code names: Erickson, Raffica, Raffika, Ray Ban, Spin, Oceanic
The IIsi shares some features with the SE/30, some with the LC series, and some with the Mac II series. Like the SE/30, it has a 68030 PDS (Processor Direct Slot) for expansion. Like the LC, it has no built-in NuBus slot, is quite short, and has a curved front. But with an adapter, the PDS can be converted to a NuBus slot, making it a legitimate member of the Mac II family (all other members of the Mac II family have built-in NuBus slots).
- Got a Mac II or other vintage Mac? Join our Vintage Macs Group or Vintage Macs Forum.
- Our System 6 List and System 6 Forum are for those using Mac System 6.
- Our System 7 Forum is for those using Mac System 7.
The IIsi was designed as a less expensive, less expandable alternative to the Mac IIci. Cost saving measures included eliminating NuBus expansion slots, soldering 1 MB of RAM to the motherboard, and using a slower CPU (20 MHz vs. 25 MHz). Although the IIsi was marketed as a 20 MHz computer, users quickly discovered it used parts rated at 25 MHz. (Apple had intended it as a 25 MHz computer, but chose to scale back the speed to avoid cutting into IIci sales.) Chipping the IIsi to 25 MHz – or even 28 MHz – is not unusual.
Like the IIci, the IIsi uses onboard RAM for video, which slows the computer slighty. One way to speed things up is to add either a PDS or NuBus video card (see our NuBus Video Card Guide for more information). Another is to set aside the first 1 MB of RAM, since that is the bank shared for video and program space. This can be done by creating a large-but-slow 768 KB disk cache or using IIsi-RAM-Muncher by Paul Ripke. (Note that this program is worthless if you’re using virtual memory or RAM Doubler.)
Along with the LC, the IIsi was one of the first Macs with audio input.
The IIsi is noted for a sound problem where the internal speaker may fail to sound. This is caused by poor contact between the speaker wire and the plug on the motherboard. This can usually be fixed by cleaning and coating the contacts on the motherboard with electrical cleaner and lubricant.
There is a ROM SIMM slot on the Mac IIsi which may be filled with a IIsi ROM, although this is rare, since the IIsi generally has ROMs on the motherboard. If you have a IIsi with this ROM, the computer will not function without it. There are mixed reports from the field concerning compatibility of the IIsi ROM with the SE/30; installing a IIsi ROM may make an SE/30 32-bit clean.
Although a nice computer, the IIsi was less than it should have been, so we call it a Limited Mac.
- introduced 1990.10.15 at $3,800; discontinued 1993.03.15
- part no.: M0360
- Gestalt ID: 10
- requires System 6.0.6 to 7.6.1
- addressing: 24-bit or 32-bit
- CPU: 20 MHz 68030
- FPU: 68882 (optional with NuBus adapter)
- ROM: 512 KB, usually soldered to the motherboard, occasionally on a DIMM
- RAM: 1 MB on motherboard, expandable to 65 MB using a 4-SIMM bank of 100ns 30-pin memory; can use 256 KB, 512 KB, 1 MB, 2 MB, and 4 MB SIMMs (you can use 8 MB and 16 MB SIMMs, although Apple does not officially support them)
- L2 cache: none
- 2.9, relative to SE
- 5.0 MIPS
- 3.84, Speedometer 3.06
- 0.24, Speedometer 4
- see Benchmarks: IIsi for more details
- built-in 8-bit video, supports 512 x 384 and 640 x 480 at 8-bits or portrait monitor (640 x 870) at 4-bits (uses 64-320 KB of RAM for video, not separate VRAM)
- video port: DB-15
- hard drive: 40 or 80 MB SCSI
- floppy drive: 1.4 MB double-sided
- floppy connector on back of computer
- ADB ports: 2
- serial ports: 2 DIN-8 RS-422 ports on back of computer
- SCSI ports: DB-25 connector on back of computer
- sound: 8-bit stereo
- audio in: 8-bit mono
- SE/30 PDS slot (runs at 20 MHz, so not all SE/30 cards will work – can be converted to NuBus slot with adapter)
- NuBus slot with adapter in PDS, supports 7″ cards, 12″ cards may fit with a slim hard drive
- size (HxWxD): 4.0″ x 12.4″ x 14.9″
- weight: 10 lbs.
