The Rejuvinator:
Upgrading the disk in a SCSI-based laptop

version 0.1

Keywords: scsi laptop, laptop scsi, powerbook 500 series, scsi powerbook, scsi-to-ata adapter, scsi-to-ata converter, scsi-to-ide adapter, scsi-to-ide converter, ata-to-scsi adapter, ata-to-scsi converter, ide-to-scsi adapter, ide-to-scsi converter.

The PowerBook 520c is a 68000-based laptop from 1994. Mine has a 25 MHz 68LC040 and 36MB of RAM, and had a 256MB disk. Besides plain nostalgia and tinkering, my excuse for keeping it is that I want to make sure I can read old 400K and 800K floppies and run programs from the 1980s. But that old hard disk was cramped.

Getting it out was easy enough. The keyboard comes off with two screws, revealing, from left to right, the old drive in its "sled," the compartment with all of the computer electronics, and the floppy drive:

The hard disk in the PowerBook 500 series is SCSI. These are the upgrades I considered:

External SCSI disk?

What's the fun of a small laptop anchored to a big drive with a stiff cable? It's undignified.

New SCSI internal disk?

You might think you could just buy a new plug-compatible SCSI drive for a laptop. Nope. In fact, for quite a long time, 2.5" SCSI drives weren't made at all. Just recently, at least one company has started making them again, not for laptops but for use in RAID arrays. However, these are in the $250 range at this point, and besides they have a different SCSI connector than the one in my PowerBook. Theoretically any SCSI drive can be connected to any SCSI bus with the appropriate connectors and wiring, but I didn't find an easy guide to this.

Old or used SCSI internal disk?

Back in the '90s, larger SCSI laptop drives must have been made, right? This is true, but they're hard to find. I finally found some model numbers by searching for the model number of the 256M disk: IBM (=Hitachi) DHAS-2270. Hitachi made both scsi and ata versions of its drives for a while, but they stopped around 1 or 2 GB. Also, the prices on the used market were in the hundreds of dollars.

From a couple sources I read of drives with Apple labels on them which were 1.3 GB ata drives with scsi converter cards. Now, having the Apple label is nothing to scoff at, since it means that the Apple disk formatting and partitioning utilities will agree to work with the drive. But 1.3 GB still seems a little small to me. Also I had heard that the converter Apple had used was of the old, slow generation, which is getting ahead of the story:

ATA disk with SCSI converter card...Bingo.

It took me two weeks of trying search strings until I found good information on this. There were apparently a slow generation of these converter cards followed by a fast generation. There were incomplete reports of experiences formatting converted drives using FWB Hard Disk Toolkit (what version??) and getting slow, or fast, or slow then fast results. Exact dimensions, connectors and form factors were hard to get details on. I was afraid that these converters wouldn't fit inside the PowerBook. The best single page of info during this whole project was macdan's "FAQ-of-sorts" on scsi converter cards.

(I located the manufacturer of the best-looking card, Century.co.jp, and ordered and recieved one from them. Because of what I paid for it, however, let's put that one aside.)

From macdan and another source I got the name of MCE Technologies, and emailing yielded a response from Arnie there saying that they had a bunch for $20 each, and that he would throw in a 10Gb ata drive for $10 extra! My biggest unused ata drive was 6GB, so I took him up on it. Contact information below.

So, the hardware

Here, from left to right, are the new ATA drive, the Century SCSI-to-ATA bridge card with its side rails on, the sled from the PowerBook, and the original 17mm thick SCSI drive.

The four are aligned to show how the screw holes line up between the ATA drive and the adapter rails and between the other set of holes on the adapter rails, the original SCSI drive, and the sled. Also, you can see the male ATA connector at the top of the ATA drive, the female "U-turn" ATA connector pair on the top of the adapter, and the male SCSI connectors on the bottoms of the adapter and the SCSI drive.

The sled is shown upside-down. The drive mounts on the visible underneath side (separated by a piece of translucent plastic). There is a tab on the sled that reaches down the side and hooks under a corner of the drive. The bottom of the hook touches two contacts on the bottom of the frame of the PowerBook--hmm.

