The Rainbow Vol. 09 No. 01 - August 1989 - TRS-80 Color ...

DESKTOPH and Epso n-compatible printers.
Your DESKTOPH program w ill have to be
altered to work w ith DRIVERHT or DRIV­
E RH E, by merging with it one of four patch
program s - HALTER, HAL TERD , HAL TERE ,
and HAL TERDE - of Listings 3, 4, 5 and 6,
res pective ly . W hich one of the patch programs
you mu st merge w ith DESKTOPH
depend s on what version of th at program
you are using. Prese ntly, there are effectively
four different ve rsions of DESKTOPH .
These different ve rsions are an outgrowth
of sel ling to m any tlESKTOPH use rs a builtin
sc reen dump, enhancements or both. The
four versions are as follows :
e V ersion I - The ori ginal DESKTOPH
w ith 2, I 0 or 19 fonts, w ith or w ithout the
word processor input feature introduced in
The Desktop Publisher: A Reprise (September
'88 iss ue of THE RA INBOW).
• V ersion 2 - L ike Version I with the
exception th at a patch program merged
with DESKTOPH gives the 0 command sc reen
clump capabi lities .
• Version3-Like V ersion l , but a patch
program merged w ith DESKTOPH prov ides
so me new command s.
• Version 4-A combinati on ofVersions
2 and 3.
The programs HALTER, HAL TERD , HAL ­
TERE , and HALTERDE are assoc iated w ith
V ersions I , 2, 3 and 4 res pectively, of
DESKTOPH . Each of these patch program s
gives the 0 command of DESKTOPH the
ability to transfer co ntrol to ORIVERHT or
DRIVERHE . Those of you with Epson or
Epson-compatible printers w ill have to
change Line 725 of the patch program
assoc iated w ith your version of DESKTOPH .
ln that line you w ill ha ve to replace DR I v­
ERHT with DR!VERHE .
Each patch program ex pand s the powers
of the 0 command further. It adds an
option to the 0 co mmand allowing you to
look at the directory of the disk in Dri ve 0.
For later prinring, you w ill be sav ing eight
or 12 sc ree ns on disk by mea ns of the Save
Screen option of th e 0 command. To keep
trac k of what f iles are already on the disk,
you may occasionally need to use the directory
option of the 0 command. Each patch
program gives DESKTOPH the ability, by
means of the 0 and I commands. to add ress
drives when sav ing and l oad ing sc reen
fi les. If you have more th an one drive, you
may want to save sc reen f iles on a disk in a
drive other than Drive 0. You should then
append to DIR in Line 725 a drive number
1, 2 or 3 correspond ing to th e dri ve you
intend to employ. Some of you hav ing
Version 2 or Version 4 of DESKTOPH may
need to change L ine 725 , by rep lac ing
THENCLS : EXEC&Hl49 w ith the BAS IC com-
mands in the corres ponding part of L ine
725 of your present DESKTOPH . For instance,
many of you using HDUMP10 5 sc reen clump
need to make the replacement:
THENCLS : PRJNT#-2,CHR$(27) : CHR$(20
: EXEC&Hl32A.
When you have typed the patch program
for DESKTOPH and made, if neeclecl , any of
the discussed chan ges in L ine 725 , save it
in ASCII f ormat. For example, to save
HAL TERD in ASCII fo rm at, type :
SAVE " HALTERD " , A and press ENTER.
Baud Rate
1200
2400
4800
9600
Table 1
Value
4 1
18
6 or 7
I
Tomakethenecessarya lterat ionofD ESK ­
TOPH, do the fo llowing: Get out the disk
containing your version of DESK TOP H and
its font fi les, then make a backup copy of
th e disk. Put away the ori ginal and work
w ith the back up copy. For compatibility
w ith 0 RIVE RHT or OR [ V ERH E, your DES KTO PH
version must have the fi lename DH . Therefore,
inse rt th e disk co ntaining DESKTO PH in
the dri ve and type: RENAME " DESKTOPH/
BAS " TO '' OH/BAS " and press ENTER . Now
enter LOAD " OH " , then insert in the drive the
disk containing the patch program -
HALTER . HALTERED, HAL TERE, or HAL TERDE .
