DIGITAL COMPUTER ASSEMBLY

TM 11-6625-3081-23 1-10. DESCRIPTION OF ELECTRONIC STATION (cont) 1-10 k.2. DIGITAL COMPUTER ASSEMBLY 1A11 (1) Digital computer assembly 1A11 (Hewlett Packard HP1OOO A900) consists of a computer chassis assembly, CCAs Al thru A13, drawer slides, and jumper assembly ground lead. (2) Computer chassis assembly consists of a 20 slot card cage, power supply, fan panel, line filter, battery tray, and rear control panel. All CCAs are accessed by removing the rear panel. Each CCA slot is placarded from Al thru A20. Inside the card cage is a backplane which contains an electrical interface for CCAS and electronic components located in the front section of the computer chassis assembly. The rear control panel contains an ac power connector, power switch, test point connector, and ENABLE/DISABLE battery power switch. The backup power source (which includes the battery tray) is not provided for this configuration. A 115 vac input power line filter is located in the front section adjacent to the power supply. The power supply is a two tier CCA positioned on card guides and plugged into the backplane connector. The fan panel containing four fans is located behind the front panel . A multi-connector cable assembly connects the power supply to each of four fans. Air flow is from front to rear at approximately 120 CFM per fan. The louvered front panel contains a washable filter element. (3) Digital computer assembly 1A11 contains 13 CCAs as follows: 1A11A1 Control Store 1A11A2 Sequencer 1A11A3 Data Path 1A11A4 Cache Control 1A11A5 Memory Controller 1A11A6 Memory 1A11A7 HP-IB Interface 1A11A8 Asynchronous Serial Interface 1A11A9 IEEE Interface 1A11A1O Priority Jumper 1A11A11 HP-IB Interface 1A11A12 Parallel Interface 1A11A13 Buffer Change 6 1-26.1/(1-26.2 blank) (1-26.3 and 1-26.4 deleted)