Macintosh LC III with FPU and PDS Ethernet card

[DannyMac]

Like many here, I maxed out my childhood Mac. It's an LC III where I purchased all the upgrades that didn't cost an arm and a leg. Cut to a month ago and I finally got around to recapping the mother board and PSU. That went successfully. When testing I added one thing at a time to ensure I could hear a startup chime: I added the RAM, test passed; VRAM, test passed; FPU, test passed, and then I added my Apple LC PDS Ethernet card and nothing, not even a chime or death chime. It messes it up to the point where you need to wait for the PRAM to reset before it goes back to normal (I didn't have a battery installed at the time). I did some research and it seemed one couldn't have the FPU occupied and PDS slot at the same time from some discussion on StackExchange (https://retrocomputing.stackexchange.com/questions/1406/why-do-mac-lc-network-cards-take-an-fpu).

So, I concluded that I would need the Asante LC Ethernet card that has an FPU slot, but I got a BlueSCSI v2 for it and wanted to see how well that works. It works okay, but it is slow (but much faster than a 28.8k modem, at least). It seems like if the connection drops, it results in me needing to force quit apps which throws the whole system out of whack where telling the Mac to restart results in Finder getting stuck, eventually resulting in a hard freeze to where I have to do a Control-Apple-Power On to reboot. It sort of makes me want to avoid getting the Mac online, but I really want to use ircle, FTP, and maybe Hotline.

I got to looking deeper into getting an LC III with FPU an Ethernet card and came across this video:

. They got a Farallon card that doesn't have an FPU socket. They too have an FPU installed on the motherboard. At first, I was thinking, "Poor guy, their Mac won't even POST," but then they got the startup chime and booted. So, what the heck? The person in the YT video says that it was manufactured 5 years after the LC III, so maybe it is designed to co-exist? As far as I can recall, I don't think I have ever tested that Ethernet card. I've not been able to test the Mac with the card without the math co-processor installed since I didn't have a PLCC extractor, but now I think I may extract the FPU and see if the card even works!

Any guidance is greatly appricated!

 

[Nixontheknight]

Like many here, I maxed out my childhood Mac. It's an LC III where I purchased all the upgrades that didn't cost an arm and a leg. Cut to a month ago and I finally got around to recapping the mother board and PSU. That went successfully. When testing I added one thing at a time to ensure I could hear a startup chime: I added the RAM, test passed; VRAM, test passed; FPU, test passed, and then I added my Apple LC PDS Ethernet card and nothing, not even a chime or death chime. It messes it up to the point where you need to wait for the PRAM to reset before it goes back to normal (I didn't have a battery installed at the time). I did some research and it seemed one couldn't have the FPU occupied and PDS slot at the same time from some discussion on StackExchange (https://retrocomputing.stackexchange.com/questions/1406/why-do-mac-lc-network-cards-take-an-fpu).

So, I concluded that I would need the Asante LC Ethernet card that has an FPU slot, but I got a BlueSCSI v2 for it and wanted to see how well that works. It works okay, but it is slow (but much faster than a 28.8k modem, at least). It seems like if the connection drops, it results in me needing to force quit apps which throws the whole system out of whack where telling the Mac to restart results in Finder getting stuck, eventually resulting in a hard freeze to where I have to do a Control-Apple-Power On to reboot. It sort of makes me want to avoid getting the Mac online, but I really want to use ircle, FTP, and maybe Hotline.

I got to looking deeper into getting an LC III with FPU an Ethernet card and came across this video:

. They got a Farallon card that doesn't have an FPU socket. They too have an FPU installed on the motherboard. At first, I was thinking, "Poor guy, their Mac won't even POST," but then they got the startup chime and booted. So, what the heck? The person in the YT video says that it was manufactured 5 years after the LC III, so maybe it is designed to co-exist? As far as I can recall, I don't think I have ever tested that Ethernet card. I've not been able to test the Mac with the card without the math co-processor installed since I didn't have a PLCC extractor, but now I think I may extract the FPU and see if the card even works!

Any guidance is greatly appricated!

be careful doing this, as you may damage the FPU or socket, but try extracting it with a flathead screwdriver, pry on each side where the PLCC extractor would go and pop it out

 

[DannyMac]

I should have said that I did purchase a PLCC extractor after I concluded that I would most likely break something if I tried to remove it that way, but at the time I figured I couldn't have it both ways and would rather have the FPU to give that old 68030 the most power it could possibly have. How is your LC III configured, do you have an Ethernet card and math co-processor installed simultaneously? (you say you have one in your signature)

 

[Nixontheknight]

My LC III ++ happens to have that Farallon ethernet card that doesn't have the FPU socket, and it has an FPU installed in the socket on the logic board (33MHz part because I overclocked my LC III to 33MHz from the stock 25MHz)

 

[DannyMac]

Thanks, two data points (for such an old Mac with the same configuration) makes me feel confident enough to pull the trigger on getting the Farallon. I've also overclocked mine. So mine is an LC III+ with FPU, 768K VRAM, 36MB of RAM. I may try pulling the FPU and seeing what happens with the card I do have just to know if it's good or not.

BTW, did you put a heat sink on your 68030 after the overclock?

 

[Nixontheknight]

I kind of put it off, because I had a set on Amazon saved for later, but the listing kind of disappeared off the face of the earth before I could buy it

 

[Fizzbinn]

I have a recapped LC III (with the III+ 33MHz mod) that I put a FPU on the logic board and have a PDS Ethernet card in that works just fine. The PDS Ethernet card is a Asante Macon that does have a space for a FPU but it's empty.

It does seem like a bad idea to have an FPU installed on the logic board and on PDS Ethernet card but I don't think its true that you can't put a FPU on the logic board if you are using the PDS slot.

I know I have some Apple branded LC PDS Ethernet cards, I think one with a 10base-T ("normal" Ethernet) connector and one with a AAUI port that needs a 10base-T transceiver dongle. Which one are you using?

Were you able to test with the FPU chip removed from the logic board and your Apple PDS Ethernet card installed?

 

[DannyMac]

@Fizzbinn The card I have is the Apple 10base-T. I've not had the chance to test the card without the FPU present yet. I'll give that a try before I install the Farallon card that I ordered. I'll report back once I know more.