--- Steve Conrad <[EMAIL PROTECTED]> wrote: > Speaking of FPU's I was wondering how a 68881 and a > 68882 differed. > From a list of Macs that I have it appears that only > the II came with the > 68881 (built-in) and that it could be added to the > LC via an FPU card.
Dunno exactly, but the 68882 is better and can be fitted directly in place of the 68881. Some of the Mac II machines came with a chip called the AMU instead of the PMMU chip and cannot use virtual memory unless it's swapped for a PMMU. Another useful Mac II upgrade is the ROM and SWIM upgrade. After Apple relesed the Mac IIx they sold a kit that consisted of the Mac IIx ROM (I'm pretty sure there wasn't anything specialized for the Mac II about it) and the SWIM chip to replace the IWM chip. The ROM replacement fixed the bug where only 1 meg SIMMs would work in Bank A and in conjunction with the SWIM (Super Woz Integrated Machine) replacement for the IWM (Integrated Woz Machine) chip allowed for the use of the 1.44 meg floppy drives. But even with the new ability to use more RAM and 1.44M floppies, it still had the 68020, PMMU and 68881 trio of chips. Two of those chips had to be removed to plug in the Daystar 030 PowerCache upgrade. (My manual isn't handy so I can't lookup if it was the CPU and FPU or CPU and AMU/PMMU.) At any rate, dropping in the PowerCache eliminated the problem of not having virtual memory on AMU equipped Mac II boxen. Before the debut of the IIci, DayStar made seperate models of the 030 upgrade for each model of Mac. The *Universal* 030 PowerCache plugs directly into the IIci/IIvi/IIvx/Performa 600 cache/PDS or into an adaptor that provides a IIci etc compatable slot on Macs without one or converts the IIsi and SE/30 slot to the IIci version. ===== "Why do Zik-Zak Burgers come in plastic packs? Some of the plastic rubs off on them and increases their nutritional value!" Max Headroom __________________________________________________ Do you Yahoo!? Yahoo! Web Hosting - establish your business online http://webhosting.yahoo.com -- Vintage Macs is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Enter To Win A | -- Canon PowerShot Digital Cameras start at $299 | Free iBook! | Support Low End Mac <http://lowendmac.com/lists/support.html> Vintage Macs list info: <http://lowendmac.com/lists/vintagemacs.shtml> The FAQ: <http://macfaq.org/> --> AOL users, remove "mailto:"; Send list messages to: <mailto:[EMAIL PROTECTED]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive: <http://www.mail-archive.com/vintage.macs%40mail.maclaunch.com/> Using a Mac? Free email & more at Applelinks! http://www.applelinks.com
