View source for Macintosh Plus

{{Short description|Third model of Apple's Macintosh computer line}}
{{about|the Macintosh computer|the electronic musician|Vektroid}}
{{Use mdy dates|date=October 2013}}
{{Primary sources|date=May 2023}}
{{Infobox information appliance
| name = Macintosh Plus
| aka = M0001A
| image = Apple Macintosh Plus white background (cropped).jpg
| alt = Macintosh Plus monitor, keyboard, and mouse in front of a white background
| caption = Macintosh Plus with keyboard and mouse
| manufacturer = [[Apple Inc.|Apple Computer, Inc.]]
| family = [[Compact Macintosh]]
| releasedate = {{Start date and age|1986|01|16}}
| price = {{USD|2599|1986|round=-1}}
| discontinued = {{End date and age|1990|10|15}} (production)<br />{{End date and age|1996|09|27}} (operating system updates)
| unitssold = 
| unitsshipped = 
| os = [[Classic Mac OS|System 3.0]] – [[System 7|7.5.5]] (except 7.5.2)
| power = 
| cpu = [[Motorola 68000]] @ 7.8 MHz
| memory = 1 [[Megabyte|MB]] RAM, expandable to 4 MB
| RAMtype = 150 ns 30-pin [[SIMM]]
| storage = 
| display = {{convert|9|in|cm|abbr=on}} monochrome, 512 × 342
| graphics = 72 ppi
| sound = 
| input = 
| dimensions = Height: {{convert|13.6|in|cm|abbr=on}}<br>Width: {{convert|9.6|in|cm|abbr=on}}<br>Depth: {{convert|10.9|in|cm|abbr=on}}
| weight = {{convert|16.5|lb|kg|abbr=on}}
| predecessor = [[Macintosh 512K]]
| successor = [[Macintosh SE]]
| related = [[Macintosh 512Ke]]
}}

The '''Macintosh Plus''' computer is the third model in the [[Mac (computer)|Macintosh line]], introduced on January 16, 1986, two years after the [[Macintosh 128K|original Macintosh]] and a little more than a year after the [[Macintosh 512K]], with a price tag of US$2,599.<ref>{{cite web|url=http://www.pcworld.com/article/126692-9/the_25_greatest_pcs_of_all_time.html |title=The 25 Greatest PCs of All Time |magazine=PCWorld |date=2006-08-11 |access-date=2016-05-20|archive-url=https://web.archive.org/web/20080703051524/http://www.pcworld.com/article/126692-9/the_25_greatest_pcs_of_all_time.html|archive-date=2008-07-03|url-status=dead}}</ref> As an evolutionary improvement over the 512K, it shipped with 1&nbsp;MB of RAM standard, expandable to 4&nbsp;MB, and an external [[SCSI]] peripheral bus, among smaller improvements. Originally, the computer's case was the same beige color as the original Macintosh, [[Pantone]] 453;<ref>{{cite web |url=http://www.landsnail.com/apple/local/design/macintosh.html |title=History of computer design: Apple Macintosh |website=Landsnail.com |date=1998-05-17 |access-date=2016-05-20 |archive-date=July 31, 2017 |archive-url=https://web.archive.org/web/20170731162612/http://www.landsnail.com/apple/local/design/macintosh.html |url-status=live }}</ref> however, in 1987, the case color was changed to the long-lived, warm gray "Platinum" color.<ref>{{cite web |url=http://www.landsnail.com/apple/local/design/macplus.html |title=History of computer design: Macintosh Plus |website=Landsnail.com |date=1998-05-17 |access-date=2016-05-20 |archive-date=May 14, 2017 |archive-url=https://web.archive.org/web/20170514081851/http://www.landsnail.com/apple/local/design/macplus.html |url-status=live }}</ref> It is the earliest Macintosh model able to run [[Classic_Mac_OS#System_Software_5|System Software 5]], [[System 6]], and [[System 7]], up to System 7.5.5, but not System 7.5.2.

