Qbasic cvs problem

[Dan English]

I am converting a qbasic application to powerbasic and have a problem with the data in random access files. Quite a few fields are stored as packed 4 byte single with MKS. When read by powerbasic with CVS it dosen't return the correct value. I've tried every combination to unpack ie CVL, CVS, CVQ, even CVE but don't get the right value. The 2 byte convert fine. Does anyone know if there is something else I need to do?

[Manuel Valdes]

Dan:

May be the file uses the MS format for single precision values. Power Basic for DOS have a function (CVMS) to deal with that non-standard format, but PBCC doesn't. May be you can make an applet to process the files prior to use them with your new programm.

[Scott Slater]

Have you tried reversing the input string? ie. Cvs(StrReverse$(InVal$))

[Guy Dombrowski]

Dan,
I do not understand your problem as the CVS function will convert correctly all my QBASIC SINGLE random files ?
All the other types also work perfectly.
Can you show us some failing code ?

[Steve Rossell]

This will work. Try creating a small QB program that creates a file with some data and a PB program that reads this file. If it does not work, then please post the code here and we will see what is wrong.

[Arthur Gomide]

Maybe this help!

[Bob Zale]

Actually, QBasic uses the IEEE format, same as PowerBASIC. There's no need to try to convert to/from the old MBF.

Bob Zale

[Michael Mattias]

Actually, QBasic uses the IEEE format, same as PowerBASIC. There's no need to try to convert to/from the old MBF.

Unless..... the term "qbasic" here has been (mis-)used and it should have have been "QuickBasic."

QuickBasic DID use MBF, athough there was (is?) a command-line compiler override to use IEEE instead. Or maybe it was IEEE by default, with override to MBF... I know it's one of those because I had to use it.

MCM

[Manuel Valdes]

Steve Rossell, Bob Zale, Michael Mattias......... God, what am I doing here!

I think we should wait for a word from Dan.

May be. Just may be, he is dealing with "legacy" files produced by a very old QuickBasic program, using MBF.

[Guy Dombrowski]

QuickBasic was IEEE by default.
You had to use the /MBF option when starting the compiler in order to convert to MBF mode

[Michael Mattias]

>what am I doing here!

Mining for Old Farts and hitting a rich vein?

[Dan English]

QuickBasic

Sorry for the misunderstanding, this app was written in MS Quick Basic. The compiler batch file is:

BC %1,,, /MBF/W/Fs/D/E/Es/AH
LINK /E %1

We are using the FIELD statement as is and all the data except the "4P (4 Byte packed)" fields are read fine. Here is an example, the variable is "S14" With the QuickBasic code "S14 = CVS(S14$)" returns 112

With PowerBasic I read the file and printed the contents of S14 raw, then with each CV* function. The last one (ABC) is with the assembler code that was posted yesterday.

S14: `ç
S14-Integer: 0
S14-Long: 2271215616
S14-Single: -1.685189E-34
S14-Extend: 0
S14-Double: 1.12212961016376E-314
S14-Double Word: 2271215616
S14-LONG: -2023751680
ABC: 0

[Michael Mattias]

Given what current program is doing and how it's compiled, the MBF functions in that ZIP file attached to post #6 should handle your problem promptly.

Instead of "CVS(field variable)" you'll have to use "CVMS (field variable)" in your code, making sure the DECLARE..

 
DECLARE FUNCTION CVMS LIB "MSBF.DLL" (x AS STRING) AS SINGLE

.. is in your code and the DLL is available to the EXE.

[Arthur Gomide]

> Instead of "CVS(field variable)" you'll have to use "CVMS (field variable)" in your code, making sure the DECLARE..

Must be a "string variable" here ... or a compilation error occurs using CC5!

[Michael Mattias]

>Must be a "string variable" here

Forgot... there now is a type FIELD variable.

I got my printed manual about a week ago. I took it out of the mailing envelope, but it's still in the shrink wrap. I got that because just surfing through a manual, you can find all the new and improved stuff a lot easier than trying to divine it from the help file.

Rumor has it there is lots of new stuff since my last printed manual... PB/DLL version 2.0

(The "new" I can usually remember, but the "Improved!" go right past me).

Guess I'll have to break that open and put it somewhere I often sit with not a heck of lot else to do except read.

MCM

[John Petty]

Of course if you still have QuickBasic they have the conversion functions as standard ie CVSMBF and CVDMBF so you should be able to write a converter. They were still there in my copies of QB4.5 and BC7.1, can't quickly find my Windows for DOS 1 but think they were in that as well. Default mode for all the was IEEE.

[Guy Dombrowski]

I often sit with not a heck of a lot to do

Now we know the real reason for those 22k post from MCM

[Arthur Gomide]

#COMPILE EXE
#DIM ALL

' PowerBASIC declarations for MSBF.DLL functions
DECLARE FUNCTION CVMS LIB "MSBF.DLL" (x AS STRING) AS SINGLE
DECLARE FUNCTION MKMS LIB "MSBF.DLL" (BYVAL s AS SINGLE) AS STRING
DECLARE FUNCTION CVMD LIB "MSBF.DLL" (x AS STRING) AS DOUBLE
DECLARE FUNCTION MKMD LIB "MSBF.DLL" (BYVAL d AS DOUBLE) AS STRING

FUNCTION PBMAIN () AS LONG

    LOCAL s,d AS FIELD
    'local a as single
    'local b as double

    OPEN "gwbf.bin" FOR RANDOM AS #1 LEN=12
    FIELD #1, 4 AS s, 8 AS d
    GET #1,1
    'FIELD STRING s,d
    'CLOSE #1
    PRINT CVMS(s); CVMD(d)

    WAITKEY$
    CLOSE #1


END FUNCTION


PowerBASIC Console Compiler
PB/CC   Version 5.01 
Copyright (c) 1998-2009 PowerBasic Inc.
Venice, Florida USA
All Rights Reserved

Error 480 in F:\PBCC50\Cvrtgwbf.bas(21:017):  Parameter mismatches definition
Line 21:     PRINT CVMS(s); CVMD(d)

If I change the "x as string" to "x as field" in declares it compiles but I receive a gpf.

[Michael Mattias]

The CVMS and CVMD functions hould be declared with param "AS STRING."

I only used the word FIELD because you had FIELDed a buffer in you code... I FORGOT there is now a "FIELD" data type in PB and I should never have used that (now magic) word in this post.

As far as the GPF... if you don't have data that might be the problem. ie., file 'gwbf.bin' not found, and was created empty, meaning you would be passing garbage to the CVMS function.

[Dan English]

Solved

Thanks for all the responses, we have a solution. The only additional change is that a FIELD is not exactly the string the function was expecting. We had to change the field to a string then use the CVMS function on the string. It works great!