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Amiga Technical References

Amiga 4000 Desktop Jumper Settings
Function:            Jumper:  Setting:  Description:
CLK90 Clock Source   J100:1-2  X-X X    Internal (020/030)
                     J100:2-3  X X-X    External (040)

CPU Clock Source     J104:1-2  X-X X    Internal
                     J104:2-3  X X-X    External

ROM Speed            J151:1-2  X-X X    200ns
                     J151:2-3  X X-X    160ns

CHIP RAM Size        J213:1-2  X-X X    2 Meg
                     J213:2-3  X X-X    8 Meg (yeah right)

Enable Second        J351:1-2  X-X      No Second internal floppy drive
Internal Floppy                         or 1.76MB floppy drive
                     J351:     X X      Enable second internal floppy drive
                                        880k as DF1:

Redirect DF0:        J352:1-2  X-X X    Internal: DF0: and DF1: internal
                                                  DF2: and DF3: external
                                        External: DF2: and DF1: internal
                                                  DF0: and DF3: external

Enable DSACK         J850:1-2  X X      DSACK enable. Required if CPU is a
                                        68020. Also requires U860 and U152.
                     J850:1-2  X-X      No DSACK.

RAM Size             J852:1-2  X-X X    RAM size 1 Meg x 32
                     J852:2-3  X X-X    RAM size 256k x 32

Select NTSC/PAL      J212:1-2  X-X X    Select NTSC
                     J212:2-3  X X-X    Select PAL

VBB\MA10             J214:2-3  X X-X    Supplied VBB to ALICE
                     J214:1-2  X-X X    ALICE supplies MA10 for 8 Meg CHIP
                                        (NO it DOESN'T WORK!)

Select Sync on Green J500:1-2  X-X X    Sync on Green Disabled
                     J500:2-3  X X-X    Sync on Green Enabled

LISA Sync            J501:2-3  X X-X    Default

Select DAC Sync      J502:1-2  X-X X    DAC Syncs on Green
                     J502:2-3  X X-X    DAC used standard signal

Copyright 2000 Amiga Auckland Inc. All rights reserved.
Revised: August 13, 2005.