Can static arrays be shared ??

[Franco Lazzarotti]

Hi !

I have no real experience with PB programming, so maybe I'm doing something wrong.. anyway I'm having problems accessing an array (declared as STATIC and SHARED) from a SUB.
It seems I can't access more than 255 elements.
Maybe static arrays can't be shared ?? That is, they can't be global ??? The array has 512 elements.
If I remove the code from the SUB and put it in the global scope, I can access all the elements correctly.
If so, should I pass the memory pointer of the array to my SUB ?

Thanks for any help.

Here it is the source (it prints bitmap fonts on a dot-matrix display connected through parallel port) :

'$COMPILE UNIT
'$COMPILE EXE
$CPU 80386
$LIB LPT OFF
$LIB GRAPH OFF
$LIB FULLFLOAT OFF
$LIB IPRINT OFF
'$ERROR ALL OFF
$OPTION CNTLBREAK OFF

DEFINT A-Z

DECLARE SUB DisplayTextOut(StringToDisplay AS STRING)
DECLARE SUB DoEnablePulse(BYVAL RegisterStatus AS BYTE)

DIM STATIC BUFFER_FONT8x8(511) AS SHARED BYTE

' SPAZIO
BUFFER_FONT8x8(0)=0
BUFFER_FONT8x8(1)=0
BUFFER_FONT8x8(2)=0
BUFFER_FONT8x8(3)=0
BUFFER_FONT8x8(4)=0
BUFFER_FONT8x8(5)=0
BUFFER_FONT8x8(6)=0
BUFFER_FONT8x8(7)=0
'
BUFFER_FONT8x8(488)=0
BUFFER_FONT8x8(489)=0
BUFFER_FONT8x8(490)=65
BUFFER_FONT8x8(491)=65
BUFFER_FONT8x8(492)=127
BUFFER_FONT8x8(493)=127
BUFFER_FONT8x8(494)=0
BUFFER_FONT8x8(495)=0
'
BUFFER_FONT8x8(496)=0
BUFFER_FONT8x8(497)=8
BUFFER_FONT8x8(498)=12
BUFFER_FONT8x8(499)=254
BUFFER_FONT8x8(500)=254
BUFFER_FONT8x8(501)=12
BUFFER_FONT8x8(502)=8
BUFFER_FONT8x8(503)=0
'
BUFFER_FONT8x8(504)=0
BUFFER_FONT8x8(505)=24
BUFFER_FONT8x8(506)=60
BUFFER_FONT8x8(507)=126
BUFFER_FONT8x8(508)=24
BUFFER_FONT8x8(509)=24
BUFFER_FONT8x8(510)=24
BUFFER_FONT8x8(511)=24

' Display OFF
'OUT &H37A,7
'OUT &H378,&H3E
'CALL DoEnablePulse(7)

' Set the Initial Display Line
'OUT &H378,&HC0
'CALL DoEnablePulse(7)

' Set Page Address
'OUT &H378,&HB8
'CALL DoEnablePulse(7)

' Set Y Address
'OUT &H378,&H40
'CALL DoEnablePulse(7)

CALL DisplayTextOut("A")

' Display ON
'OUT &H37A,7
'OUT &H378,&H3F
'CALL DoEnablePulse(7)

SUB DisplayTextOut(StringToDisplay AS STRING)
 DIM i AS LOCAL BYTE
 DIM y AS LOCAL BYTE
 DIM Lenght AS LOCAL BYTE
 DIM Offset_Start AS LOCAL WORD
 DIM Offset_End AS LOCAL WORD

 Length=LEN(StringToDisplay)
 IF Length<17 THEN
	'OUT &H37A,6
	FOR i=1 to Length
		'y=ASC(StringToDisplay,i)
                'PRINT y
		Offset_Start=ASC(StringToDisplay,i)-32
		SHIFT LEFT Offset_Start,3
        	Offset_End=Offset_Start+7
                PRINT Offset_Start
        	' Write BitMap Data
        	FOR y=Offset_Start TO Offset_End
	                PRINT BUFFER_FONT8x8(y)
			'OUT &H378,BUFFER_FONT8x8(y)
 			'CALL DoEnablePulse(6)
		NEXT
 	NEXT
 END IF
END SUB

SUB DoEnablePulse(BYVAL RegisterStatus AS BYTE)
 DIM i AS LOCAL BYTE
 ' E=0
 OUT &H37A,RegisterStatus-4
 FOR i=0 to 1
 NEXT i
 ' E=1
 OUT &H37A,RegisterStatus
END SUB

[This message has been edited by Franco Lazzarotti (edited August 19, 2006).]

