MC68000
About the MC68000 PCB
MC68000 is an open source PCB design by bobofet2-1, published on GitHub. It is a 2-layer board measuring 432.5 × 139 mm, with 59 components from 35 distinct parts.
Other key parts include the MC68681P, 68000D, LM555xN, 74LS373 and 74LS245. By type, the board carries 25 ICs, 16 resistors, 10 capacitors, 3 connectors, 2 crystals and 1 switch.
From the project
Code and design of legacy MC68000 proto board
This is an isolated KiCad project copy created from hardware\MC68000 for the address-decoder redesign. The original project has not been modified.
The reviewed decoder specification is in:
- 128 KiB RAM at 0x000000-0x01FFFF; - the 64 KiB U15/U16 ROM pair at 0xFF0000-0xFFFFFF; - a reset-set ROM alias for 0x000000-0x000007; and - an /AS-clocked, one-way overlay release after the vector word at 0x000006.
Main components on the MC68000
MC68000 bill of materials (BOM)
59 components, 35 distinct parts.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | MC68681P | DIP-40_W15.24mm | IC1 |
| 1 | 68000D | DIP-64_W22.86mm | U1 |
| 1 | LM555xN | DIP-8_W7.62mm | U2 |
| 3 | 74LS373 | DIP-20_W7.62mm | U3, U4, U5 |
| 2 | 74LS245 | DIP-20_W7.62mm | U6, U7 |
| 2 | 74LS32 | DIP-14_W7.62mm | U8, U17 |
| 2 | 74LS04 | DIP-14_W7.62mm | U9, U10 |
| 2 | 74LS138 | DIP-16_W7.62mm | U11, U29 |
| 2 | 628128_DIP32_SSOP32 | DIP-32_W15.24mm | U12, U20 |
| 3 | 74LS00 | DIP-14_W7.62mm | U13, U25, U26 |
| 1 | 74LS08 | DIP-14_W7.62mm | U14 |
| 2 | 28C256 | DIP-28_W15.24mm | U15, U16 |
| 1 | EW20200YMY | PinHeader_2x08_P2.54mm_Vertical | U19 |
| 1 | 74LS05 | DIP-14_W7.62mm | U22 |
| 1 | DS12887 | DIP-24_W15.24mm | U31 |
| 1 | 16MHz | Crystal_HC49-U_Horizontal | Y1 |
| 1 | 3.6864 MHz | Crystal_HC49-U_Horizontal | Y2 |
| 1 | Conn_Coaxial_Power | BarrelJack_CUI_PJ-102AH_Horizontal | J1 |
| 1 | FT232RL board | PinHeader_1x06_P2.54mm_Vertical | J2 |
| 1 | DUART_OP_PORT | PinHeader_2x10_P2.54mm_Vertical | J3 |
Show 15 more
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | 10K | Potentiometer_Bourns_3296W_Vertical | RV1 |
| 1 | reset | SW_PUSH_6mm | SW1 |
| 1 | LED | LED_0201_0603Metric_Pad0.64x0.40mm_HandSolder | D1 |
| 1 | 10nF | C_Disc_D3.0mm_W2.0mm_P2.50mm | C1 |
| 1 | 100n | C_Disc_D3.0mm_W2.0mm_P2.50mm | C2 |
| 1 | 10n | C_Disc_D3.0mm_W2.0mm_P2.50mm | C3 |
| 1 | 1u | C_Disc_D3.0mm_W2.0mm_P2.50mm | C4 |
| 4 | 15p | C_Disc_D3.0mm_W2.0mm_P2.50mm | C5, C6, C7, C8 |
| 1 | 10uF | C_Disc_D3.0mm_W2.0mm_P2.50mm | C9 |
| 1 | 100nF | C_Disc_D3.0mm_W2.0mm_P2.50mm | C10 |
| 3 | 1M | R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R1, R7, R9 |
| 9 | 4.7K | R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R2, R3, R4, R10, R11, R12, R13, R14 +1 |
| 2 | 470 | R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R5, R8 |
| 1 | 220 | R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R6 |
| 1 | 10K | R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R16 |
MC68000 design files
The KiCad project lives in the bobofet2-1/mc68k-proto-board repository on GitHub; these links point at the commit this page was built from.
MC68000: common questions
How big is the MC68000 PCB?
The MC68000 measures 432.5 × 139 mm, has 2 copper layers and is 1.6 mm thick.
How many components are on the MC68000?
59 components, from 35 distinct parts. The full bill of materials is listed on this page.
Where can I download the MC68000 design files?
From the bobofet2-1/mc68k-proto-board repository on GitHub, which has the KiCad layout and the schematic; the links under Design files point to each one.
Can I use the MC68000 design in my own project?
The repository has no license, so all rights stay with bobofet2-1. Use it as a reference, and ask the author before reusing the design.
