CORTELCO ARIES DIGITAL KEY SYSTEM PBX PHONE SYS. ADKS-144COMM BOARD $99 Here is some info I found on the internet. I cannot be positive it it is all true to this system. We are not experts. All eight cabinets are identical and in excellent working condition. We also have 150 + phones that came with this syustem that we are selling seperately! Make us a deal on all of it! The Aries Digital 144 Key System offers nine universal PBA slots and one T-1 slot. ( I don't think these have the T-1 card??) The system can be configured using digital station, analog station or analog trunk PBAs. A serial interface is offered for CTI applications via an RS-232 connection and Caller ID. The system circuitry and power supply are contained in a metal cabinet that can be desk or wall-mounted. Lines and stations are connected via amphenol connectors located inside the cabinet. Connections for other optional equipment are also located inside the cabinet. Telephones include the Executive 28-button, the Standard 16-Button and the low-cost Basic model. The telephones connect to the KSU via a single-pair of wires. Programming the system can be performed using an executive telephone or personal computer. P.C. programming can be done while not attached to the system. Optional features supported by the system are external music, external paging and a relay connection for ringer volume control. The system provides circuitry to support a backup battery package.