XassettsAsterisk is a DIY openhardware board for D1s

Git(hub) repository:
https://github.com/SdtElectronics/Xassette-Asterisk

BBS thread:
https://bbs.aw-ol.com/topic/489/网友-sdtee-分享的-d1s-开源原理图与-pcb-验证ok

Kicad files 1634386718975-xassetteasterisk.zip from:
https://bbs.aw-ol.com/assets/uploads/files/1634386718975-xassetteasterisk.zip

See also:

Hackaday project:
https://hackaday.io/project/182389-the-cheapest-risc-v-64-computer-by-now

J-L Aufranc from CNX-Software process to build some samples:
https://www.cnx-software.com/2021/12/24/manufacturing-xassette-asterisk-open-source-hardware-board/