If your patch program is HA L TERDE . for
instance, type: MERGE " HAL TERDE " and press
ENTER . Do similarl y for any one of the
other three patch pmgrams, but w ith its
name instead of HAL TERDE . Finally, insert
the disk containing DH in your drive and
type: SAVE " DH" and press ENTER.
Depend ing on what pri nter you have,
you may have to change some lines of th e
dri ve r program , ORIVERHT or DRIVERHE,
whichever one you will be using. The poke
command in Line 5 of eac h of these programs
is employed to set the baud rate of
your particul ar printer. If your prin ter operates
at 600 baud, you need not change Line
S. Otherwise, delete the apos trophe from
L ine 5 and replace the qu estion mark w ith
the va lue assoc iated w ith the baud rate of
your printer. These va lues are gi ven in
T able I . If the control codes for initiating
the 800 or 960 dots- per- line graph ics mode
are otherthan 27,20 or 27 , 19, res pectively,
for your DMP printer, you need to change
L ine 740 or 730 of DRI vE RHT , accordingly.
If you have a printer that is Epson-compatible
but not an Epson, you may have to
tailor-make DRI VER HE to fit the needs of
your printer. Tailor-m aking DRIVERHE involves
changing seven DATA statements
containing Epson printer-co ntrol code
sequences. Lines 650 through 670 contain
the control codes for a two-column printout.
Similarl y, lines 720 through 750 hold
control codes needed for three-colu mn
printouts. The first DATA value in eac h of th e
lines specifies the number of va lues in the
control code sequence represented by the
remainder of the DATA statement. Lines 650
and 720 are identica l and spec ify the control
code sequence for line spac ing.
For ordinary printing your printer provides
a line spacing of one-sixth inch, which
produces six lines of print per inch. For the
printer graphics modes the line spacing
must be a closer, 7/72 inch. The Epson
control code seq uence yielding the required
line spaci ng is 27 . 49 . In lines 650 and 720
the initial value of 2 indicates the following
va lues. 27 ancl 49 represent the control code
sequence. Chec k your printer manual to see
w hether or not 27 . 49 is the control code
sequence for a I ine spac ing of 7/72 inch. If
your printer has a different control code
sequence for that line spac ing, modify I ines
650 and 720 accordingly. If the control
code has three values, for instance, in addition
to changing the control code sequence,
you wi ll have to alter the initial value to 3.
In such a case, the DATA statement would
end with fou r zero values instead of the five
required for the Epson printer. It may be
that your printer automatically adjusts the
line spacing to f it the graphics modes. In
that event, you need to replace the initial
va lue 2 in lines 650 and 720 w ith 0. However,
if your printer does not have automatic
line spacing adjustment and you make
the 0 for 2 substitution, your printout w ill
show noticeable gaps between lines.
BAS IC lines 670 and 740 also dea l with
line spacing. They hold control code sequences
for the return to one-sixth inch I ine
spac ing. T herefore, check your manual for
a 27 , 50 control code sequence, and if needed,
make changes in lines 670 and 740 analogous
to those made for I in es 650 and 720.
Lines 660, 730 and 750 contain the Epson
control code sequences for specifying the
graphics modes. L ines 660 and 750 are
exactl y the same. The graphics mode indicated
by each of those two lines is the one
w ith a dot density of960dots per line ( 120
dots per inch). The fi rst two values, 192 and
3 indicate a m ax imum of 192+ 3*256=960
clots that are to be printed per line. If your
printer manual has a different control code
sequence for thi s graphics mode, be sure to
change I ines 660 and 750 so th at the codes
specify a maximum of960 dots printed per
line.
Line 730 holds the control seq uence for
August 1989 THE RAINBOW 39