MBX 1200 results
An MMU is a "Memory Management Unit" it used, on the Amiga, mainly to copy
the kikstart ROM to 32 bit RAM to increase speed (Old 16 bit ROM's in
A500's and A2000's is substantially slower than 32 bit RAM.)
An MMU can also be used by a computer to handle "Virtual Memory" The Amiga
OS doesn't support this type of thing yet (there is at least one 3rd party
software package that does) However, in my opinion I don't want virtual
memory on a home machine. I had a whole class dealing with this subject
when I was in college, so if you want me to go into more detail, I will.
Yes, the 68EC020 is a "little" faster than a stock 68020 with a MMU
(68851?), but not all 68020 machine's have an MMU, it is a separate chip
that the 68020 can use… The 68EC020 can't drive the same MMU basically
becasue of it not being signal compatible with a 68020. Which in the
A1200 class of machine, is no handicap, in fact, it's an advantage becasue
of cost.
The MBX1200 is just an expansion board the plugs into the belly slot of
the A1200, and has a 68881 FPU chip on the board (as well as a SIMM
socket, that I have 8 megs of 32 bit RAM in.
Software has to be written to take advantage of the MMU (Any MMU on any
Amiga) So It'll only speed things up that are written for it. The 32 bit
fast RAM that I have added speeds up the whole machine though (about 75%)
AGA and 68881 don't have anything to do with each other, older Amigas can
have the 68881, or 68882, that's not a new thing.
I almost bet that having an FPU will not speed up DPIV, but don't know at
all— I don't have DPIV, though most paint programs don't use a FPU
becasue of not needing one (any math they do is all integer math and an
FPU doesn't help that.)
I bought the MBX1200 mail order for about $150…
3's a tough question, but to say it simply yes if the processor and bus
speed is the same, and the memory path is doubled. On the A1200, the path
is double, the clock speed of the CPU is double, and the CPU is more
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