30 years of Mac storage

Having bought the original Apple II in 1978, I was impressed with Apple's engineering, though the $600 144k floppy was too rich for my wallet. So a portable Panasonic cassette deck was my first "mass storage" device.

Joining the computer industry at DEC in 1981, I followed with avid interest the development of the PC market and expecially the Mac from then on. I realized early on that for most applications I/O speed and storage capacity were more important than CPU MHz, an insight that shaped my career.

Compact Macs
The original Mac storage was woefully underconfigured - 128k RAM and a 400k Sony floppy - especially given the $2500 price. You could barely fit the system software and an app on the floppy, and the limited motherboard RAM gave little room for that tiny app to much.

Later in 1984 the Mac got upgraded to 512k - for an extra $200 - but the 400k floppy remained and there was no hard drive option. Though I was impressed by the Mac concept, I didn't find the 512k compelling.

It was the 1986 Mac Plus that incorporated expandable storage and became, IMHO, a useful system rather than an overpriced toy. Standard 1MB RAM, expandable to 4MB using 30-pin SIMMs - although you had to clip a resistor lead to use them - meant much larger apps and data sets could be handled in memory. The 800k floppy was large enough for the system and several apps.

But the big advance was the SCSI port that was a Mac feature for the next 13 years. You could easily add 10s of megabytes of fast - 5MB/sec! - mass storage to a Mac. In theory up to 6 external devices, which besides disks could include scanners, CD-ROMs and, later, Zip drives could be added to the fiddly, termination-required, SCSI bus.

The Mac Plus, with an external 30MB drive, was my first Mac.

It wasn't until 1987 and the Mac SE that you could get an internal hard drive - 20MB - or dual floppies for almost $4k. In 1989 the Mac SE FDHD offered an internal 40MB drive, still with a standard 1MB of RAM.

But the compact monochrome Macs reached their apogee with the Mac SE/30, the first Mac with a 16MHz, 32-bit CPU and data path, and the - seldom used - capability to install 128 MB of RAM - larger than the optional 80MB hard drive and more costly than the SE/30!

The Mac II family
1987 saw the arrival of the first "open" mac: you could open it up to add memory and cards to 6 NuBus slots. Its Color QuickDraw supported 16.7 million colors, so suddenly you needed VRAM: up to 512k!

But the minimum standard RAM remained at 1MB, a woeful underconfiguration, and a pattern that the Mac would repeat for the next 25 years.

On the plus side, the Mac began its early adoption of CD-ROM drives, which didn't become standard until the 68040 Macs. If you ever loaded Microsoft Office from 20-some odd floppies, this was a huge advance. CDs were cheap, light, small and capacious.

But the Mac also experimented with high-end memory technology. The $10k Mac IIfx used special 64-pin high-speed 80ns dual-ported SIMMs. With 8 slots the fx could be expanded to 128MB with uncommon and hyper-costly 16MB SIMMs.

The Mac II family traversed the uncomfortable transition from 16 to 32 bit memory addressing, virtual memory with System 7 and external to internal memory management units. As with the Intel PCs, this meant memory upgrades were often much more complex than today's machines.

68040 Macs
With clean support for 32-bit addressing in the 1991 Quadras, memory was a much simpler, though still costly, ugrade. Apple also started shipping 400MB+ drives. But Mac engineers started looking elsewhere to keep Macs compeitive.

The biggest change was in the lower-cost 1994 Quadra 630, the first Mac to use an internal IDE drive. IDE ruled the PC world and their volumes made them half the cost of SCSI, although Apple wisely retained the external SCSI for compatibility.

The Quadra 950 had a record 16 SIMM slots, enabling up to 256MB of RAM. But at $25 per MB in 1993, few ever filled them.

PowerPC Macs
The confusing plethora of PowerPC Macs had few storage advances, though VRAM sizes grew and standard RAM reached 64MB on some models. Apple was sinking fast and was on the edge of failure when Steve Jobs returned in 1997.

Standard hard drive sizes passed 1GB in 1995 and some models saw 24x CD-ROMs. HFS+ was introduced in 1998.

During this time the very first Firewire 400 ports crept into the lineup as build-to-order options. Much faster and less fiddly than SCSI, with a smaller connector and theoretically supporting up to 63 devices, FireWire ultimately replaced the long-serving SCSI port beginning with 1999's Power Mac G3 350.

The Jobs era
Some great storage advances were made by the Mac during Steve's last stint at Apple, but some was lost too. Here are some highlights:

• SCSI abandoned in favor of IDE and later SATA drives
• Macs embraced and then abandoned Fibre Channel as well as the first 21st century file system, ZFS
• Macs pioneered Thunderbolt, a faster and more stable alternative to USB 3.0
• iMac standard drive capacities grew from 4GB to 1TB
• In 2008 the MacBook Air became the first major PC to ship with an SSD, and all Macs have led the market in SSD adoption
• The underfeatured Xserve RAID was introduced in 2003 and discontinued in 2008, partly to free up engineering resources for iProducts
• Adopted a cluster file system - Xsan - based on the widely used StorNext File System from Quantum, which is now embedded in the $20 OS X Server.
• Inline memory compression on OS X Mavericks has significantly reduced memory requirements
• Mac abandoned the external storage market, forcing customers to rely on 3rd parties for arrays and external drives

The Storage Bits take
While I chide Apple on their costly RAM and flash memory, and their chronic system underconfiguration, they've been been innovators in important ways. From SCSI to virtual memory, from Fibre Channel to Thunderbolt, from Xserve to Fusion Drive, they've pushed the PC envelope.

Let's hope the next couple of years sees a replacement for the antiquated and unreliable HFS+ file system. The technology is out there and will be a key indicator to the Mac's future - as in, does it have one?

Comments welcome, as always. What's your favorite thing - or rant - about Mac storage? Update: Added FireWire info.