7 Jul
2001
7 Jul
'01
1:46 a.m.
We didn't have to modify the motherboard, just move
some jumpers for clocks
and such, though we did have to saw a hole in the disk bay to accomodate the
fan, since the card had been overclocked. Took a whole day, and goes to prove
how cramped the A3000 is.
The '060 does a much better job at handling heat than the '040. In its
original 50 MHz state, it only had a small heatsink, whereas a small fan was
added when it was overclocked to 60 or 66 MHz.
That's cool. I didn't realize that the '060 ran so much
cooler than the '040. I may have a line on a MK II that's available
myself, which is why I asked. I'll never try to put an A3640 in
another A3000! The poor machine never worked quite right after that.
What INT2 mod, BTW?
The mod to add the missing int2 interrupt line to the A3000's
CPU slot. I guess it's only needed for the Cyberstorm's with SCSI
controllers, like the MK III. It involves running a jumper wire from
pin 21 on the CIA at U350 to pin 82 on the CPU slot, CN606. It's
done from the bottom of the board, so the whole mainboard has to be
removed. I've done that before to replace the clock battery and that
takes a bit of work. Supposedly that interrupt line was left out
because C= didn't want 3rd party vendors hanging I/O off of the CPU
slot, but to use the ZorroIII bus instead and that's what the line is
used for. Both the A2000 and A4000 have that interrupt on the CPU
slot though.
Perhaps am I just spoiled by Amiga performance, but all
my Mac activites under
emulation have been unbearably slow. Mind you, nowadays I think that my (68k)
Macs are just as slow. It's quite amazing to think that my Centris actually
runs at a higher clock speed than my A4000.
At the time I was using Shapeshifter though I only had a Mac
Plus and a Classic II, so it ran faster than either of them and it
was also in color. Now my little Color Classic offers plenty of
advantages over Shapeshifter, plus it's CPU has been upgraded to a
33mhz '040, so it's also faster than the A4000.
Jeff
--
Collector of Classic Microcomputers and Video Game Systems:
Home of the TRS-80 Model 2000 FAQ File
http://www.geocities.com/siliconvalley/lakes/6757