Macintosh Plus Upgrades

I’ve been lucky enough to pick up a few upgrades to my classic Macintosh systems over the years, and in the process of hunting down information on those upgrades I’ve come across ads and reviews of a lot of different options that have been produced over the years for a Macintosh Plus, so I thought I’d create this entry to capture some of what I’ve found, and hopefully people will comment on ones I’ve missed.

Photo of the new MacPlus, MacWorld April 1986

1. Baseline Macintosh Plus

I currently have 3, 1MB Macintosh Plus Systems, all upgraded to 4MB, and two upgraded with 4MB Novy Quik 30 (030/25MHz) boards.

  • Dates: 1986/01/16 to 1990/10/15, MacWorld April 1986: A change for the plus, article reviewing the new MacPlus in comparison to the 128k and 512k
  • Processor: Motorola 68000 running at 8MHz
  • Data Path: 16, 8
  • Memory: 1MB to 4MB, four 30-pin SIMM slots, 256K or 1MB SIMMs, min speed 150ns, must be installed in groups of two: 512K (2 x 256K), 1MB (4 x 256K), 2.5MB, 4MB. This system cannot use two-chip 1MB SIMMs.
  • ROM: 24-bit addressing mode, ID $0075, version $6000, size 128k
  • Screen: 512×342 1-bit black and white
  • Keyboard: RJ45 connector, the Macintosh Plus was the last Macintosh to use this connector for it’s keyboard before the move to the Apple Desktop Bus (ADB)
  • Mouse Port: DB-9 pin, the Macintosh Plus was the last Macintosh to use this connector for it’s mouse before the move to the Apple Desktop Bus (ADB)
  • Floppy Size: 3.5″, double sided, standard density, support 400k and 800k disks
  • External Floppy port: DB-19
  • SCSI 1: DB-25, not fully compliant with SCSI standard, main issue is it does not supply terminator power (if you are using a SCSI2SD adapter you will need to supply power via USB)
  • Supported OS: see my entry on Selecting your System Software for your 68k Macintosh

2. CPU / FPU upgrades (may include memory)

Immediately after it’s release in 1986, 3rd party upgrades started getting created for the plus, starting with math co-processors, and maxing out with the release of the Total Systems Gemini Ultra a 68030 processor running at 50MHz. From what I can find there is no 68040 accelerator for the Macintosh Plus, and none that run faster than 50MHz.

I wanted to track down information on my Novy Quik 30 boards, and decided to create this list as I went through back issues of MacUser, MacWorld and upgrade books on the Internet Archive. I’m not sure if someone has done this before, but I couldn’t find a definitive list. I’m also adding links to drivers/enablers, manuals and photos as I find them.

