Apple introduced the Macintosh LC III on February 10, 1993 as replacement for the Macintosh LC II. The change from the original Macintosh LC to the LC II was rather pedestrian. The LC II uses a 16 MHz 68030 processor while the LC uses a 16 MHz 68020 processor. The LC II's 68030 is able to use System 7's Virtual Memory, while the LC with its 68020 cannot. However, both of these earlier LCs used the same bottlenecked 16-bit data bus. Enter the LC III. The LC III is substantially superior to the LC II. It has a 32-bit data bus and a fast 25 MHz 68030 processor with an optional 68882 FPU. Its 32-bit data bus allows it to easily handle any version of System 7 while the LC II chokes on anything above Mac OS 7.5. System performance is noticeably faster with the LC III. The LC III originally cost about $1350. I purchased my LC III in 2000 for $100 from a Canadian seller on eBay. The cost of this Mac was such that it got held up in customs at the local international airport and it was a real pain getting it through. My LC III was in new condition and had never been taken out of its box.
|The LC III is designed to support the weight of a monitor and is angled for more comfortable viewing
I picked up a new 15-inch PC monitor to use with it from a department store. 15 inches is the maximum monitor size the LC III can support. The LC III needs an adapter in order to use a PC monitor because the connector will not fit the monitor port and the refresh rate is different. I use a Belkin PC to Mac adapter to convert the signal to Macintosh standard. The adapter has 9 DIP switches. Belkin's manual specifies suggestions concerning how the DIP switches should be set according to the general type of monitor being used. It took a while to get it to work right. If the switches are not set properly, you can end up with a shaky screen. After the DIP switches have been changed, a restart is necessary. I discovered that little trick after spending thirty minutes trying to pick DIP switch settings that would stop the screen from shaking. In desperation, I took my best guess at the DIP switch settings and restarted the computer. To my amazement, it worked.
The LC III originally shipped with either an 80 MB or 160 MB internal SCSI hard drive. My LC III has an 80 MB hard drive. It also has an external Data Place 500 MB SCSI hard drive and a 100 MB Iomega Zip drive. The LC III has a built-in 1.4 MB internal floppy disk drive. The LC III has 4 MB of onboard RAM and is capable of up to 36 MB of RAM using a single 72-pin RAM SIMM. My LC III has 20 MB of RAM installed.
|LC III's Zip drive, 5.25 inch floppy disk drive (connected to Apple IIe Card), and external SCSI hard drive
The LC III has the following ports: one ADB port, one DB-15 video port, one DB-25 SCSI port, one serial printer port, one serial modem port, one speaker jack, and one microphone jack. My LC III also has an Apple IIe Card port for connecting an external 5.25 disk drive and Apple II joystick or paddles using a splitter cable.
Macintosh LC III ports
The LC III originally shipped with Mac OS 7.1. It supports up to Mac OS 7.6.1. I often caution users about installing later versions on System 7 on some older Macs due to the degradation in overall system performance, but the LC III is fully capable if enough RAM is installed to run any version of System 7 with no noticeable performance issues. My LC III uses Mac OS 7.5.5.
"About This Macintosh" showing system software and RAM
Click to view screen capture 1 - (About This Macintosh)
Click to view screen capture 2 - (Monitor Control Panel)
The LC III has 512K of onboard VRAM (video RAM) and one VRAM slot capable of accepting an additional 256K VRAM bringing the total possible VRAM to 768K. My LC III has the 256K 100ns VRAM SIMM installed giving it the ability to display thousands of colors. The LC III supports a variety of resolutions beginning at 512 x 384 and ending at 832 x 624; however, higher resolutions require the full 768K VRAM. See Profile Specs Macintosh LC III page for further details.
The LC III has a single slot for expansion. The LC III uses an extended version of the LC PDS (Processor Direct Slot). Unfortunately, many PDS cards suitable for use in the LC III were designed for the older 16-bit data bus of the previous LCs. Using one of these cards (usually a network or monitor card) could make the LC III run less efficiently and thus negatively affect overall system performance. My LC III has an Apple IIe Card installed in the Processor Direct Slot.
The LC III is extremely easy to open and upgrade
The Apple IIe Card allows the LC III to emulate an Apple IIe. It is a hardware solution to the problem of compatibility with the older Apple II line of computers. This LC III as it is currently configured is one of the most important computers in my collection. It functions as a bridge between the Mac world I live in and the Apple II world of the past. The LC III's internal 80 MB hard drive is partitioned into a 10 MB ProDOS partition and a 70 MB Mac OS 7.5.5 partition. The ProDOS partition is used in conjunction with the Apple IIe Card and acts as the startup drive for the virtual Apple IIe. The Apple IIe Card has a port that accepts an Apple IIe Card splitter cable. This cable is used to connect a 5.25-inch floppy disk drive and a joystick or set of paddles.
Click here to learn more about the Apple IIe Card
The LC III is one of those special Macs that during its time and far beyond had the right combination of performance, configurability, and price. Although it is undeniably a low end Mac, its attributes: 32-bit data bus, speedy 68030 processor, expansive RAM ceiling, expandability, and 768K maximum VRAM for enhanced graphics; made it a bargain in 1993 and today makes it a joy to use with the extensive library of 68K Macintosh software.