9
ADDING AN FPU TO THE BOARD
The AMITEK A1200 Expansion board can also accommodate an FPU (Floating Point
Unit) to increase performance of maths calculations. This type of co-processor works
in parallel with the main central processing unit, taking over much of its arithmetic
work with real (i.e. floating point) numbers. It can be particularly important if you
intend to do a great deal of number crunching work with spreadsheets, complex
equations or calculus. As your Amiga handles all low level operations in terms of
mathematics, an FPU can even speed up tasks such as simple animation and
complex 3D image generation where the activity of the maths co-processor makes a
critical difference in the calculation of graphics formulae.
Your new AMITEK RAM expansion board has a PLCC 68881/2 (rather than PGA)
type of FPU socket.
The large range of FPU’s run at different rates which are measured in
MH
Z
: the higher
the number, the faster the speed. An FPU may also come with a crystal oscillator that
can regulate the operation of the FPU. If, however, you do not have a crystal, you
must run the FPU at the same time speed as the machine (14.3
MH
Z
).
There are various types of processor which you can install on the AMITEK board, all
of which are distinguished by their individual processing speeds. The available chips
run at 16
MH
Z
, 20
MH
Z
, 25
MH
Z
, 33
MH
Z
and 40
MH
Z
- the latter of which is the top of the
range for most RAM combo boards. You may find one is supplied as part of the
product that you have purchased, or you can buy one from your local Amiga dealer.
Figure 3.1 - Positions of FPU and Crystal
Positioning Mark
Positioning Arrow
Floting
Point
Unit
Positioning
Mark
Crystal Oscillator