scot101:
In my haste to follow your last instruction I left the 'enable' wire disconnected from theAttiny48ATtiny84. The L293D needs Enable 1 (pulsing to control speed) and either OUTPUT 1 or 2 HIGH to drive the motor.
Search the internet for "floating digital input" or this forum for "floating pin"...
https://www.google.com/search?q="floating"+pin+"digitalRead"+site:arduino.cc%2Fforum
Another way to look at it: The datasheet indicates enable (EN) must be driven LOW or HIGH. Anything else is then undefined. Which means the behaviour of the L293D is undefined.