2 layers157.5 × 180.3 mm
BenEater-6502
wnoisephx/BenEater-6502
A KiCad PCB layout for Ben Eater's 6502 computer with some minor updates and an expanded I/O
115 parts
2 layers221 × 179 mm
Sun6502
Aktr0s/Sun65021My 6502 Hobby Computer
- Size
- 221 × 179 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 53
- Nets
- 196
- Pads
- 517
- Tracks, vias
- 1,493, 124
- Pours
- 2
- Routed
- Yes
- KiCad
- KiCad 9.0 (file 20241229)
- Created
- 27 May 2025
- Updated
- 10 Jun 2026
Overview
Sun6502 is an open-source printed circuit board by Aktr0s, from the Aktr0s/Sun6502 repository on GitHub. It is a 2-layer board of 221 × 179 mm with 53 parts on 196 nets, routed with 1,493 tracks and 124 vias.
It is built around the MAX232N, 74LS00SC and 74LS139PC, with the 74LS21PC and SB140 among its other parts. Its parts include 18 capacitors, 11 ICs, 6 resistors, 5 diodes and 4 connectors.
Main components
5
MAX232N
PDIP-160℃~+70℃ 120Kbps 2 2 4.5V~5.5V Transceiver PDIP-16 RS232 ICs ROHSTexas InstrumentsRS232 ICs
74LS00SC
-0℃~+70℃ 15ns@5V,50pF 2 2.7V 2V 4 4.75V~5.25V 400uA 500mV 74LS 800mV 8mA NAND Gate - Logic Gates ROHSTexas InstrumentsLogic Gates74LS139PC
PDIP-1622ns 74LS 8mA Decoder Single Supply PDIP-16 Signal Switches, Multiplexers, DecodersonsemiSignal Switches, Multiplexers, Decoders
74LS21PC
DIP-140℃~+70℃ 18ns@5V,50pF 2 2.7V~3.4V 2V 4 4.75V~5.25V 400uA 500mV 74LS 800mV 8mA AND Gate DIP-14 Logic Gates ROHSonsemiLogic Gates
SB140
DO-41-65℃~+125℃ 1 Independent 1A 30A 40V 500mV@1A 500uA@40V DO-41 Schottky Diodes ROHSonsemiSchottky Diodes
README
README.mdSun6502 Hobby Computer
My first try at electonics. Wish me luck.
Memory Map:
| Address Range | Size | Description |
|---|---|---|
$0000-$7FFF | 32KB | RAM |
$8000-$83FF | 1KB | VIA #1 |
$8400-$87FF | 1KB | UART |
$8800-$8BFF | 1KB | VIA #2 |
$8C00-$8FFF | 1KB | Unused |
$9000-$BFFF | 12KB | Expansion Port |
$C000-$FFFF | 16KB | ROM |
Total: 64KB
If you have a previous version of the board notice that UART and VIA #2 addresses are swaped around.
More Info:
While VIA's and UART have 1KB they only use first needed bits.
VIA#2 Port (Expansion) does not have CE/ signal but Bus Expansion Port does.
It should be compatible with Ben's Breadboard 6502 but you HAVE to change memory adressess since the memory map is different as well as elements connected to VIA
The project took inspiration from:
- Ben Eater Breadboard 6502 Computer
- PE6502 by Putnam Electronics
[!NOTE] This project has been tested and is confirmed to work.
[!CAUTION] Do NOT use 74LS series TTL chips. It messes up logic and memory. Use 74HC series CMOS chips! If somewhere on PCB or schematic there is a mention of TTL chips, ignore them and use CMOS chips!
Software:
Software for this computer is based on
Original README files are in "msbasic_for_sun6502" folder.