Here's the top of the SCSI-to-ATA converter card. In this picture the U-turn connector is removed from the male ATA connector (now at the bottom of the picture). As you can see, the 2.5" in 2.5" drives is like the 2 in 2-by-4 boards: nominal. I've heard that it refers to the diameter of the actual disk.

Here's a closeup of the board with as much identification of the board and chips as there is. I've increased the contrast on two of the chip-tops. One says "USBATA," hmm, or maybe US8ATA. The cards from Century and from MCE were identical except for the serial numbers on the other side.

The adapter arrived with the rails attached to the PC board. In order to attach the rails to the ATA drive, they had to first be removed from the board. When the adapter is attached to a 9.5mm thick drive, the combination is under 17mm thick. Here are the sides of the original SCSI drive (top) and the ATA drive plus converter (bottom). Notice the slight difference in length.

The rails on the sides of the adapter are vertical. Horizontal tabs with holes stick inward at three levels. The ATA drive attaches to the top tabs, the adapter PC board to the middle, and the bottom tabs-- or holes in the sides of the rails-- are used to attach the whole assembly to the computer (in my case the sled) the way a SCSI drive would. In the closeup below you can see tabs on three levels, a bit of the converter PC board, and bits of screws holding the ATA drive and the PC board to the rail. Also you can see the vertical PC board that is the backbone of the U-turn connector. That thickness is how much longer the adapted ATA drive is than the SCSI drive.

(By the way, isn't there something wrong with the ruler being labeled "mm" but numbered by centimeters?)

Getting it formatted

I did a little preparing in advance. I found that the highest version of Mac OS that the PB 520c can run is 8.1. This is also the first version of Mac OS to support HFS+, which makes better use of disks bigger than, well 256M, actually. I don't believe the 520 can boot off an HFS partition.

The version of Mac OS on the 250MB SCSI disk was 7.5.3.

I had a scsi Zip drive, a scsi CD drive, and a Mac OS 8.1 install CD. Using these and various combinations of drivers (Iomega vs. not, Apple CD vs. Toast CD) and summersaults, I was able to boot from the CD and do a minimal install on a 100MB Zip disk. The install had taken three hours and was halfway through when I went to bed. But it succeeded by morning.

Then I plugged the Zip into a Wallstreet Powerbook and made a disk image.

At first the PB 520c wouldn't boot from the Zip. I think the magic that got it to go was: format with FWB (this left enough space for the drivers), install drivers using Silverlining (which crashed in the process), then copy the disk image from the Wallstreet back to the Zip.

I also made an image of the old scsi OS 7.5.3 disk with all its apps and files, by booting from the Zip and connecting by AppleShare / AFP / File Sharing to the Wallstreet (which could only be done with the Wallstreet booted in OS 9).

When the new ata disk arrived, I tried various combinations of Silverlining, FWB Hard Disk Toolkit (version 4.5), and pdisk (both the OS 9 and OS X versions) to partition it and install the necessary drivers. Nothing seemed to do the trick; the volume wouldn't mount on the PB 520c.

I was about to embark on another two-week web and email search for the right versions of FWB HDT or Silverlining, or for hacks to Apple's utilities, when it occurred to me to use OS X's Disk Utility.

For this, all I had to do was, plug the ata drive into an external usb/firewire enclosure I had (these things are great!), plug my USB PCMCIA card into the Wallstreet, boot it in OS X (version 10.2.8) and run Disk Utility, which let me do just what I wanted: make three partitions (two small HFS boot partitions and one big HFS+ partition), and install the "OS 9" disk drivers.

Then I copied the OS 8.1 image onto the first partition, reassembled all the hardware, and...it booted!

The only benchmark I had was a timing test inside Silverlining. The test alternates reading and writing. It's meant to test data throughput for the bus; maybe it reflects something about latency getting to the disk. Here are the results from the original SCSI disk, a 240MB IBM DHAS-2270 with Apple part # 655-0104 A...

