›()()()()()()()()()()()()()()()()()()()›› (This is an old article, full of info›and well worth reprinting today. Ye Ol›Editor)››         TURBO-BASIC›           THE FIRST REPORT›              By Ken Ward›                The    Norwich   Users›Group›Norwich, England›Febuary, 1987››The  biggest  problem we've had in the›past  was with alternative BASIC's for›the  Atari  has  been  the  cost.  OSS›produced   an   excellent   range   of›language  cartridges,  but  they  have›been very expensive.  Now, Turbo-BASIC›has  changed  all  that.   It's  a low›cost, (found in any Users Cub Library,›Editor)  extended BASIC which not only›offers   a   fantastic  range  of  new›commands,  but also speeds up all your›existing Atari BASIC programs.››When  we  offered  it  as  part of the›"World  of  Atari"  collection, we had›only  had time for a quick look at it.›Here is a our first report.››TESTING ITS SPEED››Turbo-BASIC  flies!  It runs all Atari›BASIC  programs  3  to 5 times faster!›To try to assess the speed difference,›we ran a simple test program:››          10   FOR   X=0   TO   2:POKE›18+X,0:NEXT X›          20 FOR X=1 TO 1000›          30 KEN=1256*22/7›          40 NEXT X›          50 7 PK(18)››This  program  was tried in both Atari›and  Turbo BASICs, with different line›30's.   In most cases, Turbo BASIC was›at  least  3  times  faster.   We also›tagged  the  routine to the front of a›lengthy  program,  and  a GOSUB to the›end  of the program as line 30.  Turbo›BASIC   came   out  of  this  test  an›incredible 11 times faster!!››In  fact,  its  speed  seems to be the›main problem you'll have running Atari›BASIC  programs  in  Turbo  BASIC!  In›some  programs,  you  will have to add›delay loops to slow it down!››PROBLEMS WITH BAD PROGRAMMING››I  have  come  across one program that›was a bit of trouble, but that was due›to   poor   programming   (which   was›surprising,    because   it   was   an›"A.N.A.L.O.G." program).››In  the  initializing  section  of the›program  there was the usual modifying›of the display list by using:››         ›DLIST=PEEK(560)+256*PEEK(561)››and then at the end of the init he had›added   another   mod.    By   POKEing›directly  into  where the display list›would have been in Atari BASIC instead›of using the DLIST pointer!››The other problem was more intriguing.› It centered around aloop like this:››          10     POKE     764,255:POKE›53279,10›          20 IF PEEK(764)=20 THEN 100›          30 IF PEEK(764)=20 THEN 200›          40   IF  PEEK(53279)=5  THEN›300›          50   IF  PEEK(53279)=4  THEN›400›          60 GOTO 10››It  worked  OK  in  Atari BASIC but in›Turbo  it  popped  straight out of the›loops  at  line  40,  even  though the›SELECT  key  had not been touched!  We›found  that  adding a short delay loop›at  line  15  allowed the loop to work›correctly,  as  did POKEing 53279 with›8in  line  10,  which  is  the correct›value to clear the CONSOLE keys.››TURBO BASIC MEMORY MAP››Turbo BASIc is a full 16K of code, yet›it  gives  you  another  1.5K  of free›memory over Atari BASIC!››The  bulk  of  Turbo  BASIc  is hidden›under  the Operating System ROM at the›top of memory.  The VBLANK routine has›been  modified  to  flip  between  the›twinned memory blocks, allowing access›to both areas.››The  rest  of  Turbo BASIc sits in the›block      from     8320($2080)     to›13864($9018).   This  is  in  the area›normally  used  by  DOS(and  DUP  when›loaded),   which  explains  why  after›calling  DOS  you  cannot  go  back to›Turbo  BASIC...which  in turn explains›why  DOS  commands  have been added to›the language.››Note     that     because    of    the›re-arrangement  of  memory,  the  area›occupied  by  the  screen  and display›list  at  the  top,  and  the variable›tables, etc. at the bottom, are in new›positions.    Providing  you  use  the›pointers  to  find their new locations›you'll be OK.››FORMATTING DISKS››The  only  useful  DOS command that is›missing  from  Turbo  BASIC is FORMAT.