- PRAM battery: 3.6V half-AA
- power supply: 160W
- Guide to the Macintosh II Series, an overview of the Mac II family.
- Low End Mac’s best classic Mac OS deals. Best online prices for System 6, 7.1, 7.5.x, Mac OS 7.6, 8.0, 8.1, 8.5, 9.0, 9.2.2, and other versions.
- Know your Mac’s upgrade options, Phil Herlihy, The Usefulness Equation, 2008.08.26. Any Mac can be upgraded, but it’s a question of what can be upgraded – RAM, hard drive, video, CPU – and how far it can be upgraded.
- Creating Classic Mac boot floppies in OS X, Paul Brierley, The ‘Book Beat, 2008.08.07. Yes, it is possible to create a boot floppy for the Classic Mac OS using an OS X Mac that doesn’t have Classic. Here’s how.
- The compressed air keyboard repair, Charles Moore, Miscellaneous Ramblings, 2008.07.24. If your keyboard isn’t working as well as it once did, blasting under the keys with compressed air may be the cure.
- A vintage Mac network can be as useful as a modern one, Carl Nygren, My Turn, 2008.04.08. Old Macs can exchange data and share an Internet connection very nicely using Apple’s old LocalTalk networking.
- My first Mac was older than me, Alexander (Sasha) Ivanoff, My First Mac, 2007.12.19. It all started with a Macintosh IIsi from 1990, which was great for ClarisWorks and playing games.
- Vintage Mac networking and file exchange, Adam Rosen, Adam’s Apple, 2007.12.19. How to network vintage Macs with modern Macs and tips on exchanging files using floppies, Zip disks, and other media.
- Vintage Mac video and monitor mania, Adam Rosen, Adam’s Apple, 2007.12.17. Vintage Macs and monitors didn’t use VGA connectors. Tips on making modern monitors work with old Macs.
- Getting inside vintage Macs and swapping out bad parts, Adam Rosen, Adam’s Apple, 2007.12.14. When an old Mac dies, the best source of parts is usually another dead Mac with different failed parts.
- Solving Mac startup problems, Adam Rosen, Adam’s Apple, 2007.12.12. When your old Mac won’t boot, the most likely culprits are a dead PRAM battery or a failed (or failing) hard drive.
- Why you should partition your Mac’s hard drive, Dan Knight, Mac Musings, 2008.12.11. “At the very least, it makes sense to have a second partition with a bootable version of the Mac OS, so if you have problems with your work partition, you can boot from the ‘emergency’ partition to run Disk Utility and other diagnostics.”
- Better and safer surfing with Internet Explorer and the Classic Mac OS, Max Wallgren, Mac Daniel, 2007.11.06. Tips on which browsers work best with different Mac OS versions plus extra software to clean cookies and caches, detect viruses, handle downloads, etc.
- Simple Macs for simple tasks, Tommy Thomas, Welcome to Macintosh, 2007.10.19. Long live 680×0 Macs and the classic Mac OS. For simple tasks such as writing, they can provide a great, low distraction environment.
- Interchangeabilty and compatibility of Apple 1.4 MB SuperDrive floppy drives, Sonic Purity, Mac Daniel, 2007.09.26. Apple used two kinds of high-density floppy drives on Macs, auto-inject and manual inject. Can they be swapped?
- Vintage Macs provide a less distracting writing environment, Brian Richards, Advantage Mac, 2007.09.18. A Mac OS X user finds an old Macintosh IIsi and discovers the joy of writing undisturbed by music, messaging, and streaming content.
- The ultimate writing machine: Quiet and free of interruptions, Andrew J Fishkin, Best Tools for the Job, 2007.09.20. For creative writing, turn off messaging, use a quiet computer, and reduce clutter on your screen. An old computer may be your best choice.
- Moving files from your new Mac to your vintage Mac, Paul Brierley, The ‘Book Beat, 2006.06.13. Old Macs use floppies; new ones don’t. Old Macs use AppleTalk; Tiger doesn’t support it. New Macs can burn CDs, but old CD drives can’t always read CD-R. So how do you move the files?
