• Hello MLAers! We've re-enabled auto-approval for accounts. If you are still waiting on account approval, please check this thread for more information.

System 6 Hard Drive Size?

Tempest

6502
I have two questions:

1. How do you tell how big of a hard drive you have with System 6?

2. What is the maximum size hard drive you can use with System 6?

 
I think get info is in system 6 if not double click on the hard drive icon and the bytes size should be in the top bar of the window.

 
So if I put in a large hard drive (say 80GB) how many 2GB partitions can I make?  Obviously I wouldn't make that many, but I have access to a rather large hard drive and I thought it would be nice to make two or three partitions for all the games I have kicking around.

 
Last edited by a moderator:
HFS Format can access 2TB but the system limits it to 2GB. You can partition such a drive into 2 or 3 2GB partitions but you also need to partition the large unused part and not format it.

In this case is better to go SSD either SD2SCSI or CF2SCSI and use a 8GB card and partition that into 4 - 2GB slices.

The thing is this - you can format bigger partition than 2GB but you will get partition mis-match errors and unable to write files errors. The system just cant access the drive to read/write files to the partition though the partition is there and it can see it and any files you put on it (through another system like OSX).

 
defor posted about this many moons ago.

In the system 6 days, 2GB was the official maximum limit for an HFS volume.

I personally haven't seen or heard about system 6 successfully using a bigger local volume, although system 7.6 and above can easily do so.

If  system 6 will even recognize that the above-2-gig volume is a real volume, there's no real telling what will happen.

The suggestion that it will "work but be erratic" comes from an Apple TIL/KB article about system 7.5.2, which was massively buggy and horrifically crashy, compared even to the "it's just a regular day on a Mac" level of crashiness that you might see using Mac OS 1-9.

What's even worse is that 7.5 was supposed to support up to 4-gig partitions, but 7.5.2 just couldn't do it. At least part of the story is here. I'll have to look around, the wording suggests that 7.5.2 should be fine, but either I'm mis-remembering this article or there's another (even more vaguely worded article) suggesting that there might be problems, Apple doesn't know, but use small volumes just to be sure.

 
I think what he wants to know is the limit for the physical drive to be recognized by the system. That's a good question.

The SCSI of that era should be 24-bit LBA, if I'm not mistaken, so that's a hard limit for 8.4 GB.

If you put a larger drive in, the system will probably physically not recognize it.

 
Last edited by a moderator:
If  system 6 will even recognize that the above-2-gig volume is a real volume, there's no real telling what will happen.

The suggestion that it will "work but be erratic" comes from an Apple TIL/KB article about system 7.5.2, which was massively buggy and horrifically crashy, compared even to the "it's just a regular day on a Mac" level of crashiness that you might see using Mac OS 1-9.
I do know (having done this last year) a partition larger than 2GB System 7 will make the system act funny. Not going through every step, I will summarize the following:

- Using a 8GB CF on PCMCIA adapter, I partitioned it for 4GB partitions then 2.5GB partitions, and then 2GB partitions. It was able to format and give a Disk icon on the larger partitions but it could not could not write a system to it. It gave a "unable to rite file" error. I put the CF onto a OSX machine and put some files on it and it copied fine. Put it back in the 190, the file were there, but could not read them though the file icons were visible. And the amount of free Space was some odd low number on top of everything.

- Using the 2GB partition cleared things up. Files read and wrote, partitions formatted, free space showed up properly. Best of all a system installed and it booted.

- The idea was to format the CF in the PCMCIA and make it usable for a 1400cs with a dead hard drive. Switching Start Up Disk, and the 190 booted off the CF. Putting the CF into the 1400's IDE Port and it booted. No problems since. Later on I repartitioned it for 4GB and OS8.1 and it still works fine. But for System 6 and 7... the max is 2GB. 

I think what he wants to know is the limit for the physical drive to be recognized by the system. That's a good question.

The SCSI of that era should be 24-bit LBA, if I'm not mistaken, so that's a hard limit for 8.4 GB.

If you put a larger drive in, the system will probably physically not recognize it.
That is an interesting question.

Because I stayed within those 2GB/4GB partition boundaries, the largest drives I ever put in a 68K Mac is a 8GB, I would not know how big of a drive can you put in. It's strange because I seen posts of "my hard drive died, can I use a 500GB replacement?" and when they do, the drive is dead to them. In some other cases, like in a smaller drive of 50GB, it works, sometimes.

For me, I figure - how big is the 68K (and later PowerPC) Mac Software Library? A couple of gigs? Of that, how big is my Mac Library? Less than 240MB. So why would anyone need a couple hundred gigs or even a tetrabyte of space for their Old Mac Software Library? Or their Multi-Media Library? 4 - 8 GB, I can see as a reasonable size for an old Mac System. But that is my opinion.

