10.2 and FWB SCSI

contoursvt

Registered
Hi everyone,

I have to begin by saying that I'm a PC guy primarily but decided to trade a spare PC (PIII 533) for a G3 400 (B&W). I'm happy with the trade because I have something new to play with.

Anyway here is the question. I want to install OS X 10.2 on this machine which has 384mb RAM, an ATI Rage128, CDROM and Zip (internal). I also have in my hand an older UW SCSI controller for a MAC. Its called a PCI SCSI Jackhammer by FWB I guess. Peeling back the sticker that said Hammer, its a Qlogic 1020A chipset.

Anyone know if an how I can possibly get this SCSI card to boot an 18gig 10,000RPM Seagate UW drive? I want to lose the IDE drive thats in there.

Thanks everyone,
 

contoursvt

Registered
Thanks Cheryl,

I've installed OS 10.2 on a 30gig IDE but pulled the hard drive out in hopes that I can get this 18gig 10,000RPM SCSI drive in there instead. I think there will be no solution due to lack of SCSI support in the operating system.
 

contoursvt

Registered
Actually what I need to do is to drop this MAC :)

Its sad because I actually put this SCSI controller (even though its BIOS is for the MAC) into win2k and it found it and installed it. Granted its not going to be a bootable SCSI card but non the less to control something like an internal SCSI burner or an external tape drive or what ever. Now that is funny! Apple based hardware which works in a PC but not a MAC.

Very sad. The card is now in my AMD XP2100 system with my SCSI CDROM and burner attached to it. Nice to have a dual channel setup.
 

Cheryl

Rosie Moderator
Staff member
Mod
Actually, what Apple is doing is dropping the older connection ports to a faster, easier format. Firewire and USB 2 are faster than SCSI.
Apple was the first to drop the 3.5 floppy. While you may be able to save small documents on those floppies, with today's fat files, using a zip of CD is a better choice. I couldn't use a floppy to save the pictures from my digital camera.
 

btoneill

keeper of the cheese
You really can't compare firewire/USB with SCSI. They are two completely different technologies with completely different uses.

Firewire/USB is a shared highspeed bus designed for connecting devices using the the firewire or USB protocol.Firewire/USB protocol is purely a way to get raw data to and from a device on the bus. Think of firewire/USB as a network for devices on your computer. Firewire/USB doesn't care if the devices is a camera, disk drive, mouse, keyboard, etc, it just sends the raw data to the device.

SCSI is both a shared highspeed bus, and it's standard protocol on the device level. A scsi hd/cdrom/tapedrive/etc doesn't need drivers, as they all use a standard protocol. read/writes/seeks/etc are all done the same way on every scsi hd by the same commands being sent.

A SCSI drive can be on a firewire bus. Any harddrive/cdrom on a firewire bus is going to be either IDE or SCSI, the enclosure of the drive basically converting scsi/ide to work over firewire.

Last, firewire is not faster then scsi, not by a long long way. firewire is 400Mb/sec, SCSI has speeds up to 320MB/sec. The key is, firewire lists speed in bits, SCSI lists speed in bytes. Even standard ultra2 is 40MB/sec, which is 320Mb/sec. So, the high end scsi Ultra320 is 2,560Mb/sec. Thats 6x the speed of firewire.

Brian
 

Cheryl

Rosie Moderator
Staff member
Mod
You gave a good explaination. Thank You. But I have one question. If SCSI hd/cdrom/tapedrive/etc do not need drivers, why are drivers for those items installed? If you have a SCSI scanner you can't run it until you install the driver. The same with a CD drive.
 

btoneill

keeper of the cheese
Originally posted by Cheryl
You gave a good explaination. Thank You. But I have one question. If SCSI hd/cdrom/tapedrive/etc do not need drivers, why are drivers for those items installed? If you have a SCSI scanner you can't run it until you install the driver. The same with a CD drive.
I guess it should have been stated that it's a standard driver for most scsi devices. A scsi hd driver works with any scsi hd, a scsi cd driver works with any scsi cd drive, a scsi tape driver works with any scsi tape drive. They all use the same underlying protocol. This may seem like a big "duh! why wouldn't they use the same driver?", but, it wasn't that long ago different hd vendors had hd's that connected via different protocols, and had their own drivers for their choice of protocols. We had SCSI, IDE, ESDI, st-506, parallel, serial port, you name it.

