The DDC BUS-65515 is a full-size IBM PC interface card that implements MIL-STD-1553B data bus connectivity for legacy computer systems. Operating as a Bus Controller (BC), Remote Terminal Unit (RTU), or Monitor Terminal (MT)—selectable via software—this module enables integration of dual-redundant 1553 avionics networks into PC-based architectures. The card features 4K × 16 dual-access RAM with double-buffered architecture to prevent data corruption during reads and writes. Onboard time-tag counter and dynamic wrap-around Built-In Test (BIT) capability support comprehensive system diagnostics. Interrupt level and RTU address are jumper-programmable; software control extends to RTU address and data block allocation. The module couples directly or via transformer to external MIL-STD-1553 buses and operates under PC DOS 3.0 or higher on any IBM PC-compatible system with an available ISA slot.
## Technical Specifications
• **Interface:** IBM PC Bus (ISA)
• **Standard Compliance:** MIL-STD-1553B, full compliance including dual-redundant message formats and mode codes
• **Functional Modes:** Bus Controller, Remote Terminal Unit, Monitor Terminal (software selectable)
• **Memory:** 4K × 16 dual-access RAM with double-buffering
• **Time Tagging:** Onboard Time Tag Counter
• **Built-In Test:** Dynamic wrap-around BIT
• **Configuration:** Jumper-programmable interrupt level and RTU address; software-programmable RTU address and data block allocations
• **Bus Coupling:** Direct or transformer-coupled to MIL-STD-1553 bus
## Key Features
• Dual-access memory architecture ensures data integrity against partial reads and transmissions
• Single-card integration eliminates external chassis or standalone interfaces
• Selectable operational modes address BC, RTU, and MT requirements without hardware changes
• Onboard time-tag counter provides precise message sequencing for protocol compliance
## Typical Applications
• Legacy avionics data acquisition and telemetry systems
• MIL-STD-1553 bus emulation and protocol testing
• Retrofit integration of 1553 networks into existing PC platforms
## Compatibility & Integration
• **Host System:** IBM PC or compatible with ISA slot available
• **Operating System:** PC DOS 3.0 or higher
• **Interface Signals:** I/O Check, Data Bits (D0–D7), I/O Ready, Address Enable, Address Bits (A12–A19)
