Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!pasteur!agate!ucbvax!hplabs!hpfcdc!hpgrla!paulc
From: paulc@hpgrla.HP.COM (@Paul Charlton)
Newsgroups: comp.sys.ti
Subject: Re: Hacking with a TI99/4A
Message-ID: <10290001@hpgrla.HP.COM>
Date: 7 Feb 89 16:40:52 GMT
References: <55@umvlsi.ECS.UMASS.EDU>
Organization: Hewlett-Packard, Greeley, CO
Lines: 18

>I have a TI99/4A that I would like to get some use out of.  Has anyone
>out there ever used one for a non-standard purpose?  Such as burgular
>alarm, house control, etc?  Is there a way to software control one of
>the output pins on the side of the computer?  Any ideas are welcome!
>
>                            Thanks, Mik Killoran

as a minimum, you have to have assembly language support, BASIC won't do it.  
A "mini-memory" cartridge has the basic prerequisites for an un-expanded TI
system.  The port on the side of the computer has a full address and 
data bus, so memory mapped devices are pretty easy to control.
Other possibilities (if you only need a few control lines) are to 
control the cassette port or joystick port (each has two output pins)
 
 PaulC

 mail me at:
 { paulc@hpgrai.hp.com } | { hplabs!hpgrai!paulc }