Обратите внимание,что спрашивает диск
[root@localhost ~]# apt-get install qcad
Reading Package Lists... Done
Building Dependency Tree... Done
The following extra packages will be installed:
qt3-assistant
The following NEW packages will be installed:
qcad qt3-assistant
0 upgraded, 2 newly installed, 0 removed and 0 not upgraded.
Need to get 0B/4768kB of archives.
After unpacking 13.7MB of additional disk space will be used.
Do you want to continue? [Y/n] y
Media Change: Please insert the disc labeled
'ALT Linux 4.1.0 Desktop (Thymus) build 2008-10-06'
in the drive '/media/cdrom/' and press enter
Вам,что трудно его вставить?Ведь он есть в репозитории,зачем вам rpm пакет?