OpenSpand
About the OpenSpand PCB
OpenSpand is an open source PCB design by paulczy, published on GitHub. It is a 4-layer board measuring 100 × 76.1 mm, with 28 components from 26 distinct parts.
Other key parts include the mcp23009-E/p and PICO2XL. By type, the board carries 7 connectors, 5 capacitors, 5 resistors, 3 ICs, 3 diodes and 2 switches.
From the project
The OpenSpand is an all-in-one expansion solution for Sinclair ZX81 computers and clones. Functionally very similar to ZXpand+, with more and extended functions.
The OpenSpand is an all-in-one expansion solution for Sinclair ZX81 computers and clones. Functionally very similar to ZXpand+, with more and extended functions.
Since the hardware design and software are open source, everything can be changed and expanded by others, making this a future proof ZX81 expansion. It is relatively cheap and easy to build. Others will hopefully find it easy to expand the functionality.
Main components on the OpenSpand
OpenSpand bill of materials (BOM)
28 components, 26 distinct parts — part numbers from the project's BOM.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | ~ | DS1307Module_BatteryUP | U1 |
| 1 | mcp23009-E/p MCP23009-E_P | DIP-18_W7.62mm | U2 |
| 1 | PICO2XL Pico2XL | P2350Pico2XL | U3 |
| 1 | 5VPIN7 | PinHeader_1x02_P2.54mm_Vertical | J1 |
| 1 | External SPI | PinHeader_2x03_P2.54mm_Horizontal | J2 |
| 1 | DigitizedAudio | PinHeader_1x04_P2.54mm_Horizontal | J4 |
| 1 | I2C_AND_UART I2C_and_UART | PinHeader_2x04_P2.54mm_Horizontal | J5 |
| 1 | 5VPIN5 | PinHeader_1x02_P2.54mm_Vertical | J6 |
| 1 | VIDEO75 Video75 | PinHeader_1x02_P2.54mm_Vertical | J7 |
| 1 | CONN_01X15_PIN Conn_01x15_Pin | UDA1334 | J8 |
| 1 | ~ | ZX-EDGE64-2 | 0 |
| 1 | SD-5-B | SD_TE_2041021 | SDCard0 |
| 1 | Config | SW_Tactile_SPST_Angled_PTS645Vx83-2LFS | SW0 |
| 1 | Reset | SW_Tactile_SPST_Angled_PTS645Vx83-2LFS | SW1 |
| 1 | Conn_01x02 | ZX Video1 | VideoConnector1 |
| 1 | GREEN | LED_D5.0mm | D0 |
| 1 | RED | LED_D5.0mm | D1 |
| 1 | 1N5817 | D_DO-41_SOD81_P10.16mm_Horizontal | D2 |
| 1 | 10V 10uF | C_1210_3225Metric_Pad1.33x2.70mm_HandSolder | C1 |
| 2 | 100N 100n | C_Disc_D3.0mm_W1.6mm_P2.50mm | C2, C3 |
Show 6 more
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | 16V 47uF | C_1210_3225Metric_Pad1.33x2.70mm_HandSolder | C4 |
| 1 | 10V 1uF | C_1210_3225Metric_Pad1.33x2.70mm_HandSolder | C5 |
| 2 | 1k | R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R1, R2 |
| 1 | 75R | R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R3 |
| 1 | 270R | R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R4 |
| 1 | 470R | R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R5 |
OpenSpand design files
The KiCad project lives in the paulczy/OpenSpand repository on GitHub; these links point at the commit this page was built from.
OpenSpand: common questions
How big is the OpenSpand PCB?
The OpenSpand measures 100 × 76.1 mm, has 4 copper layers and is 1.6 mm thick.
How many components are on the OpenSpand?
28 components, from 26 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 OpenSpand design files?
From the paulczy/OpenSpand 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 OpenSpand design in my own project?
The repository has no license, so all rights stay with paulczy. Use it as a reference, and ask the author before reusing the design.