Hibernate/Suspend to Disk for 68k?

[onlyonemac]

Hi!

We all know that our old Macs start up pretty quick, but still, I'm curious...

Wouldn't it just need to write the contents of memory to disk, and then, at a later time, read it from disk and write it back into memory? Or would the system crash during the re-write process?

Has anyone done this?

Thanks,

onlyonemac

 

[NJRoadfan]

You need ROM level support on a Mac. The stock ROM does one thing, boots the System Software. It would have to accommodate the fact that there may be a hibernation system image on the drive and load it if its available. Before Windows 2000 and ME added native Suspend-To-Disk support to the OS (in conjunction with ACPI), some systems supported it by adding it to the BIOS and hooking the APM suspend function. These functions tended to be limited by only supporting FAT16 HDs, and required an EXE run at boot to load a driver or set aside the hibernation file.

 

[olePigeon]

The Outbound laptop Mac clone could boot/resume from memory. That tripped me out because when I was troubleshooting it, I had removed the HDD and it still booted. :O

Very cool feature.

 

[NJRoadfan]

Was it via a RAM Disk? My Apple IIgs was capable of doing that with the Applied Engineering RAMKeeper. It gave the machine a battery backed RAM disk. In theory the Mac Portable could do it, but I think it clears the RAM Disk on shutdown. Its easier to just put it to sleep since it consumes the same amount of battery power in sleep mode or shut down.

 

[uniserver]

maybe you can find your self a nice Mac Portable.

Here is one:

http://www.ebay.com/itm/Professionally-Recapped-Apple-Macintosh-Portable-M5120-Mac-w-Rebuilt-Battery-/151068091577?pt=US_Vintage_Computers_Mainframes&hash=item232c5c24b9

 

[onlyonemac]

You need ROM level support on a Mac. The stock ROM does one thing, boots the System Software. It would have to accommodate the fact that there may be a hibernation system image on the drive and load it if its available.

But surely we could just run a standard application to dump the RAM contents to a file on the hard disk, and then another application which can be run after bootup (or an extension which does the same thing during bootup) to restore the RAM contents and automagically make the former state appear.
My only concern is that it might crash the system should a VBL interrurpt or a pesky PDS card stick its foot in the middle of the memory re-writing process...

 

[uniserver]