[[Image:Dobbertin.gif|thumb|Dobbertin Logo]]
A harddisc manufactured by the German company [[Dobbertin|Dobbertin Industrie-Elektronik]].
One of the first ways to connect a Harddisc to the CPC.
*[[Prowort]] via using Dobbertin CP/M Plus (partitions D, E, F and G)
*[[X-DDOS|X-DDOS]] (v2.10)
*[[Z3Plus]] and [[NZ-COM]](providing hundreds of additional applications)*'-HD20BackUp' to backup / compare / restore the complete 20 MB hard disc* In addition a lot of (cracked) games are able to run from the HD-20 hard disc
== Technical ==
There is an expansion port interface which connects to the CPC.
It contains a 16KB ROM containing XD[[X-DOS DDOS]] which is normally in slot 6 but can be configured between 1 and 7.
There is a CPC interface which connects to a PC-XT interface.
The command descriptions and operation appear to be the same although the software seems to only use TEST READY, READ, WRITE, SEEK (parking), SET PARAMETERS and FORMAT.
Uses [[XDX-DOSDDOS]] v2.10 (which supports the harddisc20 MB hard-disc, and additionally supports external double sided 80 track disc drives).
The 20 MB harddisc hard-disc is split into four partitions, with drive names D, E, F, and G (drive name C isn't used here, but may be used as RAM disc, in combination with Dobbertin RAM expansion).
Under [[FutureOS]] the four partitions are named I, J, K and L. They can be accessed at the same time, so all 20 MB are usable at the same time.
These are real hardware values!
== Emulation ==
The Dobbertin HD20 is emulated by the Symbiface III since 7/2023. Therefore you need a subfolder 'HD20' on the USB stick. It needs to contain the 21 MB hard-disc image file.
It is also [https://www.cpcwiki.eu/forum/emulators/got-bored-again/ emulated in MAME since 6/2015]
== Other harddisc solutions for the CPC ==
Modern:
* [[M4 Board]] (IDE)* [[Albireo]] (IDESD card)
* [[CPC-IDE]] (IDE)
* [[HDCPC]] (IDE)
* [[IDE8255]] (IDE)
* [[M4 Board]] (SD card)
* [[SYMBiFACE II]] (IDE)
* [[SYMBiFACE III]] (USB, SD card)
* [[X-MASS]] (IDE)