== Overview ==
[[Bruce Webster]] of ''[[Byte (magazine)|BYTE]]'' reported a rumor in December 1985: "Supposedly, Apple will be releasing a Big Mac by the time this column sees print: said Mac will reportedly come with 1 [[megabyte]] of RAM ... the new 128K-byte ROM ... and a double-sided (800K bytes) disk drive, all in the standard Mac box."<ref name="webster198512">{{cite magazine | url=https://archive.org/stream/byte-magazine-1985-12/1985_12_BYTE_10-13_Computer_Conferencing#page/n363/mode/2up | title=Microcomputer Color Graphics-Observations | magazine=[[Byte (magazine)|BYTE]] | date=December 1985 | access-date=28 October 2013 | last=Webster |first=Bruce | volume=10 |issue=13 | pages=405–418}}</ref> Introduced as the Macintosh Plus, it was the first [[Mac (computer)|Macintosh]] model to include a [[SCSI]] port, which launched the popularity of external SCSI devices for Macs, including hard disks, tape drives, CD-ROM drives, printers, [[Zip drive]]s, and even monitors.<ref>{{cite web|last1=Knight|first1=Daniel|title=ScuzzyGraph and ScuzzyGraph II|url=http://lowendmac.com/2013/scuzzygraph-and-scuzzygraph-ii/|website=Low End Mac|access-date=10 July 2015|date=24 March 2013|archive-date=July 11, 2015|archive-url=https://web.archive.org/web/20150711073521/http://lowendmac.com/2013/scuzzygraph-and-scuzzygraph-ii/|url-status=live}}</ref> The SCSI implementation of the Plus was engineered shortly before the initial SCSI spec was finalized and, as such, is not 100% SCSI-compliant. SCSI ports remained standard equipment for all Macs until the introduction of the [[iMac]] in 1998.

The Macintosh Plus was the last classic Mac to have an [[RJ11]] port on the front of the unit for the [[Apple Keyboard#Macintosh Plus Keyboard (M0110A)|keyboard]], as well as the [[DE-9]] connector for the [[Apple Mouse#Macintosh Mouse (M0100)|mouse]]; models released after the Macintosh&nbsp;Plus would use [[Apple Desktop Bus|ADB]] ports.

The Mac Plus was the first Apple computer to utilize user-upgradable [[SIMM]] memory modules instead of single [[Dual_in-line_package|DIP]] DRAM chips. Four SIMM slots were provided and the computer shipped with four 256 KB SIMMs, for 1 MB total RAM. By replacing them with 1 MB SIMMs, it was possible to have 4 MB of RAM. (Although 30-pin SIMMs could support up to 16 MB total RAM, the Mac Plus motherboard had only 22 address lines connected, for a 4 MB maximum.)

It has what was then a new {{frac|3|1|2}}-inch double-sided [[Macintosh External Disk Drive#800K|800 KB floppy drive]], offering double the capacity of [[floppy disk]]s from previous Macs, along with backward compatibility. The drive is controlled by the same [[Disk controller|IWM]] chip as in previous models, implementing [[Zone Bit Recording|variable speed]] [[Group Coded Recording|GCR]]. The drive was still completely incompatible with [[Personal computer|PC]] drives. The 800&nbsp;KB drive has two read/write heads, enabling it to simultaneously use both sides of the floppy disk and thereby double storage capacity. Like the 400&nbsp;KB drive before it, a companion [[Macintosh External Disk Drive#Macintosh 800K External Drive|Macintosh 800K External Drive]] was an available option. However, with the increased disk storage capacity combined with 2-4x the available RAM, the external drive was less of a necessity than it had been with the 128K and 512K.

The Mac Plus has 128&nbsp;KB of ROM on the motherboard, which is double the amount of ROM in previous Macs; the ROMs included software to support SCSI, the then-new 800&nbsp;KB floppy drive, and the [[Hierarchical File System (Apple)|Hierarchical File System]] (HFS), which uses a true directory structure on disks (as opposed to the earlier MFS, [[Macintosh File System]] in which all files were stored in a single directory, with one level of pseudo-folders overlaid on them). For programmers, the fourth ''[[Inside Macintosh]]'' volume details how to use HFS and the rest of the Mac Plus's new system software. The Plus still did not include provision for an internal hard drive and it would be over nine months before Apple would offer a SCSI [[Hard Disk 20SC|drive replacement]] for the slow Hard Disk 20. It would be well over a year before Apple would offer the first internal hard disk drive in any Macintosh.

A [[compact Macintosh|compact Mac]], the Plus has a {{convert|9|in|cm|adj=on}} 512 × 342 [[pixel]] monochrome display with a resolution of 72&nbsp;[[pixel density|PPI]], identical to that of previous Macintosh models.<ref name=plus-specs>{{cite web
| url = http://support.apple.com/kb/SP190
| title = Macintosh Plus: Technical Specifications
| publisher = Apple
| access-date = March 26, 2021
| archive-date = October 26, 2014
| archive-url = https://web.archive.org/web/20141026161117/https://support.apple.com/kb/SP190
| url-status = live
}}</ref>  Unlike earlier Macs, the Mac Plus's keyboard includes a numeric keypad and directional arrow keys and, as with previous Macs, it has a one-button mouse and no fan, making it extremely quiet in operation. The lack of a cooling fan in the Mac Plus led to frequent problems with overheating and hardware malfunctions.

