Star Micronics SB-15 user manual For IBM mode

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Our chart would hardly be complete with just a picture of a chemist’s flask, so in Figure 9-9 we’ve made completed grids for some other symbols: an automobile and a gun (quite a strange mix of characters!). The information on the grids is now complete (except for proportional width data-a more advanced topic we’ll take up shortly).

nDownload character definition command

You’ve read through a long explanation of download characters and we haven’t even told you the command syntax yet! Now the wait is over. This is the most complex command in the SD-lo/15 repertoire and now you’ve got the necessary knowledge to im- plement it. Here it is:

(For STAR mode)

<ESC> "~~" 1 nl n2 rn@ ml m2 m3 m4 m5 m6 m7 m8

m9 ml@ ml1

(For IBM mode)

<ESC> "6" CHR$(Q))nl n2 rng ml m2 m3 m4 m5 m6

m7 m8 m9 ml0 ml1

Like the other SD-lo/l5 commands, it starts with an < ESC > (CHR$(27)). The next character is an asterisk (*) (CHR$(42)) followed by 1, or an ampersand (6~) (CHR$(38)) followed by a CHR$(O).

nl and n2 are used to specify the ASCII values of the characters you are defining. The reason that there are two bytes reserved for this is that SD-lo/l 5 allows you to define many characters with just a single command. nl is used to specify the beginning of a range of characters to be defined; n2 specifies the end of the range. For instance, if you wanted to change the appearance of the numerals from 0 to 9 (which have ASCII codes 48 through

57)for the STAR mode, the command would begin with < ESC > ‘I*” CHR$(l) CHR$(48) CHR$(57)... Of course, you can also define individual characters by making nl and n2 equal.

mCJis called the attribute byte, for it describes two attributes of the character we have designed: descender data and propor- tional width information. A byte consists of eigth bits. In the attribute byte, the first (high order) bit is used for the descender data, and the last seven bits are used for proportional widths.

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