Keyword Takeover By The Hp 82718A; Abbreviating Keywords - HP 82718A Expansion Pod Reference Manual

,
,
KEYWORD TAKEOVER AND
III
~D_U_PL_I_C_A_T_E_K_E_Y_W_O_R_D_S
__________
~~
KEYWORD TAKEOVER BY THE HP 82718A
It is important that the final form of software being distributed is compatible with the intended hardware
configuration. One issue related to this is keyword takeover. HP-75 BASIC programs are stored in a
compact internal form. If the program includes keywords from plug-in ROMs, the ROM ID of the ROM
is used as part of the internal representation of that keyword in the program. If the ROM has been
removed when the program is run, the program will not be able to find the ROM and execute the
keyword. The program will then halt and display
EF.:POP: F.:Ot'1
f'1
i
ss
i n'~
at the line containing the
missing command.
Seven of the keywords in the HP 8271 8A have the same names as keywords in the HP-75 operating
system:
CI~T,
CAT!,* CAT ALL, COP'"!"', I
t·~
I T I AL I ZE, PUPGE,
and
F.:Et·mt'1E.
The keywords in the
HP 8271 8A will always override those in the HP-7 5, hence the term
keyword takeover.
To see the effect of the HP 8271 8A taking over a keyword, look at an example. Type in a program
containing the line
PUF-::GE "ABC"
on an HP-75 installed in an HP 827l8A. Copy the program onto a
card, and then copy the card into a stand-alone HP-75. When you run the program in the stand-alone
HP-75, you will get
EPF.:OF.:: Pot'1
[01
i ::::~::: i
n9. The internal form of the program has the ROM ID of
the HP 827l8A
PUPGE
command, not the
PUPGE
command of the HP-75. Even though
PUPGE
"ABC"
does not require the electronic disc, because the program was created using an HP 8271 SA, its
ROMs must be present for the program to run.
A similar situation occurs going the other direction. Type in a program containing the line
P UPGE
"ABC: >=:t'1Et'1"
on a stand-alone HP-75.
(If
you were to run this program on the HP-75, you would see
EPPOP:
in' .
..'.::d id f i
lE'spE'c~
stand-alone HP-75 does not recognize the
::·::t-1Et'1
device code.)
Copy the program onto a card, and then copy the card into an HP-7 5 installed in an HP 827l8A. When
you run the program, you will still get
EFPOF.:: i nl . ..'.::tl i d f i
1 E'spec. The internal form of the
program does not have the ROM ID of the HP 827l8A
PUF.:GE
command, but instead has the HP-75
PUPGE
command. Even though
PUF.:CiE "AE:C: ::·::t'1Et'1"
is meant for the electronic disc, because the
program was created without an HP 827l8A, the program will not access the electronic disc.
You can avoid problems of keyword takeover simply by using the
TPAt·~::::FOPt'1
command when moving
BASIC programs from one HP-75 configuration to another. First, convert the program into a text file
(TF.:At-~::;FOF.:t'1
"filename" I HTO TE>::1").
Then copy the text file from the source HP-75 to a
mass storage device. Read it into the destination HP-75, and convert the text file into a BASIC program
(TF.:At·~SFOF.:t'1 "filename"
I t·no
BI~::;
I C).
ABBREVIA TING KEYWORDS
The same idiosyncracies that give problems with keyword takeover will also create difficulties with
abbreviated keywords. The HP-7 5 gives you the option of abbreviating keywords when you type them in,
such as
PU.
for
PUF.:GE.
The HP-75 recognizes abbreviated keywords as the HP-75 version of that
*CAT!
in the HP 82718A performs identically as
CAT!
in the HP-75.
107