Define download characters
Mode ASCII |
|
| Decimal | Hexadecimal | ||||
<ESC> “=” | nl n2 | “#” | 27 | 61 nl | n2 35 IB 3D nl | nl | 23 | |
n3 n4 | <O> | n5 | & | n4 | O ti | n3 n4 | 00 n.5 | |
IBM | m2 | m9 |
| ml m2 | ... m9 | ml m2 . . m9 | ||
ml |
| |||||||
dl | d2 ““ | ... (ix |
| dl d2 ... | dl | d2 . | dx |
Definesnew charactersand storesthemin RAMfor lateruse. EDS
DownloadingcharactersinIBMmoderequiresDotPatterndataand CharacterIndex Table data. Dot Pattern data controlswhich pins fire when printing a character. Index Table data is placed in a “lookuptable”thatprovidesinformationon whereDotPatterndata is storedin memoryand definescertainattributesof the character.
(d + n2 x 256) give the numberof bytesto be downloaded.
n3 and n4 indicatethe loworderandhighorderaddressesin which data is to be stored.n3 shouldbe 15 and n4 shouldbe 128for this printer.
ti determinesthe charactermode to be downloaded,as shown below:
rL5 | Charactermode | Characterwidth |
o | Draft | 9 |
1 | LQpica | 35 |
2 | LQproportional | |
3 | LQelite | 29 |
ml throughm9 indicateIndexTable data.
ml andm2indicatethe adresswhereDotPatternis stored.ml is the
ti through m9 are compressionmask bits. Data compression allowsthe efficientuse of memoryin storingdownloadedcharac- ters providingspace for more charactersthan would be available withoutcompression.The printerrepeatsthe previousdot column in the currentcolumnwhenthe currentcolumncompressionmask bit is set to 1.
Itisnecessaryto defineallofIndexTabledatabeforetheDotPattern data to downloadmany characters.
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