Mac LC II, a Compromised Mac

Second Class Macs are Apple’s somewhat compromised hardware designs. For the most part, they’re not really bad – simply designs that didn’t meet their full potential. The LC II (a.k.a. Performa 400-430) was a slightly less crippled version of the LC.

Macintosh LCInstead of running a 32-bit 68020 CPU on a 16-bit bus, it uses the 32-bit 68030 CPU on the same 16-bit bus. This Using a slightly modified LC motherboard instead of a new design kept costs down – and the letters LC meant Low Cost.

The biggest improvement was boosting base RAM from 2 MB to 4 MB. The downside to this is that the only way to reach the 10 MB limit is by adding two 4 MB SIMMs. Yes, that’s right – you had to have 12 MB installed so you can use 10 MB!

Still running a 32-bit CPU on a 16-bit data bus and limited by design to support no more than 10 MB of RAM, the 68030 does offer virtual memory. The LC II benchmarks at about 60% the performance of the Mac IIx, even though both use the same 16 MHz 68030 CPU. Again, this is due primarily to the 16-bit memory bus.

As a cost-cutting measure, Apple eliminated the internal connector for a second floppy drive that had been present in the original LC (fewer than 5% of LCs were sold with two floppies). The video circuitry was tweaked to better serve those using VGA and multisync monitors.

Although no faster than the LC, the LC II is what the LC could have been if Apple had avoided the old 68020 CPU. (Most benchmarks show the LC II is slightly slower than the LC!)

Still, it wasn’t a horrible Mac, just a compromised one.

Details

  • Introduced March 1992 at $1,400; discontinued March 1993 (released as Performa 400, 405, 410, and 430 in September 1993; model number reflects software bundle, not any difference in hardware)
  • requires System 6.0.7 to 7.5.5
  • CPU: 16 MHz 68030
  • FPU: 68882 (optional, uses PDS slot)
  • Performance: 1.7 (relative to SE, compare to 1.8 for LC, 2.9 for Mac IIx)
  • RAM: 4 MB on motherboard, expandable to 10 MB using a pair of 100ns 30-pin SIMMs; can use 1 MB, 2 MB, and 4 MB SIMMs (cannot address more than 10 MB, even with 12 MB installed)
  • video: 256 KB VRAM, expandable to 512 KB; supports 512 x 382 and 640 x 480 resolutions (must have 512 KB VRAM for 8-bits at 640 x 480)
  • L2 cache: none
  • ADB: 2 ports for keyboard and mouse
  • serial: 2 DIN-8 RS-422 ports on back of computer
  • SCSI: DB-25 connector on back of computer
  • LC PDS slot

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