[Coco] BASIC09 - unsigned INTEGERs?

[K. Pruitt]

>
> ----- Original Message ----- 
> From: "K. Pruitt" <pruittk at roadrunner.com>
> To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
> Sent: Sunday, February 01, 2015 6:39 AM
> Subject: Re: [Coco] BASIC09 - unsigned INTEGERs?
>
>
>>
>> ----- Original Message ----- 
>> From: "Robert Gault" <robert.gault at att.net>
>> To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
>> Sent: Sunday, February 01, 2015 6:20 AM
>> Subject: Re: [Coco] BASIC09 - unsigned INTEGERs?
>>
>>
>>> Allen Huffman wrote:
>>>>> On Feb 1, 2015, at 7:45 AM, K. Pruitt <pruittk at roadrunner.com> wrote:
>>>>>
>>>>> This is from the rainbow mag and it does print the correct value:
>>>>>
>>>>> PROCEDURE filesize
>>>>> TYPE Registers=CC,A,B,DP:BYTE; X,Y,U:INTEGER
>>>>> DIM regs:Registers
>>>>> DIM path,callcode:BYTE
>>>>> OPEN #path,"test":READ
>>>>> callcode=$8D
>>>>> regs.A:=path
>>>>> regs.B=$02
>>>>> RUN SysCall(callcode,regs)
>>>>> CLOSE #path
>>>>> PRINT USING "'Filesize = $',2(h4)",regs.X; regs.U
>>>>>
>>>>> I created a file with a size of 92324 bytes and it prints out the 
>>>>> correct value of 000168A4.
>>>>>
>>>>> I guess the real question now is how do we get this result in to a 
>>>>> variable.
>>>>
>>>> Right. That code there is the example from the SYSCALL source code, 
>>>> apparently, from the OS-9 Level 1 days.
>>>>
>>>> http://www.cocopedia.com/wiki/index.php/SysCall.asm_Level_1 
>>>> <http://www.cocopedia.com/wiki/index.php/SysCall.asm_Level_1>
>>>>
>>>> — A
>>>>
>>>>
>>>>
>>>
>>> Well that might work given typical file sizes but for general math, 
>>> there are still problems. After some testing, it looks like a big 
>>> problem resides in PRINT USING.
>>>
>>> DIM a:INTEGER; b:REAL
>>> a=$FE
>>> b=a*16777216.
>>> PRINT b
>>> PRINT USING "h8",b
>>>
>>> 4.261141286E+09
>>> 20FE0000
>>>
>>> The real product is correct but PRINT USING can't convert to the correct 
>>> hexadecimal notation. The hex answer is $FE000000.
>>>
>>> Robert
>>>
>>>
>>
>>
>> Yeah, you're right regarding general math use.  But as far as sizing 
>> files, what would you consider as a reasonable maximum to shoot for?
>>
>>
>
>
> I think I answered my own question.  If my math is correct the largest 
> file size possible to be reported by syscall in two 16 byte registers is 
> 4294967295.
>

I mean two 16-BIT registers.  I didn't discover some new mega registers.