Abstract: Memory modules are tested using a test assembly with a personal computer (PC) motherboard. The motherboard is mounted upside-down with its solder-side up to a metal plate using standoffs. A memory-module socket on the motherboard is removed. An opening is made in the metal plate above the removed socket. A well is attached to the metal plate at the opening. The well supports a test adaptor board below the metal plate so that the test adaptor board has a closer spacing to the motherboard than does the metal plate. The test adaptor board has a test socket that receives a module being tested. Pins from the test adaptor board are plugged into the holes of the removed socket on the motherboard, but mounted on the reverse, solder side of the motherboard rather than the component side. The cables, components, and expansion boards of the motherboards are hidden below the metal plate and motherboard, and can be cooled without cooling the memory module in the test socket.

Abstract: A distributed-object software application is capable of recovering from a server crash. The recovery is transparent to the client objects because the client objects do not have to be re-started or re-loaded. Proxies on the client machine handle the details of communication over the network with server objects. An intelligent proxy detects a server crash when no response is received from the server object. The intelligent proxy then sends a name identifier of the server object to a locator. The locator looks up the name identifier and returns a remote reference to another running instance of the server object. If no other running instance exists, the locator loads the server object onto another server machine. The intelligent proxy uses the remote reference from the locator to establish a connection with the new server machine and a session with the new server object. The intelligent proxy stored the last state of the server object before the crash.

Abstract: A processor module has a cache of SRAM chips mounted on both a back and a front surface but de-coupling capacitors mounted on only the back surface. Each de-coupling capacitor is for suppressing current spikes from a pair of SRAM chips. The pair of SRAM chips includes a first SRAM chip on the same surface as the capacitor and a second SRAM chip opposite the first SRAM chip on the front surface of the module. The first SRAM chip belongs to a first bank while the second SRAM chip belongs to a second bank. Two chip-enable signals control access to the two banks. Since only one bank is accessed at any time, and access causes current spikes, only one bank and only one SRAM chip in the pair of SRAM chips creates a current spike at any time. Thus, a capacitor can be shared between the two SRAM chips in the pair. The shared capacitor can be mounted next to or under one of the SRAM chips, or formed within the multi-layer substrate itself.

Abstract: A twisted-pair current driver is implemented in CMOS. EMI from sharp changes in the current driven is reduced by gradually changing the current driven when the inputs change. The current driver is divided into N differential drivers, each driving one-Nth of the total switching current to the twisted pair. Delay lines delay when input changes are sent to each of the four differential drivers, staggering their response. Either binary or multi-level-transition (MLT-3) data can be transmitted. A binary-to-MLT converter uses a dummy flip-flop to match delays and eliminate encoding glitches. Either the binary or the MLT-3 encoded data is coupled to the inputs of the delay lines and the differential drivers. The mid-level for MLT-3 is driven when both the inputs are high, causing the differential drivers to split the current among the two differential outputs to the twisted pair.