Apple Macintosh IIsi vs Apple Macintosh LC 580

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Macintosh IIsi compared with Macintosh LC 580

	AppleMacintosh IIsi	AppleMacintosh LC 580
Overview
Released
Released	October 1990	1995
Performance
Processor
Processor	68030 20 MHz (Macintosh IIsi)	Motorola 68LC040 33 MHz (Macintosh LC 575)
CPU cores
CPU cores	1	1
Memory
Memory	1 MB	8 MB (better)
Storage
Storage	–	500 MB
CPU
CPU	20 MHz Motorola 68030 with integrated memory management and 0.5 KB L1 cache; 68882 floating-point coprocessor optional through an expansion adapter	Original Motorola 68LC040 at 33 MHz, without an integrated floating-point unit. Apple catalogue gives 66/33 MHz internal/bus clock; optional PowerPC upgrade is excluded from this configuration. Shared Service Source describes it as an updated LC 575
GPU
GPU	Built-in 8-bit colour video supports 512 × 384 and 640 × 480 using 64–320 KB of system RAM	Built-in video uses 1 MB DRAM soldered to the logic board, displaying 32,768 colours at 640 × 480
Memory type
Memory type	1 MB soldered to the logic board plus four 30-pin SIMM slots in one matched bank; 100 ns memory and 1–17 MB total supported by Apple; 512 KB ROM	8 MB standard in the maker catalogue: 4 MB soldered plus one 4 MB SIMM, with a second socket free. Two 72-pin 80 ns SIMM sockets, expandable to 52 MB; the single-bank socket accepts only 1, 4 or 16 MB modules. 1 MB ROM in original service specifications
Storage type
Storage type	Internal 1.44 MB floppy drive with SCSI hard-drive options of 40 or 80 MB; Apple does not document the paired RAM and drive configurations on its support sheet	500 MB internal IDE hard disk in the catalogue configuration, plus manual-inject Apple SuperDrive floppy. Double-speed tray-loading internal CD-ROM is optional or included in some regional configurations; the separately marketed Performa 580CD has its own software and hardware bundle
Expansion slots
Expansion slots	One processor-direct slot can be used directly or with an optional NuBus adapter; no built-in NuBus slot or L2 cache	One 114-pin LC processor-direct slot, one communications slot for optional Ethernet or fax modem, one video-input slot for optional capture hardware and an internal connector for optional external video
Display
Screen
Screen	None built in	14″
Resolution
Resolution	–	640 × 480
Panel
Panel	–	CRT
Refresh rate
Refresh rate	–	66.67 Hz
Display type
Display type	–	Built-in 14-inch diagonal shadow-mask colour CRT, 0.28 mm dot pitch. The exact service manual calls the viewable image 11.5 inches and gives a nominal 240 × 180 mm active raster; these maker descriptions are retained separately
Display features
Display features	–	640 × 480 at 66.67 Hz in the exact timing table (66.7 Hz rounded elsewhere in the same manual); 16-bit colour
Connections
Ports
Ports	Headphone jack	Headphone jack
Front ports
Front ports	–	Stereo headphone socket; front brightness and contrast controls
Back ports
Back ports	One Apple Desktop Bus port, DB-15 video, DB-19 external floppy, DB-25 SCSI, printer and modem serial ports, sound output and microphone input; no built-in Ethernet	One ADB port; one DB-25 SCSI port supporting six external devices; two RS-232/RS-422 serial ports, with 9-pin mini-DIN modem and 8-pin mini-DIN printer connectors; mono sound input and stereo sound output
External displays
External displays	Built-in video supports an Apple colour display at 640 × 480 with 8-bit colour; a compatible expansion graphics card can extend display options	Optional external video connector supports mirroring on compatible 640 × 480 and 800 × 600 monitors, as listed in the shared service manual; no external video socket as standard
Speakers
Speakers	Internal speaker, stereo 8-bit sound output and mono audio input	Two integrated speakers; 8-bit stereo playback and mono recording at 11 or 22 kHz. Optional CD-ROM supports audio-CD playback
Microphones
Microphones	–	Integrated microphone for monaural sound input
Keyboard and mouse
Keyboard and mouse	–	Supports Apple Desktop Bus keyboards and the ADB Mouse II. Maker photograph shows a keyboard and mouse; regional education bundles vary
Design and power
Type
Type	Compact	All-in-one
Weight
Weight	4.5 kg (better)	18.3 kg
Width × depth × height
Width × depth × height	315 × 378 × 102 mm	343 × 419 × 455 mm
Operating system
Operating system	macOS	macOS
Size and weight detail
Size and weight detail	Apple's 4 × 12.4 × 14.9 inch and 10 lb reference dimensions; metric fields are rounded conversions	Apple catalogue: 455 × 343 × 419 mm (height × width × depth), 18.3 kg, varying with installed devices. Service Source rounds the same 17.9 × 13.5 × 16.5 inch case to 455 × 344 × 420 mm and 18.4 kg; headline follows the catalogue’s published metric values
Power supply
Power supply	Maximum 160 W; 100–240 V AC, 50–60 Hz; 3.6 V lithium clock battery and keyboard soft power	Automatically configured 100–240 V AC mains; service supply operating range 90–264 V rms, 50–60 Hz ±3 Hz
Power use
Power use	–	Service Source: 120 W maximum for all line and load conditions. Current support article describes a PowerPC-upgraded configuration and lists 60 W, so that figure is not transferred to the original model
In the box
In the box	Original System Software 6.0.7. Apple lists 15 October 1990 as the introduction date; no separate first-sale day was found	Original 68LC040 model is offered in Apple’s April and October 1995 catalogues; the latter identifies US education-only sales and varying worldwide configurations. Current Apple support article describes an installed PowerPC 601 upgrade card. It records introduction on 3 April 1995, while contemporary Macworld says education shipping was planned for that day; exact actual first retail delivery is unconfirmed, so release retains supported year precision