PJRC.COM Offline Archive, February 07, 2004
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You are here: 8051 Tools Development Board Old Versions Rev 2 (1997) Schematic Search PJRC

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8051 Dev Board, $79
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Rev 4
New Rev 4 Board
A newer version (Rev 4) of this circuit board is available. Rev 4 includes a faster CPU, more memory, more I/O and an optional LCD. We recommend you use Rev 4 for new projects. Even though this older board is no longer available, we are keeping these old pages on-line for reference to assist people who purchased or build the older version.

Schematic Drawing

This is the complete schematic for the development board. Address and Data bus wires are drawn separately (not in a bus), so that it's easy to color over them on a printout, if you choose to manually connect the wires. It really is easier to buy a bare circuit board, though.

This design and its schematic have been placed in the public domain. They are distributed in the hope that they will be useful, but are provided without any warranty, not even a warranty of merchantability or fitness for a particular purpose.

schematic drawing
Also, the original (ugly) schematic that Forrest used to create the circuit board is available for download, as a postscript file, or a bitmap image.

Parts List

5C3,C4,C5,C6,C7>1uf, 16V (for the MAX232)
1C8100uf (>6.3 Volt)
1C9100uf (>16 Volt)
3C10,C11,C120.1uF (Decoupling Caps)
1D113V Zener, Digi-Key # 1N4743ACT
1D25.6V Zener, Digi-Key # 1N4734ACT
2D3,D121N4001 Rectifier Diode
8D4,D5,D6,D7,D8,D9,D10,D11LED, Digi-Key Part # P437
8R7,R8,R9,R10,R11,R12,R13,R14470 Ohm
1U187C51 (or equiv)
1U274HC373 (Octal Latch)
1U36264 (8K x 8 SRAM)
1U4AM28F256 (Flash ROM)
1U582C55 (I/O Chip)
1U674HC138 (3:8 Decoder)
1Y111.0592 MHz Xtal
2P1, P2DB-9 Female Connector, Digi-Key Part # A2100

8051 Development System Circuit Board, Paul Stoffregen, Forrest Hudson
Last updated: November 28, 2003
Status: finished
Suggestions, comments, criticisms: <paul@pjrc.com>