LC Design and Caveats

The LC ideal

In 1990 Apple launched the Macintosh LC. The LC quite simply stood for 'Low Cost'. It was to be the cheapest Mac in the new line up. It was basically a re-box of the 1987 Macintosh II computer. The 16MHz 68020 CPU and 16-bit 16MHz bus were retained, as was the dual floppy capability (optional). The two different models of LC had either dual floppy or a floppy and a 40MB or 80MB hard disk. These machines were slower than both the SE/30, which was discontinued that year, and that year's Macintosh II machines. It was however also significantly less expensive. It fulfilled its Low Cost role and was often chosen by education authorities for the value it offered, especially the LCIII and upward machines. The range was upgraded progressively and branched into all-in-ones (LC520-LC580) and 'Flat Pack' desktop machines (LC-LC475), which paradoxically came with a 12" CRT screen anyway, until the LC475 was discontinued and replaced with a Power Macintosh equivalent in 1996. There are two Power Macintosh models, the 5200/75 and 5300/100 that were also given the LC moniker but by this time the range had really merged with the Performa range of consumer machines.

The LC and LCII - Bones of Contention?

It is a well appreciated fact that the LC and LCII Macintosh computers were deliberately crippled by Apple to make them lower machines. The LC had a very sluggish 68020 CPU in it that really didn't cope running the newer System 7.0 OS launched shortly after the machine. The LCII had a 16MHz 68030 CPU which, although supposedly much faster, was dragged down by old memory standards, a slow bus and a poor architecture. This meant the first two LCs were, all round, pretty sickly and poor machines. One solution to this problem is that they will both run the older System 6.0.8 operating system. The LC originally came with System 6.0.7 so it is an obvious upgrade for that machine. The LCII however came with System 7.0.1 or 6.0.8L, depending on where you bought it (US or Europe), but will happily run the standard version of System 6.0.8.

RAM is also a roadblock. Both machines will only take up to 10MB of RAM. The machines can both take 2MB 2x4MB 30-pin SIMMs but the LCII loses the ability to address the base 2MB of it's onboard RAM when 8MB of extra RAM is installed.

All in all these machines are not good to use but they are LCs all the same so I have to admire them a tiny bit, they are part of the Flat Pack brotherhood after all.

The LCIII - LCs looking bright at last....

In March 1993 the Macintosh LCII was discontinued and its replacement, the LCIII introduced in February of that year, became the 'low cost' machine in Apple's range for the next 12 months. The LCIII heralded a new age for the LC. Finally Apple had let off with the crippling restrictions the first two models were saddled with and was given a much improved system. Apple introduced a 32bit wide 25MHz bus with a new, improved LCIII PDS slot (which became standard on many later 68k Mac models) and 72-pin 32bit SIMM memory modules rated at a minimum of 80ns. Also the VRAM started at 512k and was expandable to 768k with the addition of a 256k VRAM SIMM. A bigger hard disk complement of 80MB or 160MB also meant breathing space was a little better. The default operating system, System 7.1 (with Enabler 003), was a vast improvement on System 6 and 7.0 and was a good runner on this machine. The RAM slot was designed to accommodate up to 32MB of RAM which, combined with the 4MB of onboard RAM, gave a much improved maximum of 36MB or RAM which has since been upped to 68 or 132MB in some machines using 64MB and 128MB SIMMs respectively (see the RAM section for details). These revisions were carried over to the LC475 and combined with the new more powerful 68LC040 (which had a few FPU issues but that wasn't a problem, for most) and the all-in-one machines. The LCIII revisions finally made the LCs, all in all, pretty practical little machines for everyday use and they became popular systems both in the home, as the Performa 46x series, and in schools.

The Great LCIII/+ Case Mystery - Revised

I have had a great deal of feedback about the whole LCIII case debacle so I decided to re write this section now it *appears* I have cleared this issue up.

The puzzle unraveled as I discovered the Cork built LCIII I have on my desk is not an LCIII but an LCIII+. I have had other reports of LCIII+ and Performa 460 machines (same machine, different badge) having the manual inject disk drive and the newer style hood. The only way, it would seem, to ditinguish the LCIII from the LCIII+ is to remove the hood and read the information on the top of the 68030 CPU. The last number in the main identifier reads 25 on LCIIIs and 33 on LCIII+s, signifying the 25MHz and 33MHz CPU respectively. The original LCIII it seems had the old style hood with the auto inject drive at least up until the LCIII+ was introduced in October 1993, when it may or may not have been changed to the newer style.
It is also worth adding here that the Macintosh Quadra 605, an LC475 in all but looks, was in an altogether different case from the rest of the LCs. It was a level lying case with large oval feet on the bottom similar to those found on the base of other late Quadras, particularely the 800 and 840av.

Auto Inject or Manual Inject - What's it all about?

I have been asked by a few people now to explain the difference between the manual inject and auto inject Apple floppy drives. This paragraph I wrote in a recent e-mail to someone pretty much explains it.

When Apple and Sony designed the original Macintosh floppy drive it was designed so that it would be, like the rest of the Mac, easier to use than an IBM drive. "How on earth do you make a floppy drive easy to use???" I hear you cry... Well the most obvious thing is that they made it eject the disk automatically. The other feature was that the drive, on inserting the disk, snatches it out of you hand and sucks it into the drive so you don't have to push it all the way in. This is the 'auto-inject' design that was used on many early Macs. When Apple made the LC, LCII and LCIII they used auto-inject drives. However, when they introduced the LCIII+ they switched to manual-inject drives which required you to push the disk in all the way till it dropped into the drive. I initially thought this was a bad move from the point of view of Apple's design but, since I have started restoring SE/30s I have discovered why they stopped using the auto-inject drive. The mechanism relies on a series of springs, sliding parts and other metal parts. These get dust and dirt in them after a few years and, as I found out when I attacked a supposedly dead SE/30 super drive with a can of spray alcohol, can cease the drive up totally. The manual inject drive has a much less complex mechanism and so is less likely to fail. I have found however that the eject mechanisms on all Apple floppy drives do go a bit limp after years of use and this can lead to drives, like that in my LCIII+, having problems ejecting the disk if the drive has been used a lot in it's life.