4 layers82.8 × 62.8 mm
Tfr911h
strickyak/tfr9
The TFR/9 Single Board Computer for Hitachi 6309E or Motorola 6809E CPUs (TFR/901)
116 parts12MIT
4 layers97.6 × 96 mm
Centipede-32e
strickyak/copico-centipede7A Radio Shack / Tandy Color Computer ("Coco") wildcard peripheral cartridge, with an RP2350 processor and 46 usable GPIO lines, covering most of the Coco's expansion port bus.
- Size
- 97.6 × 96 mm
- Copper layers
- 4
- Thickness
- 1.6 mm
- Parts
- 135
- Nets
- 97
- Pads
- 471
- Tracks, vias
- 1,295, 155
- Pours
- 128
- Routed
- Yes
- KiCad
- KiCad 9.0 (file 20241229)
- Created
- 16 Mar 2026
- Updated
- 6 Sep 2026
Overview
Centipede-32e is an open-source printed circuit board by strickyak, from the strickyak/copico-centipede repository on GitHub, published under the MIT licence. It is a 4-layer board of 97.6 × 96 mm with 135 parts on 97 nets, routed with 1,295 tracks and 155 vias.
It is built around the 74HC14, HC-1.0-3PWT and K2-1808SN-A4SW-01, with the RCLAMP0521P.TCT-MS among its other parts. Its parts include 30 capacitors, 13 resistors, 8 diodes, 5 ICs and 5 connectors. It belongs with the radio and wireless boards of this library.
Main components
4
74HC14
SOP-14-40℃~+85℃ 1.9V、3.98V、4.4V、5.48V、5.9V 100mV、260mV、260mV 20uA 25ns@4.5V,50pF 2V~6V 6 74HC Noise suppression function Schmitt trigger SOP-14 Inverters ROHSJSMSEMIInverters
HC-1.0-3PWT
SMD,P=1mm,卧贴-25℃~+85℃ 1 1A 1mm 1x3P 3 3.2mm 3P 5.05mm 5.3mm 50V Auxiliary Solder Pin LCP Phosphor bronze SH Surface Mount, Right Angle Tin UL94V-0 SMD,P=1mm,Surface Mount，Right Angle Wire To Board Connector ROHSHCTLWire To Board Connector
K2-1808SN-A4SW-01
SMD,4.2x3.3mm-25℃~+85℃ 100,000 cycles 12V 2.5N 2.5mm 3.25mm 4.2mm 50mA Oval Button SPST Surface Mount,Vertical SMD,4.2x3.3mm Tactile Switches ROHSHRO ElectronicsTactile Switches
RCLAMP0521P.TCT-MS
04020.25pF 100W@8/20us 100nA 25V 4A 5V 6V Bidirectional IEC 61000-4-2、IEC 61000-4-5、IEC 61000-4-4 TVS 0402 ESD and Surge Protection (TVS/ESD) ROHSMSKSEMIESD And Surge Protection (TVS/ESD)
README
centipede-32e/README.mdCentipede 32d
TO DO -- document better.
This is pretty much a RP2350B microcontroller with direct connections to the Radio Shack Color Computer's 40-pin expansion bus.
The RP2350B may be powered either by the USB-C or by the Coco. The USB-C takes precedence by going through only one diode to VBUS, whereas the Coco's +5V input goes through two diodes.
Jumper J6 must be configured in one of two ways:
-
Preferred: Connect pins 2 and 3, and connect pins 4 and 5. This runs both E and Q through the schmidt trigger inverter to clean them. They arrive negated at GPIO 21 and 22.
-
Original: Connect pins 1 and 2, and pins 5 and 6. This runs E and Q direct to GPIO 21 and 22, not negated. This has problems with bouncy detection.
Maybe a BUG? VBUS powers the 74HC14.
Bug: CTS
On a coco3, we must obey CTS, not just the address range $C000-$DFFF.
Temporarily I'm bodging it from J5 to J4, CTS (negative logic) to GPIO18.
Clock Speed
My current PIO-less firmware works with the semi-fast poke ($FFD7) but not with the fast poke ($FFD9). That's with disk11.asm for Disk Basic Cart ROM, and a floppy at $FF40/$FF4[89AB].
Testing on a 16K Coco2 (named "2C") and a Coco3 with a 6309 and 512K RAM (named "3B").
