This section discusses the general I/O (input/output) statements of HTBasic. General I/O statements apply equally to screen, keyboard, printer, files, interfaces, devices, strings, and buffers. The sections following this one discuss these I/O destinations/sources in greater detail. You should read the information in this section first, and then read any of the following sections you need. BEEP, READ, and DATA statements are also presented in this section.
There are two pairs of statements that are used in general I/O: ENTER/OUTPUT and STATUS/CONTROL. Some interfaces also support interrupts, which can be used to force program branching on different interface conditions. Some interfaces also support background transfers. The TRANSFER statement starts background transfers.
Associated with each I/O operation is an I/O path. An I/O path contains all of the routing information necessary for the computer to transfer data between your HTBasic program and the target entity (such as a printer, data acquisition device, string, file, etc.). The ASSIGN statement is used to set up an I/O path for use in later ENTER, OUTPUT, and TRANSFER statements.