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New Mac LC II Video Posted on YouTube

I was never really a fan of the LC or the LC II because they were such compromised designs. Apple retired the 68020 with the original Mac II only to re-introduce it with the LC less than a year later. The LC II got a 68030 at the same 16 MHz clock speed as the 68020 in the LC, and the rest of the machine is virtually identical. In order to cut costs, Apple used a 16 bit data bus on both machines, which considerably slowed both machines down, and artificially limited the RAM to 10 MB maximum, no matter if you install larger memory modules.

Both machines had a default resolution of 512x384 in order to get 8 bit color with the 256k of video memory on the logic board. If you install a 68 pin 256k VRAM SIMM, this bumped it up to 640x480 at 8 bit color, which is almost a required upgrade because many Mac applications by this point expected 640x480 at minimum and would refuse to run otherwise, leaving these Macs stuck with older software designed for the compact Macs that ran a screen resolution of 512x342.

The LC III and LC III+ is where things turned around, this was a clean new design that didn't make any serious compromises that drastically affected performance. The bus was a full 32 bits with a faster 25 or 33 MHz 68030 and 512k of onboard VRAM, upgradeable to 768k. I have one of these machines and it's so much nicer. There were upgrades for the LC and LC II that gave them faster CPUs, but the 16 bit bus really limits the performance increase possible.

As for the caps, I would say replace all of them besides the fat line capacitor. I've recapped several LC style machines, including my own LC III in the last couple of years that all were suffering from leaking capacitors. The ones in the power supply are hard to see if they're leaking because it's such a compact design, but once you start pulling caps out of the board, you'll usually see wetness under the caps where the electrolyte is coming out. The same goes for the SMD caps on the logic board, the leaking usually stays mostly under the cap unless the machine is stored sideways, when it will seep out across the board.
 
The original Macintosh LC with a 68020 didn't have a 68841/51, so it couldn't support virtual memory. The LC II with a 68030 did support virtual memory though because the 68030 integrated a 68851 MMU on the die.

Additionally, the LC didn't have the ability to add a 68881/68882 FPU. The LC II had solder pads for a FPU, but no socket, so it also couldn't be upgraded without soldering.

It may be possible to make an LC PDS card with a MMU, but it isn't known if the machine could use it if it was present. There were CPU upgrade cards made for the LC and LC II. I have a MicroMac 25 MHz 68030 upgrade for those machines, which also has a 68881 FPU.
 
Yep, I mentioned the compromised nature of the LC II in the video. It’s not a fantastic machine, but I do indeed like the form factor. It’s also _extremely_ easy to work on, which is quite a positive.

- Alex
 
Owing to the nature of the "pizza box" style case used for several models, you can play musical chairs with logic boards and go all the way up to a 68040 machine. Early Quadra 605s used the exact same case as the LC I - III before the newer stylized design case that looked more like PowerPC machines came out. If you could find an LC III, III+, 475 or Quadra 605 logic board, it'd be a good upgrade.

I recently recapped a Quadra 605 for a customer and modified it to run at 33 MHz since the customer had a full 68040 to replace the stock 25 MHz 68LC040. It was a pretty nice performance boost, and way faster than even my LC III at 33 MHz.
 
GiGaBiTe said:
Owing to the nature of the "pizza box" style case used for several models, you can play musical chairs with logic boards and go all the way up to a 68040 machine. Early Quadra 605s used the exact same case as the LC I - III before the newer stylized design case that looked more like PowerPC machines came out. If you could find an LC III, III+, 475 or Quadra 605 logic board, it'd be a good upgrade.

I recently recapped a Quadra 605 for a customer and modified it to run at 33 MHz since the customer had a full 68040 to replace the stock 25 MHz 68LC040. It was a pretty nice performance boost, and way faster than even my LC III at 33 MHz.
Click to expand...

Yep, I have performed similar modifications. My LC/Performa 578 has a full '040 installed. That machine is one of my favorite 68k Macs, due to the good performance and excellent Trinitron CRT.

- Alex
 
Sorry, I really love my LC. The great thing is, that it can run System6 and so no multifinder and good compatibility.
Afaik the LCII should be able to run System6 as well, but I can't proof it, because I have no LCII.

Here is a short video of my machine: https://youtu.be/YicfqCx5m-k
 
6.0.8 is recommended for the LC/LC II because they're such crippled machines. The limited RAM and 16 bit bus make running System 7 a pig.
 
Is it true that the LC is (sometimes) faster than the LCII ?
68020 vs 68030 at same speed of 16Mhz.
 
The 68030 will be marginally faster because of the on-chip instruction cache and bus burst mode. But much of this is erased in the LC II by being on the same crippled 16 bit bus as the LC.

One major advantage is the 68030 has an integrated MMU, so it can support virtual memory, where the 68020 does not and requires an external 68841/68851. A socket for a MMU isn't provided for on the LC or LC II, neither is one provided for a 68881/68882 FPU, but pads on the logic board exist for it, so it is possible to solder in a socket for one.
 
Thx, I am all in for System6. Virtual memory comes with system7. So no advantage here for my purpose.
It's very interestingly how the amount of moving objects cause very dramatic slowdowns on my LC.
But those games make fun too, even if some scenes are slowed down. (like flashback on 256colors)
 
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