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I've been swindled! Also, ethernet on LCII/III question.

luckybob

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Yesterday for $5 I found a mac LCII at thrift store and I snatched it up. The outside case is so old and yellow it looks like someone had it sitting outside since 1994... Anyway, I got it because I fully intended to strip it for parts. Super drive floppies are a PITA, and it had a small 80mb scsi hard drive. the nice thing about this particular hard drive is its power requirements. If the sticker can be believed, it only wants 200mA from each the 5v and 12v lines. Which is excelent, because I want to mod a hard drive INSIDE a mac plus. It had 2x 4mb simms that were salvaged and put into a SB 3600 sound card and the coolest part is, it had an Ethernet card! YAY! The LCIII I have needs one of these! The power supply would be a nice backup as well.

So, question #1; the network card from the LCII fits into my LCIII, but will it work?
question 2: Do i leave the co-processor in the motherboard, or do I put it in the slot on the network card? (I'm not joking, I remember something about this, but I'm not sure)

While poking around in these machines I realized something. The processor in the LCIII is marked the same as the LCII. This isnt right! they were supposed to be a different! I know the 3's were supposed to run at 25mhz and some at 33! But the processors are both the same between the LCII and LCIII! Here are some pictures; The LCII is on the LEFT and the III on the right.



Did my father get swindled back in 1994 or do they really overclock the processors for the 3's?
 
The LC PDS Ethernet Card works in all the machines with an LC PDS Slot, Color Classic, LC, LCII, LC3, all the 575 series, the 630 series.

I really see no benefit for the Coprocessor unless your doing lots of math type stuff. my LCII and II also have the same processor..
 
The LC PDS Ethernet Card works in all the machines with an LC PDS Slot, Color Classic, LC, LCII, LC3, all the 575 series, the 630 series.

I really see no benefit for the Coprocessor unless your doing lots of math type stuff. my LCII and II also have the same processor..

its good to hear. But do I put the co-pro in the Ethernet card or do I leave it where it is? I'm not going to remove it and let it sit. My father got it because he did a lot of CAD and graphics work on this machine. While I'm probably going to game on it, I fail to see a reason to remove it.

But my main concern now is the processor speed. is the 3 running at 16 or 25? And diddnt they do a bus change between the 2 and 3? wasn't the 2 limited to like 10mb of ram and the 3 to 36mb? I can't imagine apple knowingly running a chip marked for 16, at 25/33.
 
If its pin compatible go ahead, the LCII is limited to 10mb via 30pin SIMMS, the LC 3 is a max of 36MB, I have a 32MB stick in mine. Works rather well. my LC 3 is just doing MacIP Serving duties
 
While poking around in these machines I realized something. The processor in the LCIII is marked the same as the LCII. This isnt right! they were supposed to be a different! I know the 3's were supposed to run at 25mhz and some at 33! But the processors are both the same between the LCII and LCIII! Here are some pictures; The LCII is on the LEFT and the III on the right.

Quite often they will use one CPU for all similar models and then run them at different clock speeds based on the hardware around it as it as cheaper for them to order a couple hundred thousand 33 mhz chips than to order equal quantities of two different speeds. Also on CPU fab lines quite often slower speed chips are simply rejects from the faster speed line (Intel did that with celery's for ages).

On the other side you have Motorola, who would run tests against their slower clock line for the 'gems' that could handle higher clock speeds. While Intel intentionally makes for example, 1ghz P3's and then sold the ones not up to snuff as celery 600's, Motorola intentionally makes 16mhz and sells the gems as 25mhz -- which is where the rest of the numbers on the chip come into play. Somewhere in there is likely a 'quality rating'. Putting an an above spec chip in at 25mhz was quite common practice... consider it the same as the difference between a AMD or Seimens 8088, 8088-1 and 8088-2; the -1 was rated to 10mhz, the -2 could handle 8mhz, the numberless was only rated to 5mhz, and 99% of them were all made of the same circuit design on the same production line from the same silicon... what number got stamped on them usually being related more to testing results, imperfections in the base wafer and product demand than by design.

Though much like the rest of their goofy hardware practices, Apple is notorious for often giving you NOT what the label says -- sometimes it's more, sometimes it's less...

A great example of this were the toilet seat G3 MacBooks -- which regardless of the clock speed they were sold at -- be it 266, 333 or 450... mostly seem to have 500mhz rated G3's in them; the limiting factor was often the RAM they soldered to the mainboard as early on they had trouble getting 100mhz parts, so you typically found 66mhz RAM in them. In fact, the only discernible difference between many 266 and 333 models were the orientation of the clock multiplier resistors on the mainboard and the inclusion of actually soldering in the second USB port. Late model 266's and 333's often came with PC-100 or even PC133 on the mainboard; meaning if you were willing to play with the surface mount resistors, you could push them up to 450-600 depending on the rest of the mainboard parts... and if you were willing to rip out the dialup adapter to put an actual *SHOCK* heatsink on the CPU...

Since again, Apple wouldn't know proper cooling if it stripped naked, painted itself purple and hopped up on a desk to sing "Oh look at what a big cooling fan I am!"... Given their propensity for skipping heat sinks all-together in the G3 era and instead wrapping the CPU's in insulating foam so the outside of the laptop didn't get warm... Which may be another reason they would take CPU's rated higher than the design and then underclock/undervolt them. (and even then many early G3 macbooks burned holes clear through the dialup adapter after 5 years or so operation)

You figure in the manufacturing process of chips, how the labelling of chips for speed works, and Apple's "cut every corner then charge premium prices" approach to hardware design -- It's not surprising at all to see a 68030FE16B in a 25mhz machine. Apple's not along in this -- You open up a few of those 25mhz Amiga 3000's you'll find 68030FE16B's in there too.

... and hey, at least you've got a 25mhz 68882 mathco next to it :D
 
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I know things like this happened with Intel chips during the same general time frame. People would take lower rating chips and scrape off the markings and re-mark them as faster chips.

I guess apple assumes their customer base wouldn't bother to even look. Or even know what they are looking at if they did. :p

One question remains, do i leave the co-pro on the motherboard or do I put it on the Ethernet card?
 
Why on earth would a general purpose GPU go on the Ethernet card?!? If it has a empty socket, I'm pretty sure it's NOT a 68882 that goes there.
 
Yeah its a 68882 that goes in that socket, alot of ethernet cards for macs in those days had the option of a coprocessor.. My SE/30 has a 68882 installed on the ethernet card as well, same with the card in my LC and LCII
 
Why on earth would a general purpose GPU go on the Ethernet card?!? If it has a empty socket, I'm pretty sure it's NOT a 68882 that goes there.

Frame checksums and then maybe encryption would be my first guesses. Remember that the first network cards were separate computers in their own rights (IMPS)? Somewhere I have an ISA ethernet card for a PC that had more computing power than the PC it was plugged into. But that system screamed compared to one that had to use the main CPU to do some of the network calculations (think, soft-NIC).
 
It was somewhere to put it. It wasn't for the Ethernet card's use, but for the main system's. Lots of expansion cards for the lower-end Macs had sockets for them. On the IIsi, it was essentially a given. If you got the NuBus expansion card (that turned the PDS slot into two NuBus slots,) you got an FPU. If you got a direct PDS card, odds are it came with an FPU.
 
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