Not necessaryly, Depending on how old the computer is, there might be a BIOS limit to how much it can read.
But in this case he is in LBA or ECHS mode, since 19 GB is larger then both the older limits.
Older computers used either of these 2 Modes.
CHS mode- only see drives up to 504 MB
Int 13h- Only see drives up to 7.88 GB
Now newer BIOS use a new mode called LBA or ECHS which allow up to 137 GB
Much newer BIOS's use a mode that can recongize up to 144 PetaBytes, But I forgot the name.
Also, there is no 80 pin connector, they are only 40 pins, but there are 80 conductors within the ribbon cable, for any Drive faster then ATA 33, you must use a 40 pin/ 80 conductor ribbon cable.