Slackware still uses a text installation and manual partitioning is needed before the setup is started.
I’ve recorded a screencast about Slackware installation as it’s quite “non standard” and it requires more advanced Linux skills.
The video is about partitioning the HDD using the command line utility fdisk and partition configuration during the installation.
The screencast is hosted on vimeo in HD quality (the original source file is in AVI format and it’s available for download for registered vimeo users).
More on Slackware soon.