... seems to be common in this context (in the sense of computers with/designed for fixed-line connections, as opposed to mobile devices such as smartphones or tablets).

See, for example,

http://ejlt.org/article/view/32/52
"1. Mobile Internet: Content and Control
...
These 2G networks delivered data at about 65% of the speed of the modems used for fixed-line computers circa 1994/5.
..."

http://www.global-partners.co.uk/wp-content/uploads/Horner-L...
"Even once these issues are addressed, the mobile internet should not be viewed as a substitute for fixed-line connectivity and computers. Fixed-line computers are better suited to internet activities that require large bandwidth and powerful data processing."

http://www.comscore.com/Insights/Blog/More_than_Snow_Fell_Ho...
"These data illustrate, once again, how mobile devices are become increasingly indispensable to people in times of emergencies, not just as a communication channel, but also as an alternative method of gathering information via the Internet when fixed line computers are unavailable."

http://www.dailymail.co.uk/debate/article-2191977/4G-hailed-...
"Will our smartphones finally rival fixed-line computers in terms of fast Internet access speeds?"