using TWO Sanyo LB1641 Bidirectional motor drivers to drive bipolar stepper?

[dentaku]

I have these two old Sanyo LB1641 Bidirectional motor drivers I found somewhere. http://pdf.datasheetcatalog.com/datasheet/sanyo/ds_pdf_e/LB1641.pdf
I was wondering if it would be possible to drive a 4 wire Bipolar stepper motor using TWO of these to create the correct sequence (one for each winding).

I tested them both and they can run a little DC motor in both directions depending on which of the two IN pins is high and low. I know everyone uses the L297 or something similar but I just though this was in interesting experiment.

question regarding the datasheet: On page two it says...
Input level
1 : 2.0V or greater
0 : 0.7V or less
That's fine, I'm assuming that IN1 and IN2 register a HIGH if you give them 2V or higher and LOW if lower than 0.7V.

QUESTION: What tells me the maximum voltage and current that IN1 and IN2 (pins 5 and 6) can withstand?