›However,  if you do get stuck and need›to   format   another  disk,  the  XIO›commands still work.››XIO  254,#1,0,0,"D:"  formats  in  the›default  drive  format.  If you have a›1050  and you need to format in single›density, use 253.››CHANGING VARIABLE NAMES››The  major  problem I've found with my›own  programs isthat I have been using›variable  names  that  are commands in›Turbo  BASIC!   Names like MOVE, TEXT,›DIR,  MOD,  DEC, and HEX$ are among my›favorites.!   And, of course, it means›I've  had to rename them to stop Turbo›BASIC erroring out.››Going  through  the programs modifying›every occurrance of a name can be time›consuming  if  there is a lot of them.›One way out is to use a word processor›in "Search and Replace" mode, but that›means  LISTing  the  program  out  and›booting in the word processor.  Again,›time   consuming.    In  the  end,  it›prompted  me to write my first routine›in Turbo BASIC.››Type  in  the  program  and LIST it to›disk.   You  then load the program you›need  to  modify,  ENTER  the  Renamer›routine, and run it with G.32000.››HOW IT WORKS››In  line  32070  we find the length of›the  variable table and dimension KEN$›accordingly.   The next two lines fill›KEN$ with complete list of variables.››The  end  of  a  variable is marked by›being  an inverse character, so in the›next   loo,   which   prints  all  the›variables  onto  the  screen, we check›for   an  inverse  character  at  line›32120,  and convert it before printing›it.   If there are a lot of variables,›use  CONTROL-1  to freeze/unfreeze the›screen.››You  are  then  asked for the variable›you  want  to rename.  Include the '('›if  it's an array, and the '$' if it's›a string.››By  printing  the name you've typed in›and   positioning  the  cursor  before›getting an input, saves you the bother›of  typing in the complete name.  Just›modify  one  or  two  letters  and hit›RETURN.››A  check is then made to make sure the›names  are  the  same  length.   (This›subroutine     only    modifies    the›particular  name - it doens't re-write›the complete variable table).››The  last character of our first input›is  then  inversed  before  using  the›INSTR  command to find its position in›the variable table.  If X= then you've›tried   to   modify  a  variable  that›doesn't exist!››If  all is well, the last character of›the  new name is inversed before using›the  MOVE command to move the new name›into the table area.››And,  that's all there is to it. Don't›forget the programs you modify must be›SAVEd  files.   LISTed files won't put›the  names  into the variable table in›the  first place - the lines will just›error out.››We haven't bothered with TYPO codes on›this one - the easiest way to check it›is  to  run  it by itself(after you've›LISTed   out   a   copy  to  disk,  of›course!).    After   you've   run  the›program,  LIST  it  on  the  screen to›check the changed names.››32000 REM ************************›32010 REM * VARIABLE RENAMER FOR *›32020 REM * USE WITH TURBO BASIC *›32030 REM * KEN WARD 8TH JAN 87  *›32040 REM * NORWICH USERS GROUP  *›32050 REM ************************›32060 REM›32070             CLR             :CLS›:N=DPEEK(132)-DPEEK(130):DIM›KEN$(N),VAR$(30),NXT$(30)›32080        KEN$="        ":KEN$(N)="›":KEN$(2)=KEN$›32090 MOVE DPEEK(130),ADR(KEN$),N›32100 POSITION 2,0›32110 FOR X=1 TO LEN(KEN$)›32120   Y=ASC(KEN$(X,X)):IF Y>127 THEN›Y=7-128:? CHR$(Y):GOTO 32140›32130   ? CHR$(Y);›32140 NEXT X›32150  ?  "What  is  the  name  of the›variable   you":?   "want   to  rename›";:INPUT VAR$›32160  ?  "Please  type  in new name -›REMEMBER   -":?  "name  must  be  same›length!":?     "      ";VAR$;:POSITION›2,PEEK(84)›32170           INPUT          NXT$:IF›LEN(NXT$)<>LEN(VAR$)  THEN ? "<-":GOTO›32160›32180›Y=ASC(VAR$(LEN(VAR$)))+128:VAR$(LEN(VA›$))=CHR$(Y)›32190 X=INSTR(KEN$,VAR$):IF X=0 THEN ?›"<-":GOTO 32150›32200›Y=ASC(NXT$(LEN(NXT$)))+128:NXT$(LEN(NX›$))=CHR$(Y)›32210                             MOVE›ADR(NXT$),DPEEK(130)+X-1,LEN(NXT$)›› ......****......*****.......****.....››                                      ›