- Chipping the Mac II Series
- Output Enablers 25-27.5 MHz clock accelerator
- MicroMac Speedy variable speed oscillator (to 30 MHz)
- MicroMac Diimo/030 (50 MHz 68030), 64 KB cache, optional 50 MHz 68882 FPU
- MicroMac Carrera (33 MHz and 40 MHz 68040), optional 128 KB cache
- MicroMac 90 MHz Carrera (45 MHz 68040)
- Sonnet Technologies Presto 040 (40 MHz 68040 or 68LC040), optional 128 KB cache
- Daystar Turbo 040 (33 MHz, 40 MHz 68040), discontinued
- Daystar Turbo 601, 66 MHz and 100 MHz versions, discontinued (resource: Unofficial Turbo 601 Site)
Discontinued accelerators (68030 unless otherwise noted) include the Applied Engineering TransWarp (25, 33 MHz 68040), DayStar Universal PowerCache (33, 40, 50 MHz), Fusion Data TokaMac SX (25 MHz 68040), Logica LogiCache (50 MHz), TechWorks NuBus (33 MHz 68040), and Total Systems Magellan (25 MHz 68040).
- Getting high off our own supply, RetroMacCast, 2007.06.05. James and John look at the Macintosh IIsi and the Spectre GCR Mac emulator for Atari ST computers.
- Mac System 7.5.5 can do anything Mac OS 7.6.1 can, Tyler Sable, Classic Restorations, 2007.06.04. Yes, it is possible to run Internet Explorer 5.1.7 and SoundJam with System 7.5.5. You just need to have all the updates – and make one modification for SoundJam.
- Appearance Manager allows Internet Explorer 5.1.7 to work with Mac OS 7.6.1, Max Wallgren, Mac Daniel, 2007.05.23. Want a fairly modern browser with an old, fast operating system? Mac OS 7.6.1 plus the Appearance Manager and Internet Explorer may be just what you want.
- Format any drive for older Macs with patched Apple tools, Tyler Sable, Classic Restorations, 2007.04.25. Apple HD SC Setup and Drive Setup only work with Apple branded hard drives – until you apply the patches linked to this article.
- Making floppies and CDs for older Macs using modern Macs, Windows, and Linux PCs, Tyler Sable, Classic Restorations, 2007.03.15. Older Macs use HFS floppies and CDs. Here are the free resources you’ll need to write floppies or CDs for vintage Macs using your modern computer.
- System 7 Today, advocates of Apple’s ‘orphan’ Mac OS 7.6.1, Tommy Thomas, Welcome to Macintosh, 2006.10.26. Why Mac OS 7.6.1 is far better for 68040 and PowerPC Macs than System 7.5.x.
- 30 days of old school computing: No real hardships, Ted Hodges, Vintage Mac Living, 2006.10.11. These old black-and-white Macs are just fine for messaging, word processing, spreadsheets, scheduling, contact management, and browsing the Web.
- Jag’s House, where older Macs still rock, Tommy Thomas, Welcome to Macintosh, 2006.09.25. Over a decade old, Jag’s House is the oldest Mac website supporting classic Macs and remains a great resource for vintage Mac users.
- Mac OS 8 and 8.1: Maximum size, maximum convenience, Tyler Sable, Classic Restorations, 2006.09.11. Mac OS 8 and 8.1 add some useful new features and tools, and it can even be practical on 68030-based Macs.
- Vintage Macs with System 6 run circles around 3 GHz Windows 2000 PC, Tyler Sable, Classic Restorations, 2006.07.06. Which grows faster, hardware speed or software bloat? These benchmarks show vintage Macs let you be productive much more quickly than modern Windows PCs.
- Floppy drive observations: A compleat guide to Mac floppy drives and disk formats, Scott Baret, Online Tech Journal, 2006.06.29. A history of the Mac floppy from the 400K drive in the Mac 128K through the manual-inject 1.4M SuperDrives used in the late 1990s.
- System 7.6.1 is perfect for many older Macs, John Martorana, That Old Mac Magic, 2006.03.24. Want the best speed from your old Mac? System 7.6.1 can give you that with a fairly small memory footprint – also helpful on older Macs.
