Mac-Compatible Hard and CD-ROM Drives, Cases - tech info

Directions

This page last updated April 30 2020 but has not had major editing since 2010. This Web page provides a lot more detail about SCSI versus IDE, descriptions of hard drives and CD-ROM features. If you just want drives to buy and prices, go to this page. Sorry if you have to jump around between pages.

When ordering, please follow this link for ordering information, terms and conditions, and info about orders outside the USA. We will also provide brief instructions when you order.

Introduction

We sell several kinds of hard drives and CD-ROM drives for your Mac. Our drive sales page is at this link. On this page, we provide some technical descriptions and discussions. Go to our sales page see our inventory and to get prices for specific items. (We also have a few customers with older music synthesizers or samplers: check this section for details.

We sell drives, but we don't offer "how to install" instructions or technical assistance beyond the notes on our Web site. You can check our brief tech notes if you need a bit of technical explanation. But we also suggest you check the Web: the major drive manufacturers have Web sites with a LOT of info, including some "how to" information. A Web search for "SCSI drive install how to" will be informative. Also a Web search on the drive by manufacturer and model name and number will likely find all the tech info on that drive.

If all these selections, terms and features are confusing to you, just explain to me via email and please tell me what drives you are using or plan to connect to your Mac, and what model Mac you have, and what operating system version. I can describe what I have. Please note: all offers are subject to availability; ask what we have in stock but it helps if you can specify your drive needs by price, capacity and/or type of drive.

When ordering, please follow this link for ordering information, terms and conditions, and info about orders outside the USA. We will also provide brief instructions when you order.

• drives technical details section
• floppy drives & diskettes are on another page..
• Internal hard drives
  • Internal SCSI hard drives
  • Internal IDE hard drives
• CD-ROM drives and comments
  • internal CD-ROM drives
  • external CD-ROM drives
• Iomega ZIP drives
• External SCSI hard drives
• External SCSI-1 cases
• External drives 25 pin SCSI
• Mac NuBus and PCI SCSI controller cards
• SCSI cables and terminators
• CD-ROM caddy or caddies
• drive sleds, rails, carriers, mounting hardware
• Music samplers, synthesizers
• Apple brand HD20 and HD20 SC drives
• External SCSI hard drives, other brands
• See this Web page for descriptions of SCSI connectors.
• repairing hard drive stickiness?

Please note We can only provide a limited amount of information here to assist our customers, It is up to you, the customer to determine your hard drive needs. We try to answer some common questions here, but we can't be responsible if it is incomplete or in error. We would appreciate any corrections.

Brief Tech Summary

Most older Macs used SCSI hard drives until the G3 and later Macs wich used IDE or ATA hard drives. Apple also used IDE internal hard drives in some Quadras and Performas. External hard drives are almost all SCSI, not IDE (until the much later FireWire or USB external drives.) A simple way to determine if a drive is SCSI or IDE is to count the pins on the connector to the large flat cable; SCSI drives have 50 pins, two rows of 25, IDE drives have 40 pins, two rows of 20. Here's a picture of a SCSI hard drive and its connector. Note that all older Macs with CD-ROMS used SCSI CD-ROM drives, even the Macs which also use IDE hard drives.

Most older Macs use a DB-25 connector to external SCSI devices (primarily hard drives): it is on the back of the computer. Many older external SCSI devices use a SCSI-1 connector, also called a Centronic 50-pin connector. Here is a typical cable used to connect the two.

Our internal SCSI drives are compatible with most older Macs, and tested for proper startup, good operation on a Mac, and are Mac initialized (formatted). Most of our external SCSI cabinets are generally low, flat cabinets about ten inches by ten inches and a few inches tall. Larger cabinets are available. Most of our external drive cabinets have extra AC outlets, so the external drive's AC power switch can also switch other AC devices.

Please note: the cabinet is just a box for the drive or CD-ROM; Many of our external SCSI cabinets are not made by Apple but it is the SCSI drive inside which must be compatible with your Mac.

See the notes below for more discussion of SCSI and IDE drives, termination, the HD 20 series, and other features. Also, most of the images on this page are linked to larger images, click on them to see more details. If these selections and features are confusing to you, just explain to me via email what drives you are using or planning to connect to your Mac, what model Mac you have, and I can describe what I have. Please check our terms and conditions section for our terms of sale.

SCSI drives

See this Web page for descriptions of SCSI connectors.

IDE drives

CD-ROM SCSI drives

SCSI Termination

A SCSI terminator may be used on external drives to reduce noise on the SCSI cable bus. You can get these as a small external device that connects to the 50-pin SCSI connector on an external drive.

Older hard drives can otherwise have optional terminating resistors on them, which can be removed if more drives are added to a SCSI system. These terminating resistors are two or three little resistor packs with several (8 to 11) "legs", located near the SCSI connector on the circuit board of the hard drive. These are called "SIP resistor packs", and are of a specific resistance value. If they are not there, you may have a row of little socket pins.

Newer hard drives have what is called "active termination". The termination is NOT a set of resistors, it is circuitry on the drive which must be "disabled" or "enabled" via a jumper block. There is typically a jumper position on the drive labled "term enable": leave the jumper ON to enable termination, OFF to disable it.

