SCSI-IDE bridges

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doug-doug the mighty's picture
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In doing research for my Q950 upgrade and hacks, I came across an animal called a SCSI-IDE bridge (please note that this Q950 is my first REAL dealing with SCSI and/or NuBus macs on such a technical level).

There is a nice selection of these devices at www.micolandusa.com and allmost all of the are Acard products. I have been looking at these and think I know what I need, but wanted to poll the group and see if anyone has ever used/played around with these.

The theoretical limit for devices on the Q950 is 20 (with #7 being the CPU), but the stock OS (7.1) only supports 7 devices. I believe the machine is running 8.1 (I can't remember and it is not with me at the moment), but I will up the OS and CPU as far as I can.

My thinking with this bridge is that I can handle significanlty larger dirves. I was thinking of dropping a couple of 200GB hard drives in if this works okay. From what I read, I would not need anything special on the OS to access the full drives - breaking the 7 device limit will be a different thread later on, but if anyone has any insight on that, post away!

--DDTM

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doug-doug the mighty's picture
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the models I was looking at...

...are AEC7720UM and AEC7720UWM

--DDTM

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Re: SCSI-IDE bridges

doug-doug the mighty wrote:

My thinking with this bridge is that I can handle significanlty larger dirves. I was thinking of dropping a couple of 200GB hard drives in if this works okay.

(That link shoud read http://www.microlandusa.com)

Don't assume that those bridges can handle 200GB drives. They probably don't do LBA (48-bit addressing) or ATA-6 (which is required for drives larger than 138GB or so). In that case, you are certainly limited to "smaller" disks (and not the massive 200+GB available today).

Dan K also notes some issues with drives larger than 8GB in PowerBooks of roughly the same vintage. See his page here: http://mywebpages.comcast.net/macdan/pb_scsi_ata.html.

Given those problems, you may just want to invest in some older 40GB+ SCSI hard drives that can be found on the cheap these days.

Of course, if they don't have those limitations, then GO FOR IT! A Quadra with over 100GB of storage would be EXTREMELY impressive!

Peace,
Drew

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7.1 and hard drives

7.1 and all Mac OS versions prior to 7.5.x (not sure where the change falls exactly but probably 3 or 5) will not see more than 2 gigs of a hard drive. I have an SE/30 running 7.0 and thought about putting a 4 gigger in it when I remembered. While I salute the ambition of what you want to do with the 950, what on earth would you need that much space for? Most of apps that will run on it are less than 1MB in size and the monster apps go to 3 MB. Filling 2 gigs on system 7.x is difficult even with quark or early versions of Photoshop and Illustrator.

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ooops

I'll pay attention next time, I swear. 8.1 not 7.1, right pew, wrong thread.

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large drives supported

I think most (all?) of Acard's current lineup supports large drives. I don't see those bridges you mention on Acard's site, however look at this:
http://www.acard.com/eng/product/scside/aec-7720uw.html

grab the list of supported drives at the bottom, which shows several 250GB drives as supported.

dan k

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doug-doug the mighty's picture
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That is the one...

I also found a link at http://www.xlr8yourmac.com/tips/ramdiskspeed.html that descirbed how using these adapters could enable fast enough read/write to support using the machine as an audio file server in certain applications. Expense aside, I wanted to have a massive repository for holding audio files and other large data projects (mostly archival type stuff and test based document of considerable size).

Yeah, yeah, and because it would be cool to do!

Given the support by the device for large drives, it appears to be a question of the OS supporting large drives. Couldn't I take a 200G and partion it to 2 100G volumes?

--DDTM

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--DDTM ('Fritter Critter' since Apr 26 2004 - 18:16)

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ick

The only SCSI-IDE brides I've ever used were DOG SLOW, and only supported disks up to 4GB.

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re: ick

Ah drbob, must have been awhile since you've played with the things, modern bridges are scaldingly fast. Certainly more than fast enough to saturate any nubus-based Mac's buses.

dan k

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Yes, but...

Dan's right about the performance. Now the only problem is price - they start at $70, which is a bit rich for my blood (and many others' I'm guessing).

I would think they'd start to get relatively economical -- i.e. worth the $$$ for hacking -- at around $40. What do others think?

Matt

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dual ATA drives per adapter . . .

reduces cost to the $35/drive range. Does that make the adapters seem a bit better value?

dan k

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doug-doug the mighty's picture
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say what?

where have you seen these?!?

if that is not speculation, please post the link, cuz I wanna know more...

