Welcome to Acer Aspire One Hdd modding post, AAO 110 comes with only 1.8” SSD ZIF connecter, to increase the storage space, either you can purchase high capacity SSD (they are quite expensive) or install 1.8” PATA drive as shown by tnkgrl. Although while searching i also found a 1.8” to 2.5” IDE connecter here. AAO 110 comes with a SATA controller but you need to attach a sata connecter to AAO motherboard by soldering.
DISCLAIMER: You need a fine precision soldering skills to perform this mode, i recommend use of temperature controlled soldering station with 0.5 mm tip and flux, magnification is plus. i will not be a responsible of any damage of any kind, so try this at your own risk.
Place tape or insulating material between the HDD and PCB for safety.
For Sata connecter we need a MOLEX 47018-2001 connecter, with MOLEX 47018-4001, the gap between the Hdd and motherboard will be greater and cause some balance problems.
First fix the connecter to the PCB through double sided tape ( half part, which is slightly higher than the pins ), and start soldering, you need to solder all the data pins (1-7) and for power terminal pins (4,5,6)ground and pins (7,8,9 )5v must be connected rest you can leave as well. see here for complete pin outs description. Also short the r364 (mark as small yellow box in picture) to get the power to sata connecter. After soldering it would look like this.
you can also place a double sided type under the HDD to make it more stable and fix.
last but not the least, insert HDD….
Now you have to cut all the extra plastic screw holder on the base of your AAO to fit your Hdd. Now a bad news came, what ever you do, your AAO daughter board will not allow to fit HDD, see the picture…
i found no way to solve this, as a result right side of the AAO cover will not be perfect fit, you can see a slight gap. i am still looking to find some other alternative to Molex connecter. other than that HDD recognized by the bios.
I found a picture of AA0 150 motherboard, as you can see,it uses another connecter than Molex. any idea …
i try to install the Windows XP on AAO, but it was hell of a big problem, but i will keep it to another separate post.