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3.8.2. What's different on the Lisa 1 I/O board?
The Lisa 1 uses two 860KB 5.25" Twiggy drives instead of the Sony 3.5" 400K drives. When Apple provided the upgrade from Lisa 1 to Lisa 2, resistors R41 (3.3KOhm) and R47 (1KOhm) were cut on the I/O board, the I/O ROM was changed from version 40 to version 88.
(Also, the two Twiggy drives were replaced by a single Sony 400K drive which interfaced with the LisaLite board, and the face plate was changed.)
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