<Allison must be very brave.  Well, it is possible, but be sure to have
<your layout reviewed by a signal integrity geek (I'll volunteer) first,
<and try to build it using only the same old, slow parts that those
<historic two-layer boards were made with. (Remember, there are _reasons_
<why things weren't so reliable back then...)

If I had to comply with EMC it's scary.  For low and slow like a PIO 
qbus IDE a well designed and gridded 2 sided card would fly fine.  I've
done faster and nastier with double sided before 4layer stuff was 
considered affordable.  Besides the Q-bus is about right for LS/ALS
speed ttl.

In the past I've put DRV11Ps in micovaxen and that both twosided and 
wirearap.

If given a choice to do a 4 layer card I would though, it's easier to 
layout.

just remember the rules:  GOOD, FAST, CHEAP, pick two!

Allison