Macintosh Plus
Macintosh Plus



Setname:  macplus   
Year: 1986
Manufacturer: Apple Computer
Status: good  works
Type: Buisness Computer / Terminal
Clones: Macintosh 512ke,
Mac 512
Emulation info
Overall emulation:  good   
Color emulation:  good  
Sound emulation:  good  
Graphics emulation:  good  
Savestates:  unsupported   

Tech info
 Base hardware: (available in all slot configurations)
M68000 ("maincpu")cpu 7833600 Hz
I8021 ("mackbd:mackbd")cpu 3000000 Hz
Speaker ("mono")audio
Mac Audio Custom ("custom")audio
Screen ("screen")raster horizontal 512 x 342 @ 60.150000
Media devices
floppydisk ("floppy0") floppydisk1 flop1 dsk, img, image, dc, dc42, fdi, td0, imd, cqm, d77, d88, 1dd
floppydisk ("floppy1") floppydisk2 flop2 dsk, img, image, dc, dc42, fdi, td0, imd, cqm, d77, d88, 1dd
BIOS options
v3 Loud Harmonicas
v2 Lonely Heifers
v1 Lonely Hearts
romdisk self-boot (1/1/2015)
RAM options
1M 1048576
2M 2097152
2.5M 2621440
4M 4194304
4M 4194304
Software lists

 Optional hardware: (available with specific slot configurations)

 Configure the slot options for macplus:
 Slot Value

Show detailed info about 'Configurations' of this system


Show detailed info about 'Slot Options' of this system
Slot options

NameValueCompatible device(s)
scsi:1 harddisk scsihd
scsi:2 harddisk scsihd

Romset info
ROM NameSizeCRC32SHA1Dump StateBIOS option
modplus-harp2.bin163840 ba56078ddebdf328ac73e1662d274a044d8750224f47edefgoodromdisk
4d1eeee1 - macplus v1.rom131072 4fa5b399e0da7165b92dee90d8b1522429c033729fa73fd2goodv1
23512-1007__342-0342-a.rom-lo.u7d65536 5aaa4a2f5dfbfbe279ddadfae691c95f552fd9db41e3ed90goodv2
23512-1010__342-0341-b.rom-hi.u6d65536 65341487bf43fa4f5a3dcbbac20f1fe1deedee0895454379goodv2
macplus.rom131072 b2102e8e7d2f808a045aa3a1b242764f0e2c7d13e288bf1fgoodv3


* CPU: Motorola MC 68000 7.8336 MHz
* RAM: 1 MB (up to 4 MB) IBM RAM SIMM's as well as any other 1MB SIMM could be added
* ROM: 128 KB
* Graphic Modes: 512 x 342 dots
* Colors: Monochrome
* Sound: Tone Generator & Digital-Analog converter (22kHz sampling rate)
* I/O Ports: RS 232/422 x 2 for printer and modem, SCSI, external F.D. unit, ext. loudspeaker
* Keyboard: Full-stroke 78 keys with numeric keypad
* Built In Media: One 3.5" 800 KB disk-drive
* OS: Macintosh System (from 3.2 to 7.5)
* Built In Language: None


MESS supports the emulation of macplus with two hard disks and two floppy drives connected. The former ones use "harddisk1" (hard1) and "harddisk2" (hard2) for .chd and .hd files; the latter ones use "floppydisk1" (flop1) and "floppydisk2" (flop2) for disk images in .dsk, .img and .image.dc format.


This system requires full keyboard emulation to work correctly. At startup, full keyboard emulation mode is enabled by default. Whilst in full keyboard emulation mode, some key associated functionality may be disabled (like the ESC key for EXIT). The keyboard emulation mode is toggled using the "Scroll Lock" key (by default).

RAM options

Different RAM configurations are possible for the macplus in MESS. You can switch between them, changing the -ramsize parameter. At command line, you simply have to add ''-ramsize ram_value'', where //ram_value// can assume one of the following values

1m (default)

History and Trivia

Introduced on 16th January 1986, the Macintosh Plus was the first real improvement of the original Macintosh 128k (The Macintosh 512k was just a Mac 128k with 512 kb of RAM). It had several new features.

The extended ROM held the new version of operating system: it supported hard disk units, the SCSI bus, and the new file system: HFS (Hierarchical File System), along with many other new features (Time Manager etc.). Additionally, various routines and managers previously located in RAM (Appletalk manager, RAM Serial Driver, Standard File Package etc.) had been moved to ROM.

The new floppy disk unit could use double-sided 800 kb disks (compared to single-sided 400 kb for the Macintosh 128k). It came with 1 Mb of RAM, and could easily be expanded to 4 Mb, using standard 1Mb SIMMs. It had an enhanced keyboard with a numeric pad and last but not least, it had a SCSI 1 interface which allowed to connect several high speed peripherals (maximal transfer rate of 312 kbyte/s on Mac Plus - which is incredibly inefficient) such as hard disks and scanners.

Although the Mac Plus was made obsolete in march 1987 by the new Macintosh series (Macintosh SE and the Macintosh II), it remained in production as a cheaper alternative until the introduction of Macintosh Classic on 15th october 1990. This makes Macintosh Plus the longest lived Macintosh ever produced.

(info from


* Applefritter (Excellent site about all Apple models,clones,prototypes,etc...) --
* Everything for the Mac --
* Homepage of Gamba --
* Mac Plus at --

Other Emulators

* Basilisk II --
* vMac --

Edit the History info for this game.


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