[Paul Dixon]

Franco,
there is no point making an array STATIC and SHARED at the same time. Just make it SHARED.

Your code produces an overflow error on the line:

   FOR y=Offset_Start TO Offset_End

The error is because y is define as a BYTE but it's being allocated a value of 264 which is beyond the range of a BYTE.

Paul.

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[Michael Mattias]

Or pass the entire array as an additional parameter to using subs...

Main:
   STATIC  Z() AS LONG
  ....
   ....
   CALL myfunction (A,b, c, [b]Z()[/b])
   ....

    END

FUNCTION MyFunction (A AS integer, b as integer, c as integer, [b]Z() AS LONG[/b])

 ' you can do anything you want with Z() in this function

END FUNCTION
...

[Mel Bishop]

I have no real experience with PB programming

Just as a programming tip, you can save yourself a heck of a
lot of typing by using Data statements. Example for your
program:

data 0,  0,  0,  0,  0,  0,  0,  0
data 0,  0,  0, 79, 79,  0,  0,  0
for x = 1 to finish
t$ = read$
BUFFER_FONT8x8(x) = val(t$)
next x

It's been a while since I used data statements in a DOS program
so the syntax may be a little off, but it should give you the
idea.


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[This message has been edited by Mel Bishop (edited August 01, 2006).]

[Arthur Gomide]

[quote]Originally posted by Mel Bishop:

It's been a while since I used data statements in a DOS program
so the syntax may be a little off, but it should give you the
idea.

DATA 0, 0, 0, 0, 0, 0, 0, 0:' spazio
DATA 0, 0, 0, 79, 79, 0, 0, 0:' !
DATA 0, 7, 7, 0, 0, 7, 7, 0:' "
DATA 20,127,127, 20, 20,127,127, 20:' #
DATA 0, 36, 46,107,107, 58, 18, 0:' $
DATA 0, 99, 51, 24, 12,102, 99, 0:' %
DATA 0, 50,127, 77, 77,119,114, 80:' &
DATA 0, 0, 0, 4, 6, 3, 1, 0:' '
DATA 0, 0, 28, 62, 99, 65, 0, 0:' (
DATA 0, 0, 65, 99, 62, 28, 0, 0:' )
DATA 8, 42, 62, 28, 28, 62, 42, 8:' *
DATA 0, 8, 8, 62, 62, 8, 8, 0:' +
DATA 0, 0,128,224, 96, 0, 0, 0:' ,
DATA 0, 8, 8, 8, 8, 8, 8, 0:' -
DATA 0, 0, 0, 96, 96, 0, 0, 0:' .
DATA 0, 64, 96, 48, 24, 12, 6, 2:' /
DATA 0, 62,127, 73, 69,127, 62, 0:' 0
DATA 0, 64, 68,127,127, 64, 64, 0:' 1
DATA 0, 98,115, 81, 73, 79, 70, 0:' 2
DATA 0, 34, 99, 73, 73,127, 54, 0:' 3
DATA 0, 24, 24, 20, 22,127,127, 16:' 4
DATA 0, 39,103, 69, 69,125, 57, 0:' 5
DATA 0, 62,127, 73, 73,123, 50, 0:' 6
DATA 0, 3, 3,121,125, 7, 3, 0:' 7
DATA 0, 54,127, 73, 73,127, 54, 0:' 8
DATA 0, 38,111, 73, 73,127, 62, 0:' 9
DATA 0, 0, 0, 36, 36, 0, 0, 0:' :
DATA 0, 0,128,228,100, 0, 0, 0:' ;
DATA 0, 8, 28, 54, 99, 65, 65, 0:' <
DATA 0, 20, 20, 20, 20, 20, 20, 0:' =
DATA 0, 65, 65, 99, 54, 28, 8, 0:' >
DATA 0, 2, 3, 81, 89, 15, 6, 0:' ?
DATA 0, 62,127, 65, 77, 79, 46, 0:' @
DATA 0,124,126, 11, 11,126,124, 0:' A
DATA 0,127,127, 73, 73,127, 54, 0:' B
DATA 0, 62,127, 65, 65, 99, 34, 0:' C
DATA 0,127,127, 65, 99, 62, 28, 0:' D
DATA 0,127,127, 73, 73, 65, 65, 0:' E
DATA 0, 95,127, 9, 9, 1, 1, 0:' F
DATA 0, 62,127, 65, 73,123, 58, 0:' G
DATA 0,127,127, 8, 8,127,127, 0:' H
DATA 0, 0, 65,127,127, 65, 0, 0:' I
DATA 0, 32, 96, 65,127, 63, 1, 0:' J
DATA 0,127,127, 28, 54, 99, 65, 0:' K
DATA 0,127,127, 64, 64, 64, 64, 0:' L
DATA 0,127,127, 6, 12, 6,127,127:' M
DATA 0,127,127, 14, 28,127,127, 0:' N
DATA 0, 62,127, 65, 65,127, 62, 0:' O
DATA 0,127,127, 9, 9, 15, 6, 0:' P
DATA 0, 30, 63, 33, 97,127, 94, 0:' Q
DATA 0,127,127, 25, 57,111, 70, 0:' R
DATA 0, 38,111, 73, 73,123, 50, 0:' S
DATA 0, 1, 1,127,127, 1, 1, 0:' T
DATA 0, 63,127, 64, 64,127, 63, 0:' U
DATA 0, 31, 63, 96, 96, 63, 31, 0:' V
DATA 0,127,127, 48, 24, 48,127,127:' W
DATA 0, 99,119, 28, 28,119, 99, 0:' X
DATA 0, 7, 15,120,120, 15, 7, 0:' Y
DATA 0, 97,113, 89, 77, 71, 67, 0:' Z
DATA 0, 0,127,127, 65, 65, 0, 0:'
DATA 0, 62,127,127,127,127, 62, 0:'
DATA 0, 0, 65, 65,127,127, 0, 0:'
DATA 0, 8, 12,254,254, 12, 8, 0:'
DATA 0, 24, 60,126, 24, 24, 24, 24:'

