[Coco] 6809 example

[Robert Gault]

Bob Emery wrote:
> Shouldn't there be a Y=0: at the beginning of line 30? ;-)
> Otherwise PASS will always max out since the flag isn't being reset.
> 
> Bob
> 
> --- Robert Gault <robert.gault at worldnet.att.net> wrote:
> 
>>Roger Taylor wrote:
>>
>>>The first ML program I ever typed in and saw run was, in fact, the 
>>>bubble sort example from William Barden's 6809 Assembly Language 
>>>Programming book. <snip>
>>
>>>----------
>>>Roger Taylor
>>>
>>>
>>
>>Good example of assembly code, but the least efficient method of 
>>sorting. Here is an equivalent version in Disk Basic for comparison.
>>
>>10 WIDTH32: FOR I=0TO511:POKEI+&H400,RND(0)*9+48:NEXT
>>20 REM BUBBLE SORT
>>30 FORX=&H400 TO &H5FE
>>40 A=PEEK(X):B=PEEK(X+1):IF B>A THEN POKEX,B:POKEX+1,A:Y=1
>>60 NEXT
>>70 PASS=PASS+1
>>80 IF Y<>0 THEN 30
>>90 GOTO 90
>>
>>With this version when all action stops, hit the BREAK key and PRINT 
>>PASS. With Roger's example it will not be quite as easy to examine
>>the 
>>pass counter.
>>
>>It is interesting that in this example, assembly code is almost as
>>easy 
>>to write and almost as short as Basic. That is because the tasks 
>>involved are ideal for assembly code. For only slightly more complex 
>>tasks, the size of the assembly code will balloon significantly vs
>>Basic.
>>
>>
>>-- 
>>Coco mailing list
>>Coco at maltedmedia.com
>>http://five.pairlist.net/mailman/listinfo/coco
> 
> 
> 
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No, because Disk Basic always zeros out variable on RUN. If you jump 
into the middle of a program with GOTOxyz there might be a problem. In 
any case, that is a point I was trying to make in this comparison. High 
level languages take care of initial conditions and loop counters 
(amongst other things), low level languages don't.