Parts
135| Qty | Value | Footprint | References |
|---|---|---|---|
| 60 | Castellated Pad | My Stuff:Castellated Pad | 3V3_EN1, 3V31, ADC_VREF1, GND1, GND2, GND3, GND4, GND4, GND6, GPI10, GPIO0, GPIO1, GPIO1, GPIO1, GPIO1, GPIO1 +44 |
| 12 | 100nF | PCM_JLCPCB:C_0402 | C1, C2, C3, C4, C5, C6, C7, C8, C13, C14, C16, C36 |
| 5 | ~ | RP2350 Dev Board:POWERDI-123_L2.8-W1.8-LS3.7-RD | D1, D4, D5, D6, D7 |
| 4 | 100nF | PCM_JLCPCB:C_0603 | C9, C15, C38, C39 |
| 3 | 100nF | Capacitor_SMD:C_0603_1608Metric | C21, C23, C25 |
| 3 | 10uF | Capacitor_SMD:C_0603_1608Metric | C20, C22, C24 |
| 3 | 2kΩ | Resistor_SMD:R_0402_1005Metric | R9, R10, R12 |
| 3 | 33Ω | Resistor_SMD:R_0402_1005Metric | R2, R3, R6 |
| 2 | 10uF | PCM_JLCPCB:C_0603 | C37, C40 |
| 2 | 15pF | PCM_JLCPCB:C_0402 | C17, C18 |
| 2 | 4.7uF | PCM_JLCPCB:C_0603 | C10, C12 |
| 2 | 4.7uF | PCM_JLCPCB:C_0402 | C11, C19 |
| 2 | 5.1kΩ | Resistor_SMD:R_0402_1005Metric | R1, R4 |
| 2 | Conn_02x03_Odd_Even | Connector_PinHeader_2.54mm:PinHeader_2x03_P2.54mm_Vertical_SMD | J5, J6 |
| 2 | K2-1808SN-A4SW-01 | RP2350 Dev Board:KEY-SMD_4P-L4.2-W3.2-P2.20-LS5.1-TL | Boot1, Reset1 |
| 2 | RCLAMP0521P.TCT-MS | EasyEDA:D0402-BI | D2, D3 |
| 2 | SolderJumper_2_Bridged | Jumper:SolderJumper-2_P1.3mm_Bridged_Pad1.0x1.5mm | JP1, JP2 |
| 1 | 100kΩ | Resistor_SMD:R_0402_1005Metric | R11 |
| 1 | 1kΩ | PCM_JLCPCB:R_0603 | R28 |
| 1 | 1kΩ | Resistor_SMD:R_0402_1005Metric | R5 |
| 1 | 1Ω | PCM_JLCPCB:R_0603 | R7 |
| 1 | 200Ω | PCM_JLCPCB:R_0603 | R8 |
| 1 | 74HC14 | Package_SO:SOIC-14_3.9x8.7mm_P1.27mm | U5 |
| 1 | CocoEdgeConnector | 0Titanium:CocoCardEdgeCocoMIDI | P1 |
| 1 | Conn_02x10_Odd_Even | Connector_PinHeader_2.54mm:PinHeader_2x10_P2.54mm_Vertical | J4 |
| 1 | Conn_02x10_Odd_Even | Connector_PinSocket_2.54mm:PinSocket_2x10_P2.54mm_Vertical_SMD | J3 |
| 1 | HC-1.0-3PWT | EasyEDA:CONN-SMD_SM03B-SRSS-TB-LF-SN-P | U2 |
| 1 | Red | LED_SMD:LED_0603_1608Metric | LED25 |
| 1 | Red | PCM_JLCPCB:D_0603 | PWR_LED1 |
| 1 | W25Q128 | PCM_JLCPCB:SOIC-8_L5.3-W5.3-P1.27-LS8.0-BL | U4 |
| 1 | ~ | PCM_JLCPCB:SOT-23-5_L3.0-W1.7-P0.95-LS2.8-BR | U3 |
| 1 | ~ | RP2350 Dev Board:IND-SMD_L2.0-W1.6_AOTA-B201610S3R3-101-T | L1 |
| 1 | ~ | RP2350 Dev Board:QFN-80_L10.0-W10.0-P0.40-TL-EP3.4 | U1 |
| 1 | ~ | RP2350 Dev Board:USB-C-SMD_TYPE-C-6PIN-2MD-073 | USB1 |
| 1 | ~ | RP2350 Dev Board:CRYSTAL-SMD_4P-L3.2-W2.5-BL | X1 |
The 129 most common of 135 parts.
Questions
How big is the Centipede-32e PCB?
It measures 97.6 × 96 mm and has 4 copper layers, 1.6 mm thick.
What parts does the Centipede-32e use?
135 parts, built around the 74HC14, HC-1.0-3PWT, K2-1808SN-A4SW-01 and RCLAMP0521P.TCT-MS. 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 Centipede-32e KiCad files?
From the strickyak/copico-centipede repository on GitHub, at the commit this page was made from: the board is centipede-32e/centipede-32e.kicad_pcb and its schematic centipede-32d/centipede-32d.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Centipede-32e design in my own project?
Its repository publishes it under the MIT licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).
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