[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.