Would this work?

[LCGuy]

Ok, I know this is more a PC question than a Mac question, but considering its rather Mac-specific (as far as LC630 DOS cards go, anyway), i'll put it here...

I have an LC630 with a DOS card, which has its standard Cyrix 486DX2/66 chip. I have, sitting here, a 133 Mhz AMD Am5x86 chip. Will this chip work on the LC630 DOS card, or not? I know that it would work fine on a standard 486 PC motherboard, but considering that this is not a standard dime-a-dozen 486 motherboard, and instead a hard to find DOS card (mine's the only one i've ever seen, and I don't know when i'll see another), I want to make sure I can do this without having the magic smoke escape from either the chip or the board.

 

[Byrd]

Sadly it won't work - the 486/66Mhz CPU you have is 5V, and the 5x86 CPUs run at 3.3V (ideally 3.45V). I used to run a Kingston Turbochip 5x86 133Mhz upgrade in my LC630 DOS machine, which had a little PCB on the board to regulate/increase voltage to 5V.

This CPU was fast but Windows wouldn't install - I'm assuming the DOS card didn't have the proper BIOS CPU microcode support to run it properly. It was fine for DOS games though.

Your best bet would be a Intel Overdrive 486DX4-100 CPU, which seem to kick around in many old 486 towers. I've since scrounged around for one of these and have installed it in my LC630. Windows 98 SE and everything else now run without issue. If I ever find another LCGuy, it's got your name on it

It is unusual, the LC630 DOS card - especially how it piggybacks off the '040 socket and it doesn't look terribly stable perched up on there. Once you've got this card + Commslot ethernet it all looks a bit of a mess Clearly not Apple's finest motherboard design!

JB

 

[LCGuy]

Ah, I expected as such Oh well, thanks anyway And thanks for the offer

As for my DOS card, its perfectly stable, its screwed to the board via some standoffs. And yes, my 630 actually not only also has a CS Ethernet card, but also an Apple Video System, and both RAM slots on the Mac side are full, so yes, I can definately see what you're saying there - you can hardly see the LB anymore, really!

For the record, in my collection of parts, I happen to have an Intel 486DX2/66 chip. Since Intel used a different design to Cyrix, would there be much, if any of a performance increase by switching to the Intel chip?

 

[Byrd]

Cyrix have a special technology where their CPUs run at least 50% slower than other brands I used to happily use an AMD 5x86 @ 160Mhz on an ASUS VLB board, and "upgraded" to a Cyrix P150+ CPU - don't know why I bothered

I think early 486 CPUs are mostly all the same though (licensed from Intel?), but as long as your Intel 486/66 is 5V, I'd put this in over the Cyrix. A little heatsink on top wouldn't go astray either.

JB

 

[Gil]

If anyone is interested, I have an old Pentium MMX 166Mhz from an old computer. No idea if it will work, just throwin it out there.

 

[LCGuy]

Haha, yeah...the reason why Cyrix chips were slower than Intel and AMD, IIRC was because they came up with their own designs, whereas AMD simply licensed Intel's designs and repackaged them under their own name, since they were basically the same chips, there wasn't too much of a performance difference.

As for Cyrix, well, yeah, I've always heard that they are, as Jeremy Clarkson would put it, complete rubbish. The DOS card certainly is a lot slower than the 486's that I remember using, although I'm not sure if thats due to the Cyrix chip, or the oddball architecture that its sitting on. For the record it has 16MB of RAM and is running Windows 95B.

Either way, I just remembered after I made that post that my 486DX2/66 is actually an Overdrive, and I'm pretty sure its 5V. Might have to give 'er a try...hopefully it'll make a difference in performance.

 

[Temetka]

It will.

I suggest more RAM for the DOS card, Windows 95 will thank you.

 

[LCGuy]

Yeah, I'd love to put more RAM in, but there's only one RAM slot there, and I don't have any spare 32MB SIMMs. :-/ Not good, surely they could've made it a bit bigger so that they could shoehorn on another SIMM slot for the DOS card.

 

[equant]

Would a simm-tree work in it?

 

[madmax_2069]

Would a simm-tree work in it?

your talking about one of these, it might if there is room.

http://cgi.ebay.com/2X72-Sims-Memory-Stacker-NEW_W0QQitemZ200078180755QQcmdZViewItem

 

[LCGuy]

And where the hell would I get one of those?

 

[madmax_2069]

i would try that simm stacker if its the proper pin count, its a good possibility that it would work, it would almost be worth a little over $9 to find out.

 

[equant]

And where the hell would I get one of those?

Madmax's ebay link is what I was thinking about. I've seen them with at least 4 slots. Last time I googled (< 1 year ago) I found a few options. Now I'm coming up with nothing. Maybe I'm not using the right keywords. I know I've heard them called a simm tree and simm saver. That's all the help I can offer.