[Coco] Absolute Memory Location

[Jeff Teunissen]

OS9 does have named pipes, but they're not enabled by default. You
need the version of PipeMan that supports them. You can also get
shared memory by linking to a "data module". Every CoCo OS9 boot file
has a data module named "Init" in it containing the name of the boot
drive and a few other things.

On Sat, Aug 15, 2020 at 9:46 PM <coco at jechar.ca> wrote:
>
> Trying to implement some inter-process communication was hoping
> to not have to settle for having to write to a temporary disk
> file and then read it. It seems there should be some memory only
> way to pass info.
>
> NOW THIS IS FANTASY but it is the sort of thing that would be
> useful.
>
> For example if there was a function like this:
>
> DIM block:BYTE
> DIM rokey$,rwkey$:STRING[200]
>
> RUN BUFFS("CREATE",block,rokey$,rwkey$)
>
> Where block,rokey$ and rwkey$ cannot be set but only read
> except that if rwkey$="NO" means that no other process can
> write to the memory.
>
> Then if you say
>
> returnval$="UNPROCESSED"
> key$=rwkey$
> SHELL "someProgram "+returnval$+key$
>
> in "someProgram" say your code assigns returnval$="NEW VALUE"
>
> looping through
> BPOKE key$,address,bytevalue
>
> Where BPOKE lets you poke into the buffer with the given rwkey
>
> There would also be a x = BPEEK(key$,byteval) where key$ may be
> either rwkey or rokey
>
> Of course the OS would have to manage the keys to make sure that
> there were no duplication although duplication would be unlikely
> in a 200 character key.
>
> Also If the key is to be so long there should be some way that the
> first time the key is checked by BPEEK or BPOKE and checks out as
> ok then additional calls from the same process do not need to recheck.
>
> Also note valid values for address would be 0 to 8191 since these
> buffers are 8K blocks.
>
> Finally RUN BUFFS("CLOSE",block)
> where you can only close the block if you opened it in the
> first palace.
>
> But of course RUN BUFFS() , BPEEK and BPOKE are a FANTASY.
>
> I think  I heard of something called "NAMED PIPES" that might
> work if OS9 has them.
>
> On 2020-08-15 19:40, Rick Ulland wrote:
> > Not really.
> >
> > Really.
> >
> > In EDECB you have LPOKE, but there you own the machine and are free to
> > crash it. Basic09 runs underneath the OS9 system - you do not know
> > what is going on outside your process space and are not free to change
> > anything out there. You can hack some things. Your users will hate
> > you.
> >
> > This might be the X=Y problem. What are you wanting to do that
> > requires smashing an absolute memory location to a fixed value from
> > inside Basic?
> >
> > -rick
> >
> >
> >
> > On 8/15/20 4:27 PM, coco at jechar.ca wrote:
> >>
> >>  Is there any assembly program or syscall that can let you
> >>  put values in an ABSOLUTE location ( Specified MMU bank and
> >>  ADDRESS ). This program would need to be callable from Basic09.
> >>
> >>  Charlie.
> >>
>
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