--DDTM

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--DDTM ('Fritter Critter' since Apr 26 2004 - 18:16)

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re: Say what?

http://www.acard.com/eng/product/scside/ars-2120.html

I confess I don't know the selling price of this item.

Their other bridges may also support 2 drives but their web pages don't mention it. Poke around Acard's site, maybe some other tech docs may help. Also ask about 'em in some of the appropriate usenet groups, there's lots of ATA-SCSI bridge users out there.

dan k

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I have a scsi-ide bridge from

I have a scsi-ide bridge from a cd writer, you can have it for the p+p (i am in England)
Chris Edwards

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tell me more...

is the device a 50 pin IDC connector on the SCSI side?

What is the make and model - I want to get specs on the dimensions as I have a space concern even though it will be going in a Quadra.

--DDTM

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--DDTM ('Fritter Critter' since Apr 26 2004 - 18:16)

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DDTM looks gift horse in mouth?!?!?

Huh?!?!?!?!?

Hey knucklehead!! Just say yes! Laughing out loud

LOL, if you don't ASAP I'll beg for it ASAP!

dan k

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I am not sure of its name but

I am not sure of its name but it is newer than the scusi connectors I am used to, it uses edge connectors not pins, I will look for maker and name tomorrow (it is at work)
Chris
Just checked on a website, I think it is a hd 50 or 68, will doubte check tomorrow
Chris
Looked today the connector is a DB50, three rows of pins, or sockets.
Chris

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appreciated, but...

if it is an edge connector, I doubt I will be able to use it, hence it will go in my garage pile of parts and maybe never see the light of day again. Shipping to and from UK is not the cheapest. I appreciate the offer made, but don't want to waste.

--DDTM

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re: appreciated, but...

"edge connector"? WT . . . err, heck are you talking about? :?

anything resembling what he's got will have a 40 pin connector on one side and a scsi connector on the other.

Still, as you say there's no point paying for its passage and then never using it.

dan k

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Old Powerbook SCSI-IDE

I've got one of the Apple 1.1 GB Powerbook drives which consists of a 2.5" ATA drive sitting atop a SCSI-IDE converter board. Does anyone know if the 4GB size limit applies to them?

Also I'm looking at using it in a desktop, so could I make up a 3.5"->2.5" SCSI converter cable if I get hold of the right connectors, or buy one? edit Anyone have the pinouts for 2.5" SCSI? - Amazing what a little Googling will find http://www.applefritter.com/node/view/4440

I'd rather make one up than buy one, I'm stubborn like that.

Hey if not I could squeeze it into my 2300 somewhere for dual drive fun Smile

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Wrong SCSI

That's the wrong kind of SCSI connector for your Quadra, it's LVD - different size, shape and protocol.

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LVD backwards compatible

as are most SCSI flavors, so most any scsi device can be used on most any scsi chain. Of course, it might take a few adapters to get it all working together

dan k

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Er, which PBs did those come

Er, which PBs did those come in? I've got a 280c w/ a cracked screen and a 1.1ish GB drive. I've also got a 6GB Toshiba 2.5" IDE drive. It would be pretty darn cool to have 6GB in a SCSI PB... Cool Mac

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you might be in luck

I'm pretty sure they came in the later Duos, so open her up and have a look. If the drive is mounted on a big ole circuit board with a tiny drive connector jumpering it to the drive at one end, and a 2.5 SCSI at the other end, that's the beast itself.

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re: Er, which PBs did those come

any 1 GB or larger HD in a SCSI PB is almost certainly an adapted ATA drive. Native 1GB HDs are very scarce, and the adapted drives are very common. The largest common PB SCSI drives were the~500 meggers, IBM or Quantum IIRC. Toshiba made an 800 megger, not as common as the 500s, but not rare.

In all cases, those native SCSI drives are dogs, a modern ATA drive on a modern adapter whips their mangy butts. Tongue

IIRC, Apple shipped some PowerBooks 540C with the 1GB drive, and perhaps a few 280C Duos as well. Most of these drives however were probably sold as upgrades. Apple had a pretty active program selling these 1 giggers to upgraders with the bit of large needed to afford one.

dan k

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SCSI to IDE adapters are great!

Most of the comments appear to be speculation or opinion; let me share some real world experience.

I've had an Amiga 4000 with a CyberStorm Mk III for years. It was colocated as a server running NetBSD for a long time. For a while, I had an 18 gig and a 36 gig on the UW-SCSI interface, and a 75 gig IDE on the motherboard IDE interface. But the IDE was REALLY slow and caused a lot of system overhead when using it.