 
Apparently the limit for the OS, before 7.5.3, is 8x2GB volumes on a single drive, so 16 gigs total. Considering the rest would be a waste, I guess that should be considered the ultimate practical upper limit for any System below 7.5.3.

I've never tried anything larger than an 8 GB drive, so I can't say for sure either. Apparently the limit is the size of the LBA per LUN that can be handled by the SCSI driver. Considering System 6 is purely 24-bit, 8 GB per physical drive seems like a reasonable limit. I don't see how the driver could work with more bits than the system allows.

 
Last edited by a moderator:
Where does the concept of a limit on the number of partitions come from? Even at 512x324 you should be able to display a lot more than just eight disk icons on the screen.

Incidentally, I've seen several people use really big (like, 73-gig) SCSI disks on machines that were capable of running system 6. Because SCSI was designed to be generic and not exclusively for storage, it strikes me as odd that there would be LBA issues at all.

Elfen: It's nice if you only have 240 megs of software, but some of us have over a gig just of things Apple released in the systems 7 and 8 era. Hell, most Performa install CDs from the 68k era have well over 400 megs of stuff on them.

Plus, there's issues like difficulty finding small CF/SD cards moving forward that may motivate people to know the real limits so they can get as much out of that storage as possible. If somebody buys an Aztec powermonster CF reader and a 32-gig card, there's no reason to tell them that, for example, system 7.6 needs them to run 2-gig partitions. 7.5.3 and 7.5.5 (you should never run 7.5.2) should run 4-gig partitions as well.

 
Thanks for all the information.   The reason I ask is that I have access to a whole bunch of 40-80 GB SCA SCSI drives (last one on this page  http://www.obsolyte.com/faq/ ) and I thought it would nice to put them in my Mac Classic (and my Amiga 2000 but that's a post for a different forum).  Since the Mac uses 50 pin SCSI I found an adapter ( http://www.ebay.com/itm/201042738862) to make it fit.  I figured I'd just make a few partitions and leave the rest of the drive unused.  It *should* work, but I guess I'll have to see if the system recognizes it or not.

 
Last edited by a moderator:
I predict you will have zero trouble with the size of the drive, like literally millions of people before you.

One thing you may need though is to terminate the highest 8 bytes of the 16-bit SCSI drives when using them on the 8-bit Mac (or indeed Amiga) SCSI chain.  You can buy adapters with the termination resistors already on them, or you can solder them on yourself.  There are threads about doing so around this forum someplace.

 
Doesn't the Mac already provide termination on the internal connector?  I don't recall having to fiddle with that with the drive that is currently in there, or is this different because it's a SCA SCSI drive?  

 
Last edited by a moderator:
Ok, if people can use drives that size, then the limit must either be 137 GB from 28-bit LBA, or 2.2 TB, which is the limit of a 32-bit operating system.

 
Doesn't the Mac already provide termination on the internal connector?  I don't recall having to fiddle with that with the drive that is currently in there, or is this different because it's a SCA SCSI drive?  
No, Macs do not provide internal termination. On certain models like the IIfx, a resistor block is added to the internal jack because it is more prone to signal bounce than on previous models but that's it. Any internal drive in a Mac must be terminated themselves - even if the Mac is terminated. There is a row of pins next to the SCSI Jack on the drive. If those pins are empty, then you need to add the resistors there. If there are resistors there, then it is terminated.

On some newer drives, there is a jumper setting for termination and no need for resistors as they are built into the board.

Elfen: It's nice if you only have 240 megs of software, but some of us have over a gig just of things Apple released in the systems 7 and 8 era. Hell, most Performa install CDs from the 68k era have well over 400 megs of stuff on them.
This is System 6 however. How big is the 68K Software Library under System 6? I remember seeing a CD Pack of Apps and things on 3 CDs by one of the User groups that included a lot of commercial software with it.

But I have to laugh, because this reminds me of a student I once had who had one of the first Pentium 3 systems and 8 500GB Hard Drives to give him a couple tetrabytes with a RAID; the software he amassed on that machine was... wow... He had every software and every version of that software ever made (at the time). I had to ask him, "You got PhotoShop 1.0 to CS2, do you use Photoshop?" He answered, "Nope. I just want it to say I have it." I felt like dropping an ACME Safe on his pointy head in hearing that.

What people have is their business. If they want their old Macs to be useful, there is one way to do that. If they want to have their old Mac as a trophy, well, there is another way to do that. I like my old Macs to be useful because I do use every machine I own.

 
Last edited by a moderator:
Back
Top