Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!texbell!ficc!peter From: peter@ficc.ferranti.com (Peter da Silva) Newsgroups: comp.unix.i386 Subject: Direct screen writes (Re: Graphic characters in Norton Utilities SYS-V) Keywords: Norton Utilities, graphic characters Message-ID: Date: 3 Aug 90 16:00:28 GMT References: <1990Jul31.101937.9157@pcrat.uucp> <8Y-48O9@xds13.ferranti.com> <1990Aug3.002317.12535@pcrat.uucp> Reply-To: peter@ficc.ferranti.com (Peter da Silva) Organization: Xenix Support, FICC Lines: 27 In article <1990Aug3.002317.12535@pcrat.uucp> rick@pcrat.UUCP (Rick Richardson) writes: > In some cases, it simply must be done. Anything that wants to do > graphics is going to have to go directly to the screen. That's a different matter, though a less CPU-expensive standard than X for using this resource would be desirable, I don't see one forthcoming. But where acceptable standards exist (termcap, terminfo) they must be used. > In other cases, direct screen writes are of tremendous value. > People find it convenient to lean on the arrow keys to move > around, and expect to stop on a dime when they see where they > want to be. There are many programs that provide this facility over even slow serial ports, by either doing heuristics to determine when to do updates, or by simply abandoning the current update of the screen image so long as input is pending. Another point to consider is that this sort of interaction is, while simple to understand and implement, not always the most convenient for the average user. The time spent making this fast could have been better spent implementing more powerful tools such as incremental searches. Optimisation is not free. Gratuitous optimisation can be translated directly into missing features or later release dates. I consider optimising a program for the special case of users logged in directly at the console, and not using X, to be gratuitous. -- Peter da Silva. `-_-' +1 713 274 5180. 'U`