🚀 go-pugleaf

Sam Shim writes:

> I'm doing some C programming using interrupts and I was wondering if
> it's possible to have a program save data from within a interrupt
> routine or if it is not possible due to the non re-entrant nature of DOS.

Oh, it's POSSIBLE all right.  It requires that your interrupt handlers
take DOS' non-re-entrant nature into account.  It is possible to detect
in your handlers when DOS is "safe" to be interrupted for disk I/O.
You will likely need to look to assembly for help here.  I would
recommend the article in Microsoft System Journal, v7n1.  It covers
TEMPLATE.ASM, a DOS-safe TSR by Douglas Boling.  Beware: I have
found MANY mistakes in the code.  However, it is STILL a source of much
good information.

Alternatively, you might consider a "save" function which is able to
save small portions of the data, based on parameters or static data
or something, then, say, in an idle loop while waiting for input, this
routine could be called to perform the save in parts.  This method, of
course, may not be feasible depending upon your program flow, etc.

-- Jon