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6/10/85
BIG MAC DATA SHEET
The Big Mac is a high performance Macintosh whic.h can be
used as both a Macintosh and as a work station. It is implemented using
three 500 gate bipolar ~Jate arrays and one 1200 gate cmos gate array.
Display: 1024 x 800 8IW display, 60 Hz refresh, 70Mhz dot rate
CPU: 68020 with option for 12M, 16M, and IBM clock rate
FPU: 68881 as floating point !coprocessor
NIJIU: Custom M~I1U with 4Gb ,address space, 64 entry TLB with
4Kb pages which offers a working set size of 256Kb.
Virtual address space is configurable from 16M to 4Gb.
The MMU~ supports write and execute protection and
,c--
dirty bits for ea-ch-page. - ~"~----./ UV'iJ;,-u_~ ~
<{/
. 6 I
Memory: 2 Mb of DRAM on main logic board using 256Kx1
Separate video memory using 64Kx4
256Kb of ROM using two 1M parts
RAM is limited to 10Mb max
DMA: 68450 (use 68440 if no 2nd SCC) with support to access
the full 32 bit address space.
1/0: Two see chips (ie. four serial ports)
SCSI port for internal 20Mb hard disk and external devices
Double sided SONY, IWM chip interface, option for 2nd SONY
Macintosh compatible sound with SONY sound chip.
Front Desk Bus for keyboard, mouse, etc.
Real Time ()Iock with battery backup
Soft power on/off.
Slots: Four 1/0 Slots with access to 32 bit address and data bus
Two Memory Expansion Slots
Rich Poge
61G MAC LOGIC BLOCK DIAGRAM 6/2/85
68440
CPU 68020 DMA OR
68450
1\1-1\4
FOUR
FPU 68881 I/O
SLOTS
0, 031-D24
GATE ARRAV-3
SOUND &. VIDEO
ROM'256Kb
TIMING
GATE ARRAV-1A SCC
NUX 16 TO 8 IWM
VIDEO COUNTER SCSI
CLOCK
FRONT DESK
MMU WITH 64
ENTRV TLB
VIDEO RAM
(8 - 64Kx4) ,
GATE ARRAV-1B GATE ARRAV-4
NUX 1B TO 9 NUX 20 TO 10
. .
CSC :F109 :F161
~---..
SND COUNTER
MODE -_
=1 ....
SND COUNTER
70M 35M
CPU GATE ARRAV-2
7.8M CLOCK MAIN RAM EXPANSION RAM
GENERATOR (32 - :>56KxO (32 - 1Mx1)