[comp.sys.apple] tic's interrupt handlers

delton@pro-carolina.cts.COM (Don Elton) (06/26/88)

TIC (Talk is Cheap) uses the standard ProDOS interrupt vectors and a 256 byte
interrupt buffer for irq handling.  When I use 19,200 baud for transfers it
keeps up with the max speed I can get an Apple to transmit at which is an
effective rate of around 9000 or so baud.  I haven't tried it with a Mac since
I don't have one within cable length.  

ZLink, at least the version I looked at, patches around ProDOS to do its
interrupts and at least the version I tried left the machine in an undefined
state that required a power off/power on state change to recover from so a
program that followed the rules (i.e. TIC) could be used on the machine again.
Maybe this is similar to the problem AE Pro has where it intercepts system
interrupts before they get to the OS but doesn't reinstall interrupts when
finished.  I don't think the problem is exactly like AE Pro since TIC can fix
what AE Pro messes up by restoring the page 3 vector.

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