If you use the drive as the ONLY drive on a SCSI cable (internal or external), or at the END of that cable, then the terminator on the drive must be enabled or installed. If you use this drive with other drives on a cable and it is NOT at the end of the cable, the terminator must be disabled or removed.

More info about drive jumpers can generally be found by a Web search for that brand and model drive: most manufacturers provide data sheets online. Also see my "drives" sales page about "jumpers".

Note on Mac Plus and SCSI: Mac Plus drives must use "passive termination" on SCSI drives. The Plus has no internal hard drive, but has a SCSI controller and the Apple DB-25 SCSI external connector. The last device on the "chain" of SCSI devices must have a passive or resistive termination. As noted above, these are often SIP resistor packs, which can be added or removed. The reported issues about this, range from intermittant problems to physical damage from DC power (for the active terminator).

SCSI connectors

See this Web page for descriptions of SCSI connectors.

Hard drive SCSI addressing

The SCSI address of the drive is set by three jumpers locations. A jumper is a pair of pins on which a little device is placed, typically a very small black cube, which shorts the two pins together. SCSI drives inside the Mac are typically set at address zero, which is no jumpers. External drives are usually at address 2 or 3 or 4. A jumper placed in the center of the three jumpers will set the address to 2.

Many external SCSI drives have a SCSI address switch. This is usually a device with numbers that change when you press a button. These numbers, 0 through 7, are SCSI addresses. This switch must be connected to the SCSI drive via a cable to a connector. There is no standard for this connector, different models of SCSI drives have different ways to make this connection. It may be easier to use jumpers to set the SCSI drive to one address, than to accomodate the SCSI selector switch. For many users, they set the SCSI address once and forget about it, usually to address 1, 2, 3 for external drives. (Internal SCSI drives are always set to address 0.)

Do you have a SCSI accessory that tells you what devices are at what SCSI address, and does it see the drive? System 6 had a simple one that showed a table of all SCSI devices and the CPU at address 7. Make sure of course the drive is not set to SCSI address 7!

jumpers for SCSI addressing, other feature selections

See my "drives" sales page about "jumpers". There's specific information and photos about the "jumpers" used on SCSI drives for SCSI addressing or other selection of features.

Hard drive sounds

When you start up the hard drive, you should hear it "spin up" and come up to speed. After starting up, you can hear the drive "seeking" when it moves the drive heads back and forth. These actions occur even if the drive is powered up without a computer connected to it. But the drive will not do further "seeking" after powering up without a computer running it.

It may be hard to hear the drive over the fan inside the computer. If your drive is not working, you may be able to determine it is the problem if you don't hear the drive spin up.

Buying hard drives, other drives

Mac HARD DRIVES, CD-ROM drives and other drives are sold on this linked Web page.
This page has terms and conditions for ordering, payment, etc.
...and back to the Mac stuff Home page.

I have internal hard drives available for the Mac, from 80Mb to a few Gigabytes. They fit inside your Mac and hold files and folders and programs; don't confuse hard drives with memory. The older Macs use SCSI internal hard drives, the more recent Macs use IDE or EIDE hard drives: know what YOUR Mac uses before you order. If you need some explanation about "SCSI" or "IDE", please check my brief Tech notes. All SCSI drives have a 50-pin flat cable connectorl the IDE drives use 40 pins.) These hard drives measure 4 inches wide, about 6 inches long, and about an inch tall (unless noted) and are generally called "3.5 inch drives". Laptops use smaller "2.5 inch" drives, check my Mac laptop section for stocks of those.

Internal Mac-formatted SCSI hard drives

Shipping weight 2 lbs for one drive, add one pound per additional drive. "1.5 inch tall" drives are a little taller physically; some Macs don't have the extra space needed but most do. We price them a little lower but they can perform well. All drives are tested and formatted on Mac equipment, we may be able to test them on YOUR model if you inform us. Some older Macs may not work with more recent SCSI drives above about 500MB, because newer drives use "SCSI active termination"; ask for details. All drives subject to availability but we have good stocks of drives below 1GB.

Some Macs require a sled or bracket to attach the hard drive to the Mac cabinet. Specify your Mac model and we can generally identify what you may need to attach and connect the drive. Check my sled and caddy section for prices and descriptions. But if you are replacing an internal drive, you can reuse that hardware and cabling.

Prices and sizes of SCSI internal drives are on another page.

Internal Mac-formatted IDE drives

Shipping weight 2 lbs for one drive, add one pound per additional drive. All drives are tested and formatted on Mac equipment, we may be able to test them on YOUR model if you inform us. Some Macs require a sled or bracket to attach the hard drive to the Mac cabinet. Specify your Mac model and we can generally identify what you may need to attach and connect the drive. Check my sled and caddy section for prices and descriptions. But if you are replacing an internal drive, you can reuse that hardware and cabling and sled. If you want a specific brand and model number of drive, we charge an additional $5, of course assuming we have that particular drive in stock.

Prices and sizes of IDE internal drives are on another page.

