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LC III has errors installing 7.1 or 7.5.3

zezba9000

Well-known member
I have an LC III that I cannot get to install a OS. Using a up to date FloppyEmu.
Tried multiple copies of 7.1, 7.1.1, 7.1.2 & 7.5.3 (that were in .dsk or .img format). The installers just keep erroring out. Different versions will error out on different disks.

Can someone share a working copy of 7.5.3? Ideally something they know works on LC III.

I also re-capped & cleaned the board just in case that was an issue (but nothing changed).

The computer is perfectly stable doing everything so I think it may be the OS copies I have are bad or incompatible (I read online lots of ppl have issues with LC III).

If no one has a working copy for LC III, I may manually copy 7.1 OS files to its hardware... then go through upgrade installers.
Or I may need to setup a emulator to make it easier on Windows to extract some zipped .bin files and try some other copies with FloppyEmu.
 

Nixontheknight

Well-known member
Try using a 7.5 installer, then installing fetch and finding an image of 7.5.3 that’s an smi image of all the install disks
 

zezba9000

Well-known member
That requires a CD. LC III needs disks.
I need an approach that doesn't require a working CD drive.
For one there is no way to emulate a CD drive in the future if they went bad (or does someone make a ODE for Mac?).
 

Nixontheknight

Well-known member
That requires a CD. LC III needs disks.
I need an approach that doesn't require a working CD drive.
For one there is no way to emulate a CD drive in the future if they went bad (or does someone make a ODE for Mac?).
The only solution is virtual cd/dvd-Rom utility. That requires an OS to boot from
 

zezba9000

Well-known member
7.5.3 CD version could fit within a 35mb drive image FloppyEmu could emulate.
Maybe if I just copy all the CD files to a drive image, I could install from that.
 

zezba9000

Well-known member
Well it turns out the HD was going bad and its head getting stuck. Trying to take it apart to adjust it, I bent a head (its toast).
So put in a SCSI2SD and just put on OS 7.5.5 directly and everything works!

* Computer re-capped
* Added heatsinks on hot chips
* Add FPU !!
* SCSI2SD drive (still need to get 3D printed part for it)
* Runs fast playing Spectre!

1631424699241.png1631424737068.png1631424782226.png
 

Juror22

Well-known member
Nice job!
Aren't LCIII's the best?

I added an FPU to mine also, it was needed for one of my games.
 

zezba9000

Well-known member
Nice job!
Aren't LCIII's the best?

I added an FPU to mine also, it was needed for one of my games.
Its faster than I expected. Only ever used an LC & LC II in the past for these.
Do you know if the FPU helps in games in general that use "floats"? Or does a game need to be compile specifically to use it?
What game did you use that required it btw?
 

joshc

Well-known member
@zezba9000 Nice LC III, but you can move R14 on the top of the board to R74 on the back. That will boost you from 25MHz to 33MHz, effectively making your LC III into an LC III+

And then buy an LC 475, that is even faster still because the 68040 was a huge leap from the 68030. :D
 

zezba9000

Well-known member
But the LC 475 / Performa 475 don't have a integrated FPU right? (as you can't add one).

Also why did Apple limit the clock to 25mhz when it ran fine at 33mhz?
I'll have to consider if I want to do this or not. Looks like an easy change but sometimes I prefer devices more true to their original release design.
 

joshc

Well-known member
But the LC 475 / Performa 475 don't have a integrated FPU right? (as you can't add one).

Also why did Apple limit the clock to 25mhz when it ran fine at 33mhz?
I'll have to consider if I want to do this or not. Looks like an easy change but sometimes I prefer devices more true to their original release design.
The 475 can run with a full 040 which includes the integrated FPU, you just swap the low-cost 040 processor out for a full one - it's a socketed CPU. You can also get a 475 running at 33MHz with a similar resistor mod.

Apple was funny about configs back then and wouldn't sell a 33MHz machine if it would hit sales of another model - the LC III+ uses the exact same design, board, everything, all that is different is the placement of that resistor ! Back then, Apple were selling many different configs/variations of these machines, and they would save cost if they could design them in a way that they could share as many components as possible. The LC III/III+ board was used in many different machines, lots of variations of Performa models like the 460, 466 and 467.
 

Juror22

Well-known member
What game did you use that required it btw?
I racked my brain, but do not recall the specific game. If I come across it, I'll repost.
you can move R14 on the top of the board to R74 on the back. That will boost you from 25MHz to 33MHz, effectively making your LC III into an LC III+
I didn't know this, I may try this mod - its easy enough to reverse, if I need to go back for some reason.

buy an LC 475, that is even faster still
Always looking for a 475/Q605 MB that needs a new home. (at reasonable price of course and there is the catch), and as zezba9000 pointed out, it would need the full 040 treatment, since I'd want the FPU, (personally).
 

zezba9000

Well-known member
I didn't know this, I may try this mod - its easy enough to reverse, if I need to go back for some reason.
Looking it up, the only thing LC III+ doesn't support is some L2 cache card maybe (that LC III does). And the mod effects this the same way.
So unless you use that card doesn't sound like their is any issue. (I'm still considering if I want to do the mod or not)
 
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