From: utzoo!decvax!ucbvax!C70:bitgraph Newsgroups: fa.bitgraph Title: Re: Bugs in Firmware Article-I.D.: ucb.1531 Posted: Fri Jul 16 14:30:04 1982 Received: Sat Jul 17 02:31:28 1982 >From edmond@BBN-UNIX Fri Jul 16 14:29:34 1982 Probably the reason for the gray rectangle is the use of DEL characters for padding functions like Insert and Delete Line. The BitGraph displays DELs as a box, where the H19 and the VT52 discard DELs. The TOPS-20 EMACS likes to use DEL characters for padding. Other TOPS-20 and TENEX programs also prefer DEL to NUL, since NUL is often used as a string terminator by operting system functions. -WBE