The applications [[MacPaint]] and [[MacWrite]] were bundled with the Mac Plus. After August 1987, [[HyperCard]] and [[MultiFinder]] were also bundled. Third-party software applications available included [[MacDraw]], [[Microsoft Office Word|Microsoft Word]], [[Microsoft Excel|Excel]], and [[Microsoft PowerPoint|PowerPoint]], as well as [[Aldus PageMaker]]. Microsoft Excel and PowerPoint (originally by [[Forethought, Inc.|Forethought]]) were actually developed and released first for the Macintosh, and similarly Microsoft Word 1 for Macintosh was the first time a GUI version of that software was introduced on any personal computer platform. For a time, the exclusive availability of Excel and PageMaker on the Macintosh were noticeable drivers of sales for the platform.

[[File:Apple-Macintosh.jpg|thumb|250px|The Apple Macintosh Plus at the [[Röhsska Museum|Design Museum]] in [[Gothenburg]], [[Sweden]]]]

The case design is essentially identical to the original [[Macintosh 128K|Macintosh]]. It debuted in beige and was labeled ''Macintosh Plus'' on the front, but ''Macintosh Plus 1&nbsp;Mb'' on the back, to denote the 1&nbsp;MB RAM configuration with which it shipped. In January 1987 it transitioned to Apple's long-lived platinum-gray color with the rest of the Apple product line, and the keyboard's keycaps changed from brown to gray. In January 1988, with reduced RAM prices, Apple began shipping 2- and 4-&nbsp;MB configurations and rebranded it simply as "''Macintosh Plus''." Among other design changes, it included the same trademarked inlaid Apple logo and recessed port icons as the [[Apple IIc]] and [[Apple IIGS|IIGS]] before it, but it essentially retained the original design. On the inside of the case, embossed into it, are the signatures of all the people who worked on designing the Mac Plus, including Steve Jobs, Bill Atkinson, Andy Hertzfeld, Bruce Horn, Jef Raskin and the rest of the historic team.
<ref>{{cite web |last1=Rosen |first1=Adam |title=Signed by Steve Jobs & Co – Signatures Inside the Original Macintosh Case |url=https://www.cultofmac.com/122408/signed-by-steve-jobs-co-signatures-inside-the-original-macintosh-case/ |website=Cult of Mac |access-date=6 October 2022 |archive-date=October 6, 2022 |archive-url=https://web.archive.org/web/20221006154711/https://www.cultofmac.com/122408/signed-by-steve-jobs-co-signatures-inside-the-original-macintosh-case/ |url-status=live }}</ref>
[[File:Macintosh Plus interior 2.jpg|thumb|Inside a Macintosh Plus; the [[cathode-ray tube]] and its associated circuitry on  its right side take up a considerable amount of interior space.]]
{{Anchor|Upgrades}}An upgrade kit was offered for the earlier [[Macintosh 128K]] and [[Macintosh 512K]]/[[Macintosh 512Ke|''enhanced'']], which includes a new motherboard, floppy disk drive and rear case. The owner retained the front case, monitor and analog board. Because of this, there is no "Macintosh Plus" on the front of upgraded units, and the Apple logo is recessed and in the bottom left hand corner of the front case. However, the label on the back of the case reads "Macintosh Plus 1MB". The new extended Plus keyboard could also be purchased. Unfortunately, this upgrade cost almost as much as a new machine.

The Mac Plus itself can be upgraded further with the use of third-party accelerators. When these are clipped or soldered onto the 68000 processor, a 32&nbsp;MHz 68030 processor can be used, and up to 16&nbsp;MB RAM.<ref>{{cite web |url=http://lowendmac.com/1986/mac-plus/ |title=Mac Plus |publisher=Low End Mac |access-date=2016-05-20 |archive-date=March 24, 2018 |archive-url=https://web.archive.org/web/20180324010557/http://lowendmac.com/1986/mac-plus/ |url-status=live }}</ref>

