MicroBotics MBX 1200z User Manual

User's Guide to
MBX 1200z
FPU, 32-Bit Memory, and Clock
®
for the Amiga
from
MicroBotics, Inc.
1251 American Parkway, Richardson, Texas 75081
(214)-437-5330 (Central Time Zone, 0900 to 1700 hrs.)
"MBX 1200" and "MBX 1200z" are MicroBotics' trade names for its FPU/Memory
devices for the Amiga 1200; "Amiga" and "Amiga 1200" are registered trademarks of
Commodore/Amiga
COPYRIGHT 1993, MICROBOTICS, INC., ALL RIGHTS RESERVED
GENERAL DESCRIPTION
AND ORGANIZATION
MBX 1200z is a high speed floating point and memory card
which employs the Motorola 68881 as a math co-processor
chip running at a 14.3 MHz clock. Optionally, 25 or 50
MHz 68882 can be supported. Also supported is the addi-
tion of up to eight megabytes of 32-bit wide RAM via the
installation of an optional SIMM (Single Inline Memory
Module) bearing 1,2,4, or 8 megs of memory. Finally, the
board supports a battery-backed real time clock circuit to
provide system date and time for file date-stamping.
STARTING INSTALLATION INSTRUCTIONS
Shut down your Amiga 1200 and remove the power cord
from the back of the Amiga. Turn your 1200 over on its
keyboard so that you can easily access the hatch in the
bottom of the machine. Open the plastic hatch on the bot-
tom of the Amiga. In good light, closely examine the physi-
cal layout of the expansion bay in your Amiga.
BASIC MBX 1200z INSTALLATION
1. Examine your MBX 1200z (holding it by its edges) paying
particular attention to the jumper settings on your board
(jumpers are little black plastic blocks that slip over some
of the upright, brass colored pins on your board; they "tell"
MBX 1200z some of its configuration information). Take a
look at the MBX 1200z diagram in this documentation.
Make sure your jumpers are set correctly.
2. Keeping the component side of the board facing out-
wards from the Amiga, insert the MBX 1200z into the
expansion bay. Note that you'll have to maneuver it into the
bay since the connecter end is wider than the bay opening.
3. Line up the black edge-card connector with the expan-
sion card-edge on your Amiga. Lightly press it onto the card
edge and make sure it is properly lined up. Then firmly
press it completely onto the card edge.
4. Replace the plastic hatch and turn your Amiga back
over. Your MBX 1200z is now ready to use.
INSTALLING SIMM MEMORY
If you or your dealer are installing a SIMM into MBX 1200z
this can be done without removing the MBX 1200z from the
Amiga. Make sure the power is off and the power cable
removed from the back of the Amiga before proceeding.
Handle the SIMM by its side edges. Rest the card edge side
of the SIMM in the SIMM socket with the notched side of
the SIMM on the "keyed" side of the connector. See the dia-
1200
page 1— MBX 1200z USER'S GUIDE, Edition 1.1
gram. Press down firmly on the top edge of the SIMM with
both thumbs; then press the SIMM forward to snap it into
place (pushing it past the metal retaining clips). Should you
need to remove the SIMM, simply use your thumbs to
squeeze open the metal clips (pressing them outwards
towards the side of the SIMM connector). The SIMM will
pop up when released.
If you or your dealer are purchasing a SIMM from a source
other than MicroBotics, Inc., you must be certain to get the
correct type. MBX 1200z does NOT use the common, 8-bit
SIMM as found in the Macintosh marketplace. Rather it
uses the same sort of SIMM as used in the Amiga 4000.
This is a 72-pin, 32-bit wide SIMM. MBX 1200z needs only
an 80ns SIMM in order to operate at zero wait states. You
can use a 70 or 60ns SIMM but these may cost more for no
additional benefit. The following is a list of Micron part
numbers for the correct SIMM. You can use the equivalent
parts from any good quality manufacturer.
MBX 1200z SIMM SPECIFICATION; 80ns, 72-pin "wide-
body" SIMM organized N-megabytes x 32 bits. For example,
Micron MT8D25632 (one megabyte); MT16D51232 (two
megabytes); MT8D132 (four megabytes); and MT16D232
(eight megabytes).
JUMPER SETTINGS: If memory is installed you must check
the three jumper blocks on J1. See the diagram for details.
Note that if no memory is installed, the first jumper must
be ON (in "TEST" mode) for the board to work properly.
MATH COPROCESSORS
The Motorola Floating Point Units (FPU's) 68881 and 68882
are supported on the MBX 1200z. A synchronously clocked
14.3MHz 881 is standard. Optionally, the board may be
supplied with a 25 or 50MHz 68882. Note that there is only
a minor performance difference between the older 68881
and the 68882 at the same clock speed (about 5%) unless
the software is written with the 882 especially in mind (lit-
tle is). An FPU upgrade kit (consisting of the math chip and
appropriate crystal) is available from MicroBotics. Unless
you have a PGA chip pulling tool, it is best to leave the
removal of the installed math chip to a technician. The
operation of a properly installed math chip is transparent
to the user running under AmigaDOS 3.0. The FPU pro-
vides a significant performance increase when running soft-
ware which is computationally intense; particularly that
software which makes heavy use of transcendentals and
floating point math. If your application software offers you
a choice, be sure to operate it in 881/882 mode for good
performance.
IMPORTANT: Note that the math chips compatible with
MBX 1200z must be PGA (Pin Grid Array) style.
JUMPER SETTINGS: When running clocked from the moth-
erboard (14.3MHz) the J2 Jumper block is on the upper two
pins (see diagram). When a faster math chip and oscillator
are installed, this jumper is moved down to the lower two
pins. Do NOT overclock a math chip —doing so may damage
the chip, cause inaccuracies, and will void your warranty.
1200z REALTIME CLOCK
The MBX 1200z also provides a realtime, battery backed
clock (although the product may also be sold without the
clock hardware installed— check your board). This clock
uses the AmigaDOS Date and SetClock routines. See your
DOS manual for details. The coin-cell lithium battery will
last a very long time. Should you ever have to replace it,
use an equivalent lithium cell (3 volts; CR 2032). Such bat-
teries are widely available. Be sure that the "+" on the bat-
tery is facing outwards.