SE Dual Boot?

[stretch]

I thought I'd pull my SE out of the closet and play. It's a basic SE (not an SE/30) with 4MB of RAM. I replaced one of the 800k floppy drives with a 150MB hard drive years ago and it works well - for what it is.

I decided I'd try to make this machine a dual boot between 6.0.8 and 7.5.3. It'll boot the 800k 6.0.8 install disk 1 and it will also boot a 700MB external SCSI drive with 7.5.5 where the 7.5 installers are located.

Here's what I've done so far. I searched this site and didn't find anything along this line.

I partitioned the 150MB disk into roughly 100MB and 50MB partitions. I've installed 6.0.8 on the first partition and all is well. I installed the same OS on the second partition but the machine refuses to boot on the second partition. As a test, I booted off of the floppy and initialized the first partition leaving the OS installed on the second partition. Now, when I turn it on, I get a flashing happy mac, as if it found a bootable drive, but can't get to it.

I like all my machines to have a dual boot capability. It makes disk maintenance a whole lot easier.

My questions are these. Can a SE actually dual boot from a partitioned hard drive? Is there an additional application that I need to use to make this happen? Has anyone else ever tried it?

 

[Scott Baret]

It is definitely possible to partition drives and dual-boot. It's also possible to do it from an unpartitioned drive if you use the freeware utility System Picker.

Check to make sure your System Folders are blessed on each drive.

 

[zuiko21]

Funny... I've never been able to boot from different partitions with my Quadra 700 -- it always goes to the first partition in the drive, and then the Startup disk control panel shows all the partitions of the drive highlighted! No problem between different drives, though.

On the other hand, System Picker has worked fine for me.

 

[Mk.558]

7.5.5 is noticably slower on my SE/30 than 7.0.1...I would definitely not run anything higher than 7.1 on an SE.

Too slow. Don't forget that 25% of the CPU is spent redrawing the screen.

One other significant change from the Macintosh SE was the use of 64K bytes of separate dual-ported video RAM to control the internal monitor. Since the video RAM was connected directly to the CPU, there was no need for a video buffer in the memory subsystem. This meant that main memory was not burdened with the additional task of controlling video I/O, unlike the Mac SE's memory subsystem. In the original Mac SE design, the CPU had to interleave its memory access (three out of four cycles) with the video circuitry so that the Mac's screen could be drawn. Thus the SE's CPU could only access memory 75 percent of the time. This arrangement degraded system performance. The separate video RAM in the Mac SE/30 allowed the 68030 processor to access memory at each cycle, which resulted in a big win in performance.

Source

 

[stretch]

Funny... I've never been able to boot from different partitions with my Quadra 700 -- it always goes to the first partition in the drive, and then the Startup disk control panel shows all the partitions of the drive highlighted! No problem between different drives, though.

That was the problem I was running into. With 6.0.8 on both partitions, it always booted off of the first partition. I booted off of the floppy and initialized the first partition. At restart, I got a flashing disk, therefore it couldn't see the second partition for whatever reason.

The fix? I started with a 800k floppy drive and a 150MB internal drive. My spare 800k floppy drive turned out to be bad. I added a Super Drive never intending on reading 1.4k disks plus a skinny 40MB hard drive. I booted off each floppy drive for drill and both boot. I initialized both hard drives and installed 6.0.8 on both hard drives. Dual boot works great this way.

Next, I booted from an external 700MB drive and installed 7.5.3/7.5.5 on the 150MB drive. The install took about two hours. Yes, 7.5 is slow on this SE I know, but with 6.0.8 on the 40MB, it is the dual boot that I wanted.

Now, I just need to find a use for this machine. With two internal hard drives, it picked up some weight.