Size Modifiers for Computers?

[ehrbar]

I was trying to figure out the costs for Awaken Computer (directly and as an enchantment), and that spell, as a Regular spell, interacts with the Size Modifier rules.

So, looking at the sizes in Ultra-Tech and High-Tech:

• The personal (Ultra-Tech, p.22) or medium (High-Tech, p.20) computer and smaller seem to be pretty obviously SM 0 or less.
• The microframe is "cabinet-sized" -- how big a cabinet, and is it a box or an elongated box or what? I'm imagining anything from SM +0 to maybe SM +3 could be justified here.
• The mainframe is not given a comparative size; the weight (400 lbs.) is ten times the weight of a microframe.
• The macroframe similarly is not given is not given a comparative size; the weight (4,000 lbs.) ten times the weight of a mainframe or a hundred times that of a microframe.
• The megacomputer is "the size of an entire building" (Ultra-Tech) or "fills a whole building or a series of subbasements". Its weight is given as 20 tons (ten times the macroframe, a hundred times the mainframe, a thousand times a microframe).

Is this nailed down any more precisely anywhere else?