LEGO Set

Robotics Invention System Upgrade Kit (1.5)

3803-1

Released: 1999 · Parts: 70 · Theme: RCX

Robotics Invention System Upgrade Kit (1.5) (3803-1) is a RCX LEGO set released in 1999 with 70 pieces. Browse the parts list, minifigures, and verify loose bricks with our free scanner. Collectors browsing RCX sets use this inventory to verify loose parts, compare color variants, and read official build manuals without downloading PDFs. This set includes 25 unique part types.

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Buying checklist

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Release year

1999 (27 years ago — may be retired)
Catalog scale

70 parts listed · 25 inventory lines tracked
Minifigures

No minifigs in inventory (brick-only or Technic set)
Build manual

No digital manual in our catalog — check the box tab or LEGO.com
Gray era

Pre-2004 set — may use old light/dark gray instead of bluish gray
Shipping weight (est.)

~127 g for parts inventory (excludes box/minifig packaging)
Before you buy used

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Related sets in this theme

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9-Volt Touch Sensor and Leads

9911-1 · 2004 · RCX

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Touch Sensor with Cable

9757-1 · 1999 · RCX

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RIS 2.0 Basics Kit

KB565-1 · 2004 · RCX

1 parts

Robotics Invention System Upgrade Kit (2.0)

3805-1 · 2002 · RCX

1 parts

Temperature Sensor

9755-1 · 1999 · RCX

1 parts

Market value

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