Amiga A4000 - Chapter 3 Processor Expansion; Amiga Bus Expansion

3-2 Processor Expansion
processor. Up to 2 MB of Chip RAM and 16 MB of Fast RAM may
be installed in the A4000's SIMM sockets.
RAM
can be added quickly and inexpensively by installing standard
SIMM units in the five motherboard sockets. Additional memory
can be added using the Amiga bus slots, if desired. Replacement
processor modules also may accommodate RAM.
Processor Expansion
The A4000 central processing unit (CPU) is mounted on a
removable processor module that plugs into the 200-pin CPU
expansion slot. This is a "local bus" slot provided specifically to
support expansion options that must be tightly coupled to Amiga
motherboard memory.
The standard processor module contains a 25 MHz Motorola 68040
series microprocessor. These processors use the Amiga's 32-bit
RAM efficiently for very
high speed operation.
To
upgrade to a faster processor, additional high-speed memory, a
digital signal processor (DSP), or other performance enhancements,
the original A4000 processor module is removed and replaced.
Amiga Bus Expansion
There are four lOO-pin general purpose expansion slots in the
A4000. These use the Zorro III Amiga expansion bus, which yields
high performance with a wide variety of expansion devices,
including, for example,
high resolution framebuffers, video and
audio digitizers, SCSI interfaces, RAM, and multi port 110 boards---
all within the main chassis of the computer.
The Zorro III slots are 100% compatible with the many Zorro 11
expansion boards already available for the Amiga. Use of Zorro 11
expansion boards does not lower the performance of Zorro III boards
that may also be installed.