Smallest (physical size) Machine to Run 7.6.1?

[waynestewart]

For a CC, a 575 is quite an upgrade but if you do a 6500, you can also install a G3 card. Even without the G3 card a 300mhz 603e is pretty fast. If I was using it more I'd try soldering the missing RAM chips onto the motherboard. But as is 8mb more isn't that important

 

[jsarchibald]

I hadn't even seen your post! Must be a popular thought!

 

[trag]

Thank you, Wayne. That will be very helpful.

 

[trag]

if you do a 6500, you can also install a G3 card. Even without the G3 card a 300mhz 603e is pretty fast. If I was using it more I'd try soldering the missing RAM chips onto the motherboard. But as is 8mb more isn't that important

What, what what!?! There's a position to install another 8 MB on the logic board?

That implies circuitry which will be capable of handling at least 32 MB more, if not 64 MB. Of course, I don't know what the memory map limit is.

Do you have a link to information about this missing 8 MB?

It's crazy that the thing has all 12 address lines and is capable of 12 X 10 (32 MB/bank) and 11 X 11 (also 32MB/bank) but not 12 X 12 (128MB/bank) or even 12 X 11 (64MB/bank) addressing.

 

[waynestewart]

A 6400 has 8mb soldered onto the motherboard. There isn't any soldered onto the 6500 motherboard but the solder pads are there. I'm assuming that if you solder on 8mb that the maximum RAM will be 136mb like the 6400

 

[trag]

Ah, I see the pads. Must use 16 bit wide DRAM, which has got to be hard to come by. It suggests an interesting hack, though. The data lines and address lines are going to be common from DIMM to DIMM to soldered-down-RAM. The only distinct signals are going to be amongst the RAS, CAS and/or Bank(0) signal.

So, if I sort that out, install a 128 MB DIMM in one of the DIMM sockets, cut the distinct traces to one bank of 64MB on the DIMM and wire those traces to the corresponding signals on the soldered-down-RAM pads, then, in theory, one should get at least another 32 MB of memory and maybe another...

Oh, I need to go read the Hardware Developer Note again. That may not work at all, at all. I think the machine already does two banked RAM but just won't address more than 32 MB per bank. So that would shoot down my clever idea.

On another front, when you buy stuff on Ebay, don't wait four months to open it. I finally unpacked my PM6500/300 tonight. It's a 250MHz. Stinkin' Ebay sellers.

In his defense, I think it was careless ignorance, rather than intentional fraud, but the fellow had it listed as 330MHz at first. I emailed him, pointed out that didn't exist, he changed it to 300MHz. The jerk could have just plugged the machine in with a monitor attached. Or pulled the logic board. There's a label right there. Sigh. I guess 50MHz is not that big a difference, and I didn't pay a lot for the thing, but it's irritating.

Time to see if it's too late to leave feedback....

 

[highlandcattle]

Any updates? I find this a mighty interseting project

 

[trag]

Any updates? I find this a mighty interseting project

Nope, just a little more stuff that I've bought. But buying stuff isn't doing the project. When I actually get going, I'll post over in the Hacks forum and maybe link from here.

I picked up a pair of 64MB EDO DIMMs from OEMPCWorld or OEMPCmemory or something like that. $20 each, whcih isn't too bad these days and shipping was free. I found a 32MB EDO DIMM in my memory box. So if I try to add more memory to the logic board, I can use either that DIMM or the chips from it. The maximum memory per bank is 32MB in the 6500.

I got the 320GB PATA drive to put in my Mac Mini which will free up its drive for this project. Although I may bump the Mini's drive to the AppleTV and use the ATV drive here. IIRC, they're 160GB and 40GB respectively.

Still, I haven't started actually doing the work, other than preliminary looking at Apple documention.

 

[Theretrogamingroom]

According to lowendmac, a Mac Classic II can (Barely) run 7.6.1. However, you would be pushing the machine to the limit.

 

[Dennis Nedry]

The logic board in the Classic II is INCREDIBLY small. I held one in my hand and I could not believe that I was basically holding a fully-functional Macintosh. It is much smaller than a 5xx Mac logic board.