The same is true of IDE harddrives, and ATAPI cd drives. I can stick any scsi hd on my computer and the computer will see it. (burners are a bit different, as they can add in extra proprietary stuff, but they will still be usable read only). When you connect your "firewire" hd, it's really an IDE or SCSI drive, and the OS's underlying IDE or SCSI driver takes car of I/O. There are some devices like scanners that don't have a scsi standard, they use the scsi bus, but they require drivers just like if it was on firewire/usb. Things like scanners IMHO work much nicer on buses like firewire as it's easy to do hot swapping of devices, it's much harder to add/remove scsci devices on the fly, but scsi has always been more based towads storage then anything else, but man vendors found that the bandwidth of scsi was much faster then anything else at the time for what they needed. Not many things existed to connect a scanner at 10MB/sec 10 years ago.

It wasn't that long ago the IDE cd drives required all sorts of wacky drivers. If you had an IDE cd drive, there wasn't any standard, every vendor had their own proprietary standards, so if your OS didn't have a driver for that cdrom, you were out of luck, then came along ATAPI, which finally made ide cd drives work like scsi. Infact ATAPI cd drives accept alot of the same exact commands that a scsi cd drive takes which was done to make it easier to write drivers for them (i assume, maybe they were just lazy, who knows).

Basically any device on the scsi bus broadcasts what type of device it is, so that the host knows which scsi driver to use for the device.

And if you really want to be confused even further, alot of firewire is based on the SCSI3 specifications with regards to how it talks to disks/cdrom devices :)

Standards are such a great things, there are always so many to choose from :)

Brian
 

Cheryl

Rosie Moderator
Staff member
Mod
Brian,

Another great explaination.

Contoursvt,

Did you give up getting a SCSI controller for your Mac? You could try using a SCSI to USB adaptor.
 

ksv

web developer
Ok, how much are you selling that G3 for? :)
 

Cheryl

Rosie Moderator
Staff member
Mod
Give him time to learn his Mac. He'll soon want to get rid of his PC ;)
 

contoursvt

Registered
Not a chance guys :) I've got the following in my PC and its rock solid and freaking insanely fast and does everything I need.

AMD XP2100 on an Epox board
1024MB DDR Ram
Geforce4 Ti4200 128mb video card
DVD Ram drive (hitachi)
24x Burner (LG)
3com 905C ethernet
Soundblaster Audigy
Adaptec 3960D dual channel U160 controller
Seagate 15K 36LB SCSI drive 18gig (boot drive)
Quantum Atlas 10K III 18gig drive (2nd drive)
Seagate 5400RPM Elite 47gig (3rd drive)..2nd channel
Samsung 900NF 19" monitor

Believe me when I say I'm completely happy but I will be honest and say that I will never drop SCSI for IDE. Not now, not for a long time. When I traded that old PIII for a G3, I had hoped that I would run OSX on a decent 10K SCSI drive which I had. Since I cant, I'm dropping the G3.

Anyone can say what they want about IDE being as fast as SCSI, maybe its true for single tasks but as soon as you start running multiple things then SCSI burries IDE. I've built enough systems for clients to know this. IDE is great but not for a power user who expects to run lots of things at the same time and doesnt want to feel a degredation of system performance. I would have kept the MAC if I didnt have to invest more money into it.

PS. I'm going to sell that G3 for $600 CND which is I think $375 to $400 US I believe. I have a buyer now but if he doesnt follow through, then its going on ebay :)
 
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