Parts
53| Qty | Value | Footprint | References |
|---|---|---|---|
| 11 | 100nf | Capacitor_THT:C_Disc_D5.0mm_W2.5mm_P5.00mm | C1, C2, C3, C4, C5, C6, C8, C9, C10, C11, C13 |
| 4 | 1uF | Capacitor_THT:C_Disc_D5.0mm_W2.5mm_P5.00mm | C14, C15, C16, C17 |
| 4 | SB140 | Diode_THT:D_DO-41_SOD81_P10.16mm_Horizontal | D1, D2, D3, D6 |
| 2 | 3.3k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P15.24mm_Horizontal | R2, R5 |
| 2 | 6-5530843-5 | footprints:TE_6-5530843-5 | J2, J3 |
| 2 | W65C22NxP | Package_DIP:DIP-40_W15.24mm_Socket_LongPads | U4, U7 |
| 1 | 1.8432Mhz | Crystal:Crystal_HC49-U_Vertical | Y2 |
| 1 | 100nf | Capacitor_THT:C_Disc_D4.7mm_W2.5mm_P5.00mm | C20 |
| 1 | 100uF | Capacitor_THT:CP_Radial_D6.3mm_P2.50mm | C7 |
| 1 | 1M | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P15.24mm_Horizontal | R4 |
| 1 | 1Mhz | Oscillator:Oscillator_DIP-14 | Y1 |
| 1 | 1k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P15.24mm_Horizontal | R1 |
| 1 | 20pf | Capacitor_THT:C_Disc_D5.0mm_W2.5mm_P5.00mm | C18 |
| 1 | 250 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R6 |
| 1 | 28C256 | Socket:DIP_Socket-28_W11.9_W12.7_W15.24_W17.78_W18.5_3M_228-1277-00-0602J | U3 |
| 1 | 500 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P15.24mm_Horizontal | R3 |
| 1 | 74LS00 | Package_DIP:DIP-14_W7.62mm_Socket_LongPads | U11 |
| 1 | 74LS138 | Package_DIP:DIP-16_W7.62mm_Socket_LongPads | U9 |
| 1 | 74LS139 | Package_DIP:DIP-16_W7.62mm_Socket_LongPads | U5 |
| 1 | 74LS21 | Package_DIP:DIP-14_W7.62mm_Socket_LongPads | U6 |
| 1 | Barrel_Jack_MountingPin | Connector_BarrelJack:BarrelJack_Horizontal | J1 |
| 1 | Buzzer | Buzzer_Beeper:Buzzer_TDK_PS1240P02BT_D12.2mm_H6.5mm | BZ1 |
| 1 | DE9_Socket | Connector_Dsub:DSUB-9_Socket_Horizontal_P2.77x2.84mm_EdgePinOffset7.70mm_Housed_MountingHolesOffset9.12mm | J4 |
| 1 | FerriteBead | Ferrite_THT:LairdTech_28C0236-0JW-10 | FB1 |
| 1 | KM62256CLP | Package_DIP:DIP-28_W15.24mm_Socket_LongPads | U2 |
| 1 | LED | LED_THT:LED_D5.0mm | D4 |
| 1 | LOGO | LOGO | G*** |
| 1 | MAX232 | Package_DIP:DIP-16_W7.62mm_Socket_LongPads | U10 |
| 1 | Power Switch | footprints:2MS6T1B3M2QES | SW2 |
| 1 | RESET | Button_Switch_THT:SW_PUSH_6mm_H5mm | SW1 |
| 1 | R_Potentiometer | Potentiometer_THT:Potentiometer_Alps_RK09K_Single_Vertical | RV1 |
| 1 | W65C02SxP | Package_DIP:DIP-40_W15.24mm_Socket_LongPads | U1 |
| 1 | W65C51NxP | Package_DIP:DIP-28_W15.24mm_Socket_LongPads | U8 |
| 1 | WC1602A | Display:WC1602A | DS1 |
Questions
How big is the Sun6502 PCB?
It measures 221 × 179 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Sun6502 use?
53 parts, built around the MAX232N, 74LS00SC, 74LS139PC and 74LS21PC. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the Sun6502 KiCad files?
From the Aktr0s/Sun6502 repository on GitHub, at the commit this page was made from: the board is SUN6502.kicad_pcb and its schematic SUN6502.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Sun6502 design in my own project?
Its repository states no licence, so its author keeps all rights: ask Aktr0s before reusing the design.
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