...and for Arnie (Arnie Ramirez, I have named my first partition after you), a 10GB Toshiba MK1016GAP, aka HDD2152, Apple part # 655-0842:

Here are the "Get Info" screens for the three partitions I set up on Arnie. Because of HFS ("Mac OS Standard"), the allocation block size-- the smallest file size-- on "Arnie Boot" is 12.5K. On HFS+ ("Mac OS Extended," e.g. on Arnie Space) it's 4k.

Only one problem...

I noticed that copying data was somewhat slow. For instance, restoring the 200MB OS 7.5 image took a while over AFP. Also, downloading things off the web (over DSL) seemed slow (forgot to include the iCab chapter of the story). The bottleneck turned out to be the disk itself. Duplicating a 250MB file took 25 minutes, which is 167KB or 333KB/sec. depending how you count, but a little slow.

I tried overwriting Apple's drivers using my copy of Silverlining. Oops. I think it tried to readjust the partition boundaries before it crashed, so at the moment the disk is unusable and I'm on a search for a more appropriate version of FWB HDT, Silverlining or some substitute.

Links (unsorted):

The best single source of information for this project was macdan's "FAQ-of-sorts on the subject of IDE-SCSI adapters, with specific interest in adapters for 2.5" drives in early SCSI-based Apple PowerBooks." Says the Century card supports up to 32GB drives.
PowerBook HDs and SCSI - ATA adapters

MCE Technologies sells the Century card for $19.00 (but during a website update they seem to have dropped the link to the specific page).
MCE Technologies
I ordered the card and the 10GB Apple-brand ATA drive from Arnie Ramirez there.

Century's page about their card. 11,000 Yen for a sample. Includes picture.
2.5" IDE>SCSI INTERNAL CONVERTER KIT [Type CHB-25INT]

Disappointing results with an Apple 1GB converted IDE drive, then says there are "now" 4 and 6 GB drives with "extremely fast," "3rd generation" converter cards, $400 and $480 from MCE, Mac Components Engineered
PowerBook 500 w/ Apple 1GB converted IDE drives

Info about the PB 500 series. Says large capacity SCSI disks "are increasingly difficult to find. However, if you can find one, System 7.5.5 will support up to 4GB. " System 8.1, the highest supported by the PB 500, supports and much bigger disks. Also, 7.5.5 supports small partitions on a big disk.
pb500.html

This one is a table showing of PowerBook drive types, maximum drive heights, and maximum supported drive capacities.
PB 500 series: SCSI, up to 19mm, no capacity limit in SCSI controller.
IGM - PowerBook Hard Drives: The Essential Upgrade

Page at ACARD.com about one of their 2.5" SCSI-IDE bridges, with picture.
ACARD Products - IDE/SCSI/SATA RAID Storage Solutions

MemoryExpoUSA offers both 2.5" and 3.5" SCSI-to-IDE bridges
"SCSIDE Cabinet"

One person's experience with an ACARD bridge for 3.5", 1" thick drives in a desktop Mac.
ACARD-Apple Drive Setup

A short conversation between Macdan (see above) and someone else, about disappointing speed results with some converter cards. Includes a copy of Macdan's "FAQ-of-sorts".
Interesting SCSI/IDE tests (Duo 2300)

Page at ADTX.com about their converter cards. Includes picture. "ADTX welcomes OEM requests. SCSI-IDE Converter Card Supports all IBM HDDs, other HDDs can be supported to meet your requirements." Okay I'll pass for now.
ADTX SCSI/IDE adapter cards

Missing: SCSI FAQ which says that all SCSI busses are forward and backward compatible with all SCSI devices, but not how to connect, e.g., a 66-pin device to a 50-pin bus.

Missing: Recent 2.5" SCSI disk for RAID, $350.

Missing: Model numbers and suppliers of used SCSI 2.5" disks with greater than 256M capacity. These also are in the $300 to $800 range-- I imagine these being sold to sysadmins who won't buy anything but exact replacements.

Missing: Page about Apple HD SC Setup and Drive Setup, which versions have which bugs and features, and how to hotwire them to work with non-Apple drives.

-- Steve Witham < ess double-u at tiac not_this dot net >