DIM Buffer_Font8x8(511) AS SHARED BYTE
DIM Counter AS INTEGER

FOR Counter = 0 TO 511
READ Buffer_Font8x8(Counter)
PRINT Buffer_Font8x8(Counter);
NEXT Counter

END

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[Franco Lazzarotti]

Thank alls for suggestions and help. Actually the problem was a wrong variable declaration. After that, it works fine. I'm thinking of passing the pointer, maybe it could be a little faster than accessing a global buffer ? As regards the using of 'DATA' statements, that series of 'BUFFER_FONT8x8[n]=d' was created automatically by a program I made to convert bitmap fonts, so that's the best choice. Thank you.



[This message has been edited by Franco Lazzarotti (edited August 19, 2006).]

[Michael Mattias]

>>I'm thinking of passing the pointer,
>>maybe it could be a little faster than accessing a global buffer

??

Passing a pointer is exactly the same thing as passing the data item itself by reference (the default).

As far as 'faster' there are so many other variables involved the only true test will be... an actual test.

But in general, tinkering with passing a pointer versus the variable itself it will make no measurable leave alone noticeable difference.

But if a variable is global, why pass it at all? That just says "I made this variable GLOBAL (well, SHARED in PB/DOS-speak) for no good reason."

[Mike Doty]

'As Michael said, global isn't needed.
'In PB/WIN PB/CC, anyway, arrays are passed by BYREF very fast

#COMPILE EXE
#DIM ALL
FUNCTION PBMAIN () AS LONG
  LOCAL x() AS LONG
  LOCAL y AS LONG
  DIM  x(99)
  FOR y = 1 TO 10000000
    CALL test1(x())     'only address passed
  NEXT
  PRINT x(0), x(99)
  SLEEP 1000
  'result 10000000, -10000000
END FUNCTION

SUB Test1(BYREF x()AS LONG) 'BYREF is default
  INCR x(0)
  DECR  x(99)
END SUB

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