Atari 520ST(M)
4MB RAM Expansion

Tested on C070243 Rev.I , your mileage may vary.

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Important

1. The board needs fixing with a bodge wire

2. The expansion board must be installed
   directly onto the motherboard.
   

   Using sockets won't leave enough
   clearance for the keyboard

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BOM

	Component	Value	Size	Package
	C1 - C6	100nF	0805
	R1 - R2	68Ω	0805
	R3	33Ω	0805
2x	5118160 DRAM			SOJ42

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Installation

• De-solder the existing RAM.

• Solder the expansion board in place.

• Solder the four wires from the expansion
  board to the motherboard.

  Signals: MAD9, CAS1L, CAS1H, RAS1

  MAD9 can usually only be found on the MMU

  The CAS & RAS pins can be soldered to on the
  underside of the motherboard as well as,
  on some boards, on the topside as well.

  Name	MMU Pin
  RAS1	18
  CAS1L	21
  CAS1H	22
  MAD9	64