Those Disk Drives are not the original Amstrad standard.
Yet they were far more cheap and are nowadays easier to use.
Especially the 3½" (3"1/2 ?) as those disk are still availlable in some retailers. You can also easily find such drives in any garbage if you properly scavenge old rusty computers.
Those Disk size couldn't be side switched manually. The older models where using only one side (360 Ko ?) By double side (DD) or even High Density where available.
Formats
3"1/2
- DD = 720ko
- HD : 1,44 Mo
5"1/4
- er...I don't remember (editors please ?)
- 1,2 Mo was the maximum...on my old PC...
Beware : HD
Nowaday, only HD 3"1/2 disk can be found at good old retailer's.
But or beloved CPC can't understand easily the concept of High Density Disk with 1,44Mo avalaible...
So you have to cheat : just put some duct-tape (scotch-tape, whatever...) on the HD Hole. Tada, a proper DD disk with 720 Ko if your OS allows it. Or a common 2x180Ko (2x 178Ko ?) with firmware Loco Basic, if you have a manual side switcher button too of course).
PC users used to do the opposite : file a HD hole on DD disk...this worked well sometimes.
A clever choice
A great advantage at the time (in the 80's) was to get access to CP/M sofware library, as most of those were on such Disk.
Also, the Disk were far cheaper than the exotic 3", but...few CPC users actually got such drives.
Mostly professionnal users...The common snotling Gamer couldn't even dream of this...until nowadays.
As the magnetic disk is bigger...well the format is bigger too. It is common to get 720Ko disk (using the 2 sides, so 80 tracks)
Many Modern CPC users replace their old 3" by an external 3"1/2, adding a Disk drive A-B / B-A switcher (allowing to use the external disk Drive as if it were the internal one = Drive A).
Also a side switcher allows to use a 3"1/2 disk like a 3" disk... switching manually the sides as needed by good old 3" disk drives (yet a decent sofware can do it).
Softwares released on 3"1/2 disk
This pure awsomness even use a full DD disk's 80 tracks with more than 700Ko of Data, yet you have to get a proper DD disk Drive, as some older models may lack this feature...
Non 3" CPC disk drives
- Data Media Disc System
- Jasmin AM5D 5 "1/4 floppy drive
- KDS 5¼" Disc Drive (KDS Electronics)
- Vortex Disc Drives (Vortex)
- any scavenged rusty junk may be good enough nowaday, if you have a 664 or 6128...