used the same enabler, which means the enabler must be either 68k or Fat.

System 7.5.2 is an interesting system in one aspect. It was Apple's intention to ship the 190/5300 with Lithium batteries, but one caught fire and they were recalled before the models shipped. Later Systems specifically blocked lithium batteries on the 5300/190. However there is a chance that System 7.5.2 with an enabler might support the Lithium batteries, providing and opportunity to use a lithium battery from a 3400. That would probably provide some very serious run time especially for the 190.

bill
  
  LCARS (Profile)
  32 MB
 
Posted: Wed Dec 10, 2008 2:09 am
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Thanks for the replies. My 2300 is fine (well, it will be better once I get OS 8 off it). My 190 has files from 6th grade that I want to get off, but its power board and motherboard are toast.

It seems cheaper to find a working 190/5300 or try the drive in the 2300, than to find the replacement parts.

Wove- thank you for the info. Its nice to learn new things about System 7. I'm still learning more about the data fork concept. The stripping utilities sound interesting. My IIci has the original SCSI drive and 7.6.1- I wouldn't mind removing PPC code.
  
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