Not rare but unusual thread. — #35

Post #35 by JDW

Source Forum	68kMLA
Category	Peripherals
Post Date	Tue, 3 Nov 2009 - 00:02
Original URL	https://68kmla.org/bb/threads/not-rare-but-unusual-thread.12404/

Post

I'm not pulling up any old info on those NewLife upgrades, but I did remember them from years past. Here's an excerpt from Jeff Walther's 2003 post about the NewLife:

I was fond of the Newlife upgrades for the 512KE because RAM was very expensive back then and the Newlife upgrade has eight SIMM sockets.

So, on a Mac 512KE you could get to 4 MB by installing two expensive

(like $80 each) 1 MB SIMMs, and six inexpensive ($5 each or free)

256K SIMMs. That added to the RAM on the motherboard took the

machine to 4 MB.

The Newlife upgrade had its own 68000 CPU on board but it was not any

faster than the Mac CPU. The guys at Newlife explained that it was

just easier to put the Mac CPU to sleep and have their own CPU on

their board than it was to arrange to use the Mac CPU. 68000 chips

were under $10 back then, IIRC.

Newlife also had an upgrade which I could never afford. It installed

in a Plus or 512KE and provided a fast 68030, memory expansion, SCSI

and video out. I really wanted that one. I think it's memory

could go to 16 MB. The Mac ROM didn't support more than 4 MB, but

the way I understood it, the extra memory became a RAM disk, and then

one took advantage of the 68030's PMMU to implement virtual memory

which turned around and used the RAM disk for its scratch space, thus

turning the extra RAM into available RAM in an bass-ackwards kind of

way. One had to have Connectix's "Virtual" to make this work.

But getting back to the Dove MacSnap boards, I am most interested in knowing the specific differences between the MacSnap 5.0 "RAM upgrade" (without SCSI, uses the stock 64k ROMs) that was made for the Mac 512k. It came in two flavors: 1MB & 2MB. How other than examining the markings on the RAM ICs can one tell the difference between the 1MB and 2MB boards?

And would anyone happen to have documentation for the MacSnap boards? There is a DIP switch on top and without the documentation it's impossible to know what the correct settings should be.

UPDATE: Here is an original Dove ad talking about the MacSnap products.