Minimal-6502
About the Minimal-6502 PCB
Minimal-6502 is an open source PCB design by techav-homebrew, published on GitHub. It is a 2-layer board measuring 101.6 × 76.2 mm, with 30 components from 20 distinct parts.
Other key parts include the MC68B50, MAX232, 74LS00, 74LS04 and CY62256. By type, the board carries 8 ICs, 8 resistors, 7 capacitors, 5 connectors, 1 crystal and 1 switch.
It belongs with the retro computing and usb & debug tools designs in this gallery.
From the project
Minimal 6502 SBC based on Grant Searle's 8-chip 6502 computer
Modifications from Grant Searle's design include: - Addition of expansion header - Changed clock from crystal to standard TTL can oscillator - Added option for USB for serial & power via FTDI - Reassembled software for 8kB EEPROM instead of 16kB EPROM because 27128 EPROM is not readily available (PCB still supports 27128)
Computer can be assembled with either an RS-232 serial port for use with a traditional terminal or USB serial adapter for use with a modern computer as a terminal. Parts related to each option are listed below.
Main components on the Minimal-6502
Minimal-6502 bill of materials (BOM)
30 components, 20 distinct parts.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | MC68B50 | DIP-24_W15.24mm_Socket | U1 |
| 1 | MAX232 | DIP-16_W7.62mm_Socket | U2 |
| 1 | 74LS00 | DIP-14_W7.62mm_Socket | U3 |
| 1 | 74LS04 | DIP-14_W7.62mm_Socket | U4 |
| 1 | CY62256 | DIP-28_W15.24mm_Socket | U5 |
| 1 | 27128 | DIP-28_W15.24mm_Socket | U6 |
| 1 | R6502 | DIP-40_W15.24mm_Socket | U7 |
| 1 | FT230XS | SSOP-16_3.9x4.9mm_P0.635mm | U8 |
| 1 | 1.8432MHz | Oscillator_DIP-8 | X1 |
| 1 | DE9_Plug | DSUB-9_Male_EdgeMount_P2.77mm | J1 |
| 1 | USB_B | USB_B_OST_USB-B1HSxx_Horizontal | J2 |
| 1 | Barrel_Jack_Switch | BarrelJack_Horizontal | J3 |
| 1 | Conn_02x20_Odd_Even | PinHeader_2x20_P2.54mm_Horizontal | J4 |
| 1 | Conn_01x14 | PinHeader_1x14_P2.54mm_Vertical | J5 |
| 1 | SW_Push | SW_PUSH_6mm | SW1 |
| 5 | 1uF | C_Disc_D5.0mm_W2.5mm_P2.50mm | C1, C2, C3, C4, C5 |
| 1 | 10uF | CP_Radial_D8.0mm_P5.00mm | C6 |
| 1 | 100nF | C_Disc_D5.0mm_W2.5mm_P2.50mm | C7 |
| 6 | 2K2 | R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R1, R2, R5, R6, R7, R8 |
| 2 | 27R | R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R3, R4 |
Minimal-6502 design files
The KiCad project lives in the techav-homebrew/Minimal-6502 repository on GitHub; these links point at the commit this page was built from.
- LayoutPCB/Minimal-6502.kicad_pcb
- SchematicPCB/Minimal-6502.kicad_sch
Minimal-6502: common questions
How big is the Minimal-6502 PCB?
The Minimal-6502 measures 101.6 × 76.2 mm, has 2 copper layers and is 1.6 mm thick.
How many components are on the Minimal-6502?
30 components, from 20 distinct parts. The full bill of materials is listed on this page.
Where can I download the Minimal-6502 design files?
From the techav-homebrew/Minimal-6502 repository on GitHub, which has the KiCad layout and the schematic; the links under Design files point to each one.
Can I use the Minimal-6502 design in my own project?
The repository has no license, so all rights stay with techav-homebrew. Use it as a reference, and ask the author before reusing the design.
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