68302 CPU Board
About the 68302 CPU Board
68302 CPU Board is an open source PCB design by MarkD833, published on GitHub under the CC-BY-NC-4.0 license. It is a 4-layer board measuring 101.6 × 53.3 mm, with 37 components from 16 distinct parts.
Other key parts include the 74LS10, 74LS139, 74LS125, 68302RC and 74LS148. By type, the board carries 13 capacitors, 6 connectors, 6 diodes, 6 resistors, 5 ICs and 1 crystal.
It belongs with the retro computing designs in this gallery.
From the project
My Motorola 68000 & 68302 processors (+ SIO, PIO & MFP boards) for the RCBus ecosystem.
The processor board is designed to plug into an RCBus-80 backplane and expects to find the stack pointer and initial program counter addresses at location 0x000000 onwards.
If using latest version of the MON302 that supports ROM & RAM remapping via software then the RC102 ROM/RAM board should not be used without some hardware modification.
A note of caution when using a socketed oscillator - there is the possibility that the metal can of the oscillator could accidentally short out pins on the next board. Please be aware of this.
Main components on the 68302 CPU Board
68302 CPU Board bill of materials (BOM)
37 components, 16 distinct parts — part numbers from the project's BOM.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | 74LS10 | DIP-14_W7.62mm_Socket | U1 |
| 1 | 74LS139 | DIP-16_W7.62mm_Socket | U2 |
| 1 | 74LS125 | DIP-14_W7.62mm_Socket | U3 |
| 1 | 68302RC | PGA132 | U4 |
| 1 | 74LS148 | DIP-16_W7.62mm_Socket | U5 |
| 1 | 7.3728MHZ CXO_DIP8 | Oscillator_DIP-8 | X1 |
| 1 | CONN_01X02 Conn_01x02 | PinHeader_1x02_P2.54mm_Vertical | J1 |
| 1 | RCBUS_80PIN_68000 RCBus_80PIN_68000 | RCBus_80p_Medium | J2 |
| 1 | CONN_01X03 Conn_01x03 | PinHeader_1x03_P2.54mm_Vertical | J3 |
| 3 | CONN_01X06 Conn_01x06 | PinSocket_1x06_P2.54mm_Horizontal | J4, J5, J6 |
| 2 | BAT43 | D_DO-35_SOD27_P7.62mm_Horizontal | D1, D2 |
| 4 | LED | LED_D3.0mm | D3, D4, D5, D6 |
| 13 | 100N 100n | C_Disc_D5.0mm_W2.5mm_P2.50mm | C1, C2, C3, C4, C5, C6, C7, C8 +5 |
| 4 | 1K | R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R1, R2, R3, R4 |
| 1 | 4K7 | R_Array_SIP9 | RN1 |
| 1 | 10K | R_Array_SIP9 | RN2 |
68302 CPU Board design files
The KiCad project lives in the MarkD833/RCBUS-68xxx repository on GitHub; these links point at the commit this page was built from.
68302 CPU Board: common questions
How big is the 68302 CPU Board?
The 68302 CPU Board measures 101.6 × 53.3 mm, has 4 copper layers and is 1.6 mm thick.
How many components are on the 68302 CPU Board?
37 components, from 16 distinct parts, with part numbers taken from the project's own BOM. The full bill of materials is listed on this page.
Where can I download the 68302 CPU Board design files?
From the MarkD833/RCBUS-68xxx repository on GitHub, which has the KiCad layout, the schematic and the BOM; the links under Design files point to each one.
Can I use the 68302 CPU Board design in my own project?
It is published under CC-BY-NC-4.0, which limits how it may be reused; read the license before building on it.
More boards in RCBUS-68xxx
RC200-Dev Backplane
188 × 102.9 mm90 parts2LCC-BY-NC-4.08
RC202-68000 SIO 1
101.6 × 53.3 mm40 parts4LCC-BY-NC-4.08
RC201-68000 CPU 2
101.6 × 53.3 mm37 parts4LCC-BY-NC-4.08
68000 LBE Board
101.6 × 53.3 mm34 parts4LCC-BY-NC-4.08
68000 SIO BOARD
101.6 × 53.3 mm33 parts4LCC-BY-NC-4.08
68000 CPU Board
101.6 × 53.3 mm32 parts4LCC-BY-NC-4.08
RC107-68000 ROM RAM 1
101.6 × 53.3 mm28 parts4LCC-BY-NC-4.08
68000 MPF BOARD
101.6 × 53.3 mm27 parts4LCC-BY-NC-4.08
RC203-68000 PIO 1
101.6 × 53.3 mm24 parts4LCC-BY-NC-4.08
68000 PIO BOARD
101.6 × 53.3 mm23 parts4LCC-BY-NC-4.08
RC208-68000 BOOTROM RAM 2
101.6 × 53.3 mm20 parts4LCC-BY-NC-4.08
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