Commodore Amiga A500 Technical Reference Manual page 23

Section
3.1
Designing Hardware for the Amiga Expansion
Architecture
INTRODUCTION This section gives guidelines for designing hardware t o reside on the
Amiga expansion bus. The Amiga expansion bus is a relatively
straightfonvard extension of the 68000 bus.
Hardware for the bus can be viewed as two categories: backplanes
and PICs. Backplanes interface t o the 86 pin connector of either
another backplane or the Amiga itself. Backplanes buffer the bus and
provide 100 pin connectors for PlCs t o plug into.
PIC is an acronym for plug-in card.
A
PIC
is usually a card that plugs
into the standard 100 pin Amiga connectors.
A
sub-type of PIC is a combination of backplane and PIC integrated
into one package. These combination products should follow all of
the applicable backplane and PIC rules, especially auto-configuration.
Software never sees backplanes; all expansion hardware appears t o
the software as PICs.
WARNING
These specifications represent "worst case" design targets.
Products that do not comply with these specifications can be ex-
pected t o fail on worst case production units.
Following conservative design pracbces and allowing the widest
safety margins is your best assurance against problems in the
field.