- System 7.5 and Mac OS 7.6: The beginning and end of an era, Tyler Sable, Classic Restorations, 2006.02.15. System 7.5 and Mac OS 7.6 introduced many new features and greater modernity while staying within reach of most early Macintosh models.
- Turning an LC or other ancient Mac into a webcam with a QuickCam, Tyler Sable, Classic Restorations, 2006.01.25. As long as it has 4 MB of RAM and a hard drive, any 16 MHz or faster Mac that supports color can be configured as a webcam.
- System 7: Bigger, better, more expandable, and a bit slower than System 6, Tyler Sable, Classic Restorations, 2006.01.04. The early versions of System 7 provide broader capability for modern tasks than System 6 while still being practical for even the lowliest Macs.
- Web browser tips for the classic Mac OS, Nathan Thompson, Embracing Obsolescence, 2006.01.03. Tips on getting the most out of WaMCom, Mozilla, Internet Explorer, iCab, Opera, and WannaBe using the classic Mac OS.
- The Joy of Six: Apple’s fast, svelte, reliable, and still usable System 6, Tyler Sable, Classic Restorations, 2005.12.06. System 6 was small enough to run quickly from an 800K floppy yet powerful enough to support 2 GB partitions, 24-bit video, and the Internet.
- Which system software is best for my vintage Mac?, Tyler Sable, Classic Restorations, 2005.11.22. Which system software works best depends to a great extent on just which Mac you have and how much RAM is installed.
- The legendary DayStar Turbo 040 hot rods 68030 Macs, Tyler Sable, Classic Restorations, 2005.11.29. DayStar’s vintage upgrade can make an SE/30 and most models in the Mac II series faster than the ‘wicked fast’ Mac IIfx.
- Macintosh II Family Technical Overview, darknerd, Angelfire. Some excellent, rarely discussed technical details on the whole Mac II lineup.
- The Mac IIsi, Orion Lawlor
- The Macintosh IIsi, Mel’s Macintosh Universe
- Run Mac OS 8.1 on your ’030 Mac, Charles Moore, Applelinks, 8/8/00. “Born Again enables certain 68030 Macs to support Mac OS 8.1.”
- The IIsi never dies, Adam Robert Guha, Apple Archive, 6/30. “I purchased a Macintosh IIsi at a thrift shop for $25. I thought I might have paid too much….”
- Games for ’030s, Brian Rumsey, Low End Mac Gaming, 5/26. A look at games that run nicely on the old 68030-based Macs.
- Why System 6 for Mac IIs?, Manuel Mejia, Mac Daniel. If they can use System 7, why use System 6?
- System 6 for the Macintosh, Ruud Dingemans. If you have an older, slower, memory-limited Mac, System 6 is fast, stable, and still very usable.
- Faster browsing on older Macs, Online Tech Journal
- Mac Daniel: What about upgrading my IIsi?
- Information on 32-bit addressing
- Memory upgrade guide
- Links to System 6.0.8 and 7.0.1
- Macintosh IIci Technical Specifications, Apple Knowledge Base Archive
- Never connect an Apple II 5.25″ floppy drive to the Mac’s floppy port. Doing so can ruin the floppy controller, meaning you can’t even use the internal drive any longer.
- Internal video on the IIci and IIsi, and the Mac II mono and color video cards, will not work with multisync monitors, whether Apple or PC style. Griffin Technology made the Mac 2 Series Adapter, which works with Apple’s Multiple Scan monitors and most Mac compatible monitors. There was also a version for using VGA-type monitors on older Macs.
- Serial port normally restricted to 57.6 kbps; throughput with a 56k modem may be limited. See 56k modem page. For more information on Mac serial ports, read Macintosh Serial Throughput in our Online Tech Journal.
- The IIsi has an adequate power supply for normal use, but it could be inadequate if you install a different hard drive, a video card, or a PDS card. Although Apple specifies the NuBus slot at 15W, several high resolution or 24-bit cards require more. Worse, the NuBus slot in the IIsi is rated at just 13.3W. The PDS slot is rated at just 7W. The normal hard drive draws 6W; if you replace it with a higher-draw drive, power to the NuBus or PDS slot is reduced accordingly.
- Internal video may reduce system and serial performance; a NuBus video card is recommended.