NameCPUFPUMemoryComments / Review
Brainstorm Accelerator Plus16 MHz 68000Photos: Chips, Manuals
Details: 1991 Press Release, MacWeek upgrading and repairing your Mac page 211, Upgrading and Fixing MACs for dummites page 72, Low End Mac, MacUser April 1993 page 121
Two chip motherboard modification, 16MHz 68000 and a ASIC chip to replace the Apple timing chip. The ASIC acts as a bus accelerator and doubles the bus speed to 16MHz, requires memory to be updated to 100 ns or faster. $250 USD launch price in 1991. Requires a system extension
Computer System Associates FasTrack8MHz 68020Details: MacWorld February 1990 page 128
Dove Marathon Racer 030 Plus16 MHz 68030OptDetails: MacWorld August 1990 page 142, MacWorld July 1991 page 217, MacUser April 1993 page 121
Clip on, Optional Extended Video
Levco Prodigy 416 MHz 68020Opt4MBDetails: Macworld August 1986 page 90, MacWorld February 1988 page 141, MacWorld August 1988 page 100
No MMU, Optional 68881 FPU, SCSI port can be used internally to attach to Levco’s OverDriver internal hard disk or to an external SCSI hard disk through a 25-pin connector that mounts in the Mac’s battery compartment, connector for MegaScreen Plus from Micrographics Images, RAM disk. Includes fan and power supply.
General Computer Company Hyperdrive 200012 MHz 68000Opt1.4MBDetails: MacWorld March page 63 , Macworld August 1986 page 90, MacWorld April 1987 page 40
No MMU, Optional 68881 FPU, adds internal 20MB hard drive
MacMemory TurboMax16 MHz 68000Opt4MBDetails: MacWorld February 1988 page 141, MacUser March 1988 page 124 (has photo)
No MMU, Connector for the Big Picture monitor from E-machines, SCSI port, RAM disk. Includes fan and power supply (review)
MacProducts RailGun 020 Plus16, 25 MHz 68020Details: MacWorld February 1990 page 128
MacProducts USA Railgun 030 Plus16, 25, 33 MHz 68030OptDetails: MacWorld February 1990 page 128 (16, 25), MacWorld August 1990 page 142 (16, 25, 33), MacWorld July 1991 page 217, MacWorld June 1992 page 150, , MacUser April 1993 page 121
Clip on
MacProducts USA Magic 02012.5 MHz 68020IncnoneDetails: MacWorld February 1988 page 141, MacWorld August 1988 page 100
No MMU, Cpu can be upgraded to a 68030
MicroMac MultiSpeed25 MHz 68030OptDetails: MacUser April 1993 page 121
Clip on, Optional Extended Video
Newbridge Microsystem Ultramax NM 03025, 33 MHz 68030Details: MacWorld February 1990 page 128 (MX-25 and MXC-33)
Newlife Computer Corporation, NewLife 2525Mhz 68030Details: MacWorld July 1991 page 217, MacWorld June 1992 page 150, , Macintosh Do It Yourself Upgrade Book 1992 page 129, , Build your own Macintosh and save a bundle 1992 page 100 (photo)
Network Specialties Jump 02012 MHz 68020Opt4MBDetails: MacWorld February 1988 page 141, MacWorld August 1988 page 100
No MMU, StretchScreen and StretchProjector, Can also run at 16 and 24 MHz
Novy Systems ImagePro16, 25, 33 MHz 68030YesDetails: MacUser April 1993 page 121, Macintosh Do It Yourself Upgrade Book 1992 page 131
Clip on, Extended Video
Novy Systems Mac208MHz 68020OptNoDetails: MacUser March 1988 page 122 (has photo)
Novy Systems Mac20Mx 12, 16, 20 and 24 MHz 68020Opt4MBDetails: MacWorld February 1988 page 141, MacUser March 1988 page 122 (has photo), MacWorld February 1990 page 128
No MMU, Includes fan and power supply, SCSI port is optional
Novy Systems Quik3016, 25, 33 MHz 68030Details: MacWorld August 1990 page 142, MacWorld July 1991 page 217, MacWorld June 1992 page 150, Macintosh Do It Yourself Upgrade Book 1992 page 129 (photo), Build your own Macintosh and save a bundle 1992 page 100 (photo)
Radius Accelerator 1616 MHz 68020Opt32K cacheDetails: MacWorld February 1988 page 141, MacUser March 1988 page 124 (has photo), MacWorld August 1988 page 100, MacWorld February 1990 page 128, MacWorld August 1990 page 142
No MMU, Full Page Display (SE only)
Ryad Mac Engine GT16 MHz 68000No4MBDetails: MacWorld February 1988 page 141, MacWorld August 1988 page 100
No MMU, Includes fan and power supply, and SCSI port
Ryad MacEngine Turbo16 MHz 68020Opt4MBDetails: MacWorld February 1988 page 141, MacWorld August 1988 page 100
No MMU, Includes fan and power supply, and SCSI port
Spectra Micro Development MacAccelerator12 MHz 68020IncNoneDetails: MacWorld February 1988 page 141, MacWorld August 1988 page 100
No MMU, Connector for the Big Picture monitor from E-machines
Spectra Micro Development ProBoard16MHz 68020Details: MacWorld February 1990 page 129
Total Systems Integration TSI-02012, 16 MHz 68020Opt4MBDetails: MacWorld February 1988 page 141, MacWorld August 1988 page 100
No MMU, Includes fan and power supply, and SCSI port
Total Systems Gemini 02016, 25 MHz 68020Details: MacWorld February 1990 page 129, MacWorld August 1990 page 142
Total Systems Gemini 03016, 20, 25 MHz 68030Details: MacWorld February 1990 page 129, MacWorld August 1990 page 142
Total Systems Gemini II20, 25, 33, 40 MHz 68030Details: MacWorld July 1991 page 217
Total Systems Gemini Ultra20, 33, 50 MHz 68030Details , MacWorld June 1992 page 150, Macintosh Do It Yourself Upgrade Book 1992 page 131, , Build your own Macintosh and save a bundle 1992 page 98
Total Systems Mecury16 MHz, 68030Details: MacWorld August 1990 page 142, MacWorld June 1992 page 150, , Macintosh Do It Yourself Upgrade Book 1992 page 131
Quesse MacceleratorN/AYesDetails: Macworld August 1986 page 90
Adds a National 32081 floating-point co-processor. The board clips on to the Mac’s 68000 cpu. Requires QuickSANE to be run first so that SANE routies are routed to the co-processor.

3. Memory Upgrades

The Macintosh Plus can be expanded on the motherboard with up to 4MB of memory, there is no way to increase memory available to applications beyond that 4MB limit, but you can make use of addition memory as a Ram Disk.

There were some memory addons created to allow the Macintosh Plus to make use of less expensive chips

List of Memory Upgrade Boards: MacWorld 1988 page 144,

4. Video Upgrades

Soon

5. Networking Upgrades

Soon.

6. Early Storage Addons

MacWorld April 1986

I’m not going to capture any of the large, large number of SCSI storage devices that can be used with the Plus, and pretty much any other system that supports SCSI. Instead I’ll only includes storage devices that are truly unique to the Macintosh Plus.

One thing I will mention about the Mac Plus SCSI connector, you may occasionally run in to issues where a device will not work as expected. For example you need to use special settings for a SCSI2SD card to work, and the MacPlus doesn’t provide terminator power, so devices that draw power from the SCSI bus can’t be directly connected to the Plus, e.g. the Asante DeskTop EN/SC SCSI to Ethernet adapter. Also the MacPlus’s SCSI is fairly slow, the original drives used a 3:1 interleave,

Also unlike most systems with SCSI devices, the Plus has a unique boot-up sequence: floppy; SCSI ID 6, 5, 4, 3, 2, 1, 0., vs. floppy then 0, 1, …

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