X-Acto knife

(ex act toe) N. A small, razor-sharp knife with a disposable blade used (in electronics) to remove solder bridges between IC pins, clean up PCB tracks, and trim fingernails. The X-Acto knife is part of the universal troubleshooting kit needed by every developer. Other components include duct tape, 10-kΩ resistors, and Super Glue.

The indispensible X-Acto knife, with the usual hint of blood on its tip

x86

(ex eighty-six) abbr. See 80x86.

Xilinx

(zy links) N. The world's leading provider of programmable logic devices, with 50% of the market in 2002. Founded in 1984, Xilinx pioneered the FPGA and now also sells a line of CPLDs. Listed by Fortune Magazine in 2001 and 2002 as one of the best 100 companies to work for.

XOFF

(ex off) n. A special character transmitted in-band to request a resumption of a previously paused flow of incoming data. ASCII 0x13. See also XON, software flow control.

XON

(ex or) n. A special character transmitted in-band to request a pause in the flow of incoming data. ASCII 0x11.

Note that because the XON character is sent in the communications channel, binary data sent across the channel must be stripped of all 0x11s. This is typically done by inserting an escape code before the binary data's 0x11 is sent so that the device on the other end will know not to interpret that next byte as an XON. See also XOFF, software flow control.