SWTPC was not the only vendor of SS30 and SS50 boards.

Smoke Signal Broadcasting M-16A Memory Board

Digital Research Corp. 16K RAM

DS68 Video Display

Micro Works 2708 Programmer

Southeastern Micro Systems DDC-16 FDC

Digital Research / Tanner 64K Memory Board

Seals Electronics 8k Memory Board

Homebrew 32K Static RAM

PERCOM SBC/9 Single Board Computer

Boaz Dymanic Memory board

Quality Research ACIA Interface

Quality Research SS-50 Proto Board

Quality Research PIA Interface

Quality Research Motherboard