==Long production life==
[[File:Macintosh Plus ED logo.png|thumb|The "ED" at the end of the model name indicates that this Macintosh was sold to the educational market.]]
Although the Macintosh Plus would become overshadowed by two new Macintoshes, the [[Macintosh SE]] and the [[Macintosh II]] in March 1987, it remained in production as a cheaper alternative until the introduction of the [[Macintosh Classic]] on October 15, 1990. This made the Macintosh Plus the longest-produced Macintosh model, having been on sale unchanged for 1,734 days, a record not surpassed until the second-generation [[Mac Pro]] in 2018. It continued to be supported by versions of the [[classic Mac OS]] up to [[System 7 (Macintosh)|version 7.5.5]], released in 1996. Additionally, during its period of general market relevance, it was heavily discounted like the 512K/512K''e'' before it and offered to the educational market badged as the "Macintosh Plus ED".<ref>{{cite web |url=http://appleclub.pl/wp-content/uploads/2017/03/DSCF8798.jpg |title=Picture of "Macintosh Plus ED" front |website=Never trust a computer you can't lift! |access-date=September 6, 2022 |archive-date=September 6, 2022 |archive-url=https://web.archive.org/web/20220906024502/http://appleclub.pl/wp-content/uploads/2017/03/DSCF8798.jpg |url-status=live }}</ref> Due to its popularity, long life and its introduction of many features that would become mainstays of the Macintosh platform for years, the Plus was a common "base model" for many software and hardware products.

== Hardware ==

=== CPU ===
The Macintosh Plus shipped with a Motorola 68000 CPU.

=== Storage ===
The Macintosh Plus did not ship with internal storage, aside from the 128 KB ROM (read-only memory).

=== Media ===
The Macintosh Plus included an 800 KB floppy drive.

=== Display ===
The Macintosh Plus shipped with a 9-inch 512x342 display at 72 PPI (pixels per inch).

=== Audio ===
The Macintosh Plus utilized one 8-bit, 22&nbsp;kHz built-in speaker. No audio-in support.<ref>{{Cite web |last=Page |first=Ian |title=Mactracker - Get info on any Mac |url=https://mactracker.ca |access-date=2025-04-28 |website=mactracker.ca}}</ref>

==Problems==
The lack of fan could cause the life of a Macintosh Plus to end early for some users. As the power supply would heat up, [[solder]] joints inside it would fracture, causing many problems, such as loss of deflection in the monitor or a complete loss of power. As in most early compact Macs, the problem was common in the yoke connector, flyback transformer, and horizontal drive coupling capacitor.<ref>{{cite web |url=http://68kmla.org/files/classicmac2.pdf |title=Classic Mac Repair Notes |website=68kmla.org |access-date=2016-05-20 |archive-url=https://web.archive.org/web/20140606214301/https://68kmla.org/files/classicmac2.pdf |archive-date=June 6, 2014 |url-status=dead }}</ref> A fan was also often added to reduce heat when the machine was upgraded to its full RAM capacity of 4&nbsp;MB.<ref>{{cite web |url=http://lowendmac.com/musings/macplus.shtml |title=Still Useful after All These Years -- The Mac Plus |website=Low End Mac |date=16 September 1998 |first=Daniel |last=Knight |access-date=May 7, 2006 |archive-date=June 27, 2006 |archive-url=https://web.archive.org/web/20060627001650/http://lowendmac.com/musings/macplus.shtml |url-status=live }}</ref>

From the debut of the [[Macintosh 128K]] through the Macintosh Plus, various third-party cooling add-ons were available to help increase airflow through the unit. [[Apple Inc.|Apple]] reorganized the compact Macintosh case to accommodate a fan with the release of the [[Macintosh SE]], which optionally included a heat-generating internal hard disk.

===ROM revisions===
The Plus went through two ROM revisions during its general market relevance. The initial ROM was replaced after the first two months as it had a serious bug which prevented the Mac from booting if an external SCSI device was powered off. The second revision fixed a problem with some SCSI devices that could send the Mac into an endless reset at [[Power-on self-test|POST]].<ref>{{cite web|date=July 1, 1987|title=Technical Note DV14: SCSI Bugs|url=https://developer.apple.com/technotes/dv/dv_14.html|url-status=dead|archive-url=https://web.archive.org/web/20041029061908/https://developer.apple.com/technotes/dv/dv_14.html|archive-date=2004-10-29|access-date=2016-05-20|website=developer.apple.com}}</ref>

==Emulators==

*[[Multi Emulator Super System|MESS]]
*[[Mini vMac]] — can [[emulator|emulate]] a Mac Plus on a variety of platforms
*[[Spectre GCR]]

== Timeline ==
{{Timeline of compact Macintosh models}}

==References==
{{Reflist}}

==External links==
{{commons category|Macintosh Plus}}
*[https://support.apple.com/kb/SP190 Macintosh Plus technical specifications] at apple.com
*[https://archive.org/stream/byte-magazine-1986-06/1986_06_BYTE_11-06_Computers_and_Music#page/n91/mode/2up BYTE takes an early look at the Mac Plus]

{{Apple hardware before 1998}}

[[Category:Compact Macintosh|Plus]]
[[Category:68k Macintosh computers|Plus]]
[[Category:Computer-related introductions in 1986]]
[[Category:Products and services discontinued in 1990]]
[[Category:Products and services discontinued in 1996]]