So I bought one of the Acard SCSI-IDE adapters (the AEC-7720UW) and moved the IDE drive to the SCSI bus. It was MUCH faster (due to the UW-SCSI being capable of doing real DMA), and so I used it as my users' homes for a while.

After months of using it, I figured it was pretty stable and problem free, so I set up a 160 gig drive on it as the system drive. Since it has /var and swap on it, it gets much heavier use than users' homes do, so that was a good test.

Now I have two colocated PowerPCs, one with four 250 gig drives on an Ultra-160 bus with AEC-7726Qs, the other with three AEC-7726Qs on an 80 MB/sec bus.

So not only are they stable, and not only do they support drives greater than 128 gigs, but they're fast as hell, too.

If you run MacOS 8.1, you can have partitions of up to 2 TB, I believe. The only limitation is that if you want to boot off of a large drive, the first partition has to be HFS (not extended), and can't be too large (forget what the limit is).

So there you have it.

John Klos
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I'll accept John Klos' observ

I'll accept John Klos' observations as good. Mac OS For those who don't lurk the NetBSD lists, John runs the fastest m68k machine running NetBSD, an Amiga 2000 w/ 68060@50MHz, IIRC. It's used to run native builds fo m68k based NetBSd ports, among other tasks. John gives a great service to the Open Source community! FWIW the Softfloat builds of NetBSD/m68k for 2.0 are gonna allow a whole new gaggle of Macs (and other machines..) to run NetBSD! I'd say dozens of models will gain support.

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Well, thank you for all of th

Well, thank you for all of those nice things you said!

Just for the record, I'm not running any A2000s (but I help someone who does); the fastest m68k machine I have is the Amiga 4000 with the CyberStorm MkIII. It has a 66.7 MHz m68060, 128 megs of 64 bit memory, and DMA UW-SCSI. Currently, it's not serving - it's being used to test NetBSD 2.0, which will be coming out soon.

My other primary Amiga would probably deserve a writeup in the hardware hacks / case mods section - it's an Amiga 1200 with a 60 MHz m68060, 256 megs of memory, and 10 MB/sec Fast SCSI-2. I've painstakingly built it into a 1U rackmount case, and it's currently colocated with my kick-ass PowerPC server here in Los Angeles. That one runs NetBSD 1.6.x and is serving the m68k-softfloat binary packages.

Both of them, in addition to both of my colocated PowerPC servers, are using Acard SCSI-IDE adapters. Never a problem!

John

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cool

Seeing the traffice this thread has garnered for the last few weeks, I feel preety confident that the Acard is the way to go for my Quadra. Now i just need to cough up the $70 (US) to get started with my first. That may take some time, but I will buy with confidence when I do.

Thanks to all who have posted thus far!

--DDTM

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Maybe this will help.

http://froogle.google.com/froogle?q=7720U&btnG=Search+Froogle&scoring=p

I've never regretted spending money on these because they can always be used with bigger IDE drive and in other computers. Good luck! I just ordered one so I can put a 160 gig drive in a Quadra 605...

John

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:o You're gonna be giving d

Shock You're gonna be giving danamania a run for the money.

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I thought that the 68k's only supported 6GB max

I have an LC 630 Dos, and the problem i have is that the machine only see's 2GB HDD's Max I was hoping to use the 4GB HD from my PowerComputing Tower in it and use it as a game machine. But if i stick the hdd in, it says something like "148TB" in the disk drive size window. It even does this when using OS 8.1 / does the 68k machine support more than 6GB?

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You can buy the 2.5" laptop d

You can buy the 2.5" laptop drive versions on Ebay for like $10 to $20. I have a couple. The way they work is that they will support a max of like 16384 cylinders, minus a few. That seems to make the maximum capacity about 8 gigs. I have played with a 40gb laptop drive, once I got it to format to 8gb. I got distracted before I ever put it into my pb 520. Search for "2.5 scsi" on Ebay.

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m68k IDE

Hi,

I can safely say that a Quadra / Performa 630 will support up to 128 gig drives, but you very likely have to partition it in another machine, then run an older Drive Setup and use the "update driver" option. Not sure what the size limit on the first partition needs to be if you want to boot, but it has to be HFS, not +, in order to boot.

I had an 80 gig IDE drive in a Quadra 630 for a while, and I don't remember how hard I tried to partition in using the 630, but Apple HD/SC, of course, doesn't run on IDE drives, and Drive Setup didn't work the way it was supposed to work, so I just stuck it in a PPC machine and partitioned it there.

John

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Largest drive in Q630...

...is at least as large as you can get. I have a 750 gig drive in one. Mac OS should be able to see at least 2 terabytes.