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LC575, Apple IIe card and CommSlot ethernet = can coexist?


Well-known member
Hi all,

I recently restored a grotty LC575 and am setting about giving it a new purpose.  Eyeing off my Apple IIe card which hasn't had a home - and a spare CommSlot Ethernet card.

Scant reports online suggest the CommSlot card will disable the Apple IIe card owing to addressing issues (CommSlot needs 32-bit, Apple IIe needs 24-bit - which can be switched on and off using < Mac OS 7.5.5).

To save me hours - can anyone confirm if both cards can coexist in an LC575?





Well-known member
I'm interested to know this as well - I was about to mod my case to allow the comslot1 to fit in a CC case beside my IIe card (HDD power harness internally is just a few mm too far down). Would rather avoid breaking plastic if ethernet commslot wont work with the IIe card.



Very interesting, since nobody has answered yet, I've got a question/notion or two for testing. Are you saying that 7.5.5 switches addressing modes on the fly? You might get away with it if there's a method of swapping extension sets on the fly as well? Maybe someone knows of a solution for that? Seems doubtful to me, but a reboot using System Picker might work well enough? I not, a pair of boot partitions should work well enough I'd think, that would disable one card or the other on reboot using that control panel. KISS principal would have me opting for the latter, especially if I had SCSI2SD or the like available. You'd need but set up two different cards for the experimentation phase rather than bodging it on a single card.

@erichelgeson probably no need to remove plastics if this works out. I'd imagine it should be easy enough to flop the NIC over and across the IIe card using a PCI extension cable. Place the NIC atop the logic board components horizontally at some point? You need to remove a few edge card teeth to mod it to proper length for fitment. No biggie if you're hooking up WiFi, it would make that hack simple. No biggie if not, just install a panel mount RJ-45 to the NIC's backplate and set up a jumper the connection back across the IIe card?



Well-known member
Looks like I'll be trying this out - was feeling lazy hence the initial query.

Both cards, System 7.5.5, tests to come.



Daring Pioneer of the Future
Staff member
Are you saying that 7.5.5 switches addressing modes on the fly? You might get away with it if there's a method of swapping extension sets on the fly as well?

No. Under Conventional Wisdom on this topic, you would use the Memory control panel to switch between 24 and 32-bit addressing, just as on all other machines and OS versions where this is a thing. Then, you would need to reboot for your change to take effect.

The same would apply for extension sets.

That said: I have seen a couple people report getting these running on 580/630 which would imply that the Apple IIe card actually does work under 32-bit addressing and presumably that it could work alongside a CommSlot 1 device, which would, well, make the run on 575 boards that much more severe, but, maybe more practically, if 630s can do it, then it opens up the utility of the IIe card and opens up options for building bridging systems that have more overall functionality.

Granted, like, I know that this is not a popular take but there's always localtalk and (perhaps more popular) SCSI ethernet. Though, I know how much more convenient it'd be if this one most widely available LCPDS add-on worked alongside the most desirable thing to put in a comm slot, and, I agree, and, "me too", etc etc.



Well-known member
Based on your comments I did a bit more googling and found a thread here from 2017 -

Appears to come to the conclusion this will not work. But if someone did get it working in a 580/630 that would be great to hear how.



Well-known member
If this doesn’t work, and there are users who want to run an Apple IIe card with a 68040, it does work just fine in a LC475/Q605, and in fact even if the board has been overclocked to run at 33mhz. To utilize Ethernet, one could use one of the SCSI Ethernet adapters at the same time. 



Well-known member
Thanks Mr Fahrenheit,

Yep the LC475 is the only other Mac I have that'll take the Apple IIe card, it's next in line if the 575 doesn't like :)   I unusually like the LC575 more than other LCs.


Brett B.

Well-known member
I will be curious to see what happens... I have mine in a LC550 with OS 7.5.5 and way more than 8MB RAM and it works fine although as noted I do have to turn 32 bit addressing off when using the card.  It will request that I do so before the software will run IIRC.  That's a totally different animal than your 575 though.

I always kinda thought LC and LCII were the perfect homes for these cards, especially with minimal RAM and very small hard drives commonly found in them, and system 6.0.8L.