One power supply units (PSU) are included in this artifact description. other appears to be manufactured by Teletype Corporation. Main system unit (Xitan) contains the following PCBs: 1. S-100 Backplane 2. "ZPU" Z80 CPU 3. "Expandoram" 8 x 4 x 4164 DRAM (likely 4K size) 4. "Versafloppy" FDD Controller 5. "Versafloppy II" FDD/HDD Controller 6. "SMB II" Serial Interface Board (kluge to baud rate controller box).