Sleds, rails, brackets for internal drives

Prices and types of sleds, rails, etc. are on another page. Check there and specify your Mac model when you order. Check the info below if you are not sure what these are.
PLEASE SPECIFY a Mac computer model when ordering these, not an Apple part number.

When ordering, please follow this link for ordering information, terms and conditions, and info about orders outside the USA.

SCSI connectors

See this Web page for descriptions of SCSI connectors.

CD-ROM drives information

The CD-ROM drives I sell are used, tested, and pulled from other Macs. The internal drives are intended to be replacement drives and do not include cables, mechanical parts, and additional OS system CD-ROM extensions - I sell some of those seperately. External CD-ROM drives will need a SCSI cable and generally a SCSI terminator, which we can provide at additional cost. Prices for CD-ROM drives, caddy or caddies, and trays to hold the drives are listed on my drives Web page.

Some of the older CD-ROM drives require a caddy, which is a plastic box that you insert the CD-ROM disk into, then the caddy goes into the drive. Here's one of those caddy-supporting CD-ROM drives. "Caddyless" drives have a tray that pops out of the drive, you lay the CD disk onto the tray and it retracts into the drive.

CD-ROM caddies are priced on another page. You do not need caddies with tray-type CD-ROM drives.

Because some early Macs used CD-ROM drives with either caddies or trays, some Macs have different case panels or bezels, with slots of different sizes to accomodate either a caddy-drive or a tray-drive. Here's a photo of two PowerMac 7100 bezels, one for each type of CD-ROM drive. The wider-slot is for the tray; the narrow slot is for a caddy.

The speed of a CD-ROM drive is described as a multiple of the speed of an audio CD: "2x" means twice as fast, "8X" eight times as fast, etc. For many older Macs, an older or slower CD-ROM drive is adequate; many of these Macs do not have the performance or features to take advantage of faster CD-ROM drives. Note: the Apple CD150 external drives (1X speed) may not provide audio via the SCSI connector to your Mac; these drives are probably best used with Compact Macs and other older Macs without extensive audio capabilities.

Apple used the following SCSI external CD-ROM models, with CD-ROM drives inside them.
Don't be confused. The drive case has a model name; the CD-ROM drive inside has a brand and model too.
for the CDSC: Sony CDU-8001 caddy-based CD-ROM drives
for the CD SC+: Sony CDU-8002 caddy-based CD-ROM drives
for the CD150 (1x): Sony CDU-8002, Sony CDU-541-25 caddy-based CD-ROM drives
For the CD300 or 300i (2X): Matshita CR-8004; Sony CR-503C, Sony CR-503K;
- also Sony CDU-561-25 AKA CDU-8003 caddy-based CD-ROM drives.
for the CD600 or 600i (4X): Sony CDU-75S with an internal tray.
for the CD300e: ?
for the CD600e: ?
for the CD300 plus: ?
for the CD600 plus: ?
I have not identified every internal drive for each Apple external CD-ROM model. Sorry.

If you are upgrading a Mac with a faster CD-ROM drive, please note that System 7 only recognizes a limited number of Apple drive models. CD-ROM drives such as the 8X or 12X drives were sold AFTER System 7, and so these drives may not be recognized as "Apple" drives by System 7. There are some "aftermarket" or "third party" software programs which allow Macs to use non-Apple drives, including packages which were sold with drives by other companies. Those software packages MAY, or MAY NOT, recognize the later Apple drives. There was an article about Apple's CD-ROM support in "C't Magazine" years ago; as of Sept 2005 a copy of that article is on this Web site. The article is by Andreas Beier, "The MacOS & third-party CD- and DVD-ROM drives".

Prices and sizes of internal CD-ROM drives are on another page.

Prices and sizes of external CD-ROM drives are on another page.

CD-ROM caddies are priced on another page. You do not need these with tray-type CD-ROM drives.

Here's an older Apple product: AppleCD SC model M2850 is apparently an early Apple external CD drive. It uses the Sony CDU-8001 or 8002 drive. It requires a caddy but is older and larger than the CD150 above. I have a few of these: check our Mac collectables section for details.

Follow this link for SCSI cables.

Iomega ZIP drives are on another Web page. We have external and internal ZIP drives of many kinds.

The last several years (2014) have been the last use of ZIP drives. I've been asked about ZIP drives versus CD-writing drives so much, I wrote something up. Here's some "advice" about ZIP and CD-ROM drives.

When ordering, please follow this link for ordering information, terms and conditions, and info about orders outside the USA.

Apple brand external hard drives

These cases are described and priced on another page.

See this Web page for descriptions of SCSI connectors.

When ordering, please follow this link for ordering information, terms and conditions, and info about orders outside the USA.

External SCSI drive, 25-pin connector, no AC outlets

SCSI-2 cabinets, drives

note: my SCSI-2 cabinet list has been moved to my SGI/Sun/DEC Web page.

Music samplers, synthesizers

We discuss Roland sampler use of Apple SCSI drives on another Web page. Some of those samplers also use Apple CD-ROM SCSI drives. I can't test drives on a sampler but I test drives on Mac computers.

Apple HD 20 (floppy connected) hard drive