¢()()()()()()()()()()()()()()()()()()()¢¢ (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$),DPEEK(130)+X-1,LEN(NXT$)¢¢ ......****......*****.......****.....¢¢ ¢
