[Coco] Syscall

[L. Curtis Boyle]

That’s the entire program? Is their a PROCEDURE (program name) above what you have shown here?

Sent from my iPhone

> On Mar 3, 2018, at 7:12 PM, phil pt <ptaylor2446 at gmail.com> wrote:
> 
> Here is the code
> 
> TYPE r=cc,a,b,dp:BYTE; x,y,u:INTEGER
> DIM regs:r
> 
> 
> 10 regs.a=0                             \ (* <-std input *)
> regs.b=$26                              \ (* <-SS.ScSiz *)
> RUN syscall($8D,regs)
> sizeX=regs.x                            \ (* Window Width *)
> sizeY=regs.y                            \ (* Window Length *)
> 
> 
> On Sat, Mar 3, 2018 at 5:19 AM, L. Curtis Boyle <curtisboyle at sasktel.net>
> wrote:
> 
>> How big of a buffer space are allocating BASIC09 (when you invoke it from
>> the command line)? Wayne is right in that it will consume a lot more RAM
>> when merged with RUNB. This is because every user program gets a maximum
>> (without fancy things like CHAIN, etc) 63.5K workspace. And each time you
>> load program modules (like BASIC09, RUNB, etc, they get loaded into MMU
>> blocks of RAM (each MMU block is 8K). OS-9/Nitros9 loads programs at the
>> highest point of available RAM your 64k workspace, in MMU sized chunks.
>> (There is 512 bytes at the very top that is reserved for I/O with hardware,
>> and the task switching part of the kernal, so that is off limits to you and
>> your programs). So, if your program (or merged programs) take 7.5k or less,
>> it will take the full 7.5K (because the MMU can only map fixed sized
>> blocks). If they take between 7.5K and 15.5K, it will take the full 15.5K,
>> etc (just keep adding 8k).
>> So, if you load BASIC09 (which is 23k, roughly), that will take 23.5k
>> from your 63.5k (plus at least 8k for its internal variables, and your
>> procedures).  If you have syscall, etc merged with RUNB, when it try’s to
>> add that into your workspace, it brings the entire merged chunk in (and
>> since RUNB itself is about 12k, that gets rounded up to 16k for the MMU -
>> you now have 23.5k for BASIC09, 16K for RUNB, syscall, inlet, etc) plus at
>> least 8k for your procedures, etc - so you are at least taking up 48k of
>> your workspace. If your program is bigger, you rapidly run out of room.
>> Depending on the size of your program, you could UNLINK RUNB and it’s
>> merged modules until you get an error 221 (which means it is really out of
>> RAM, and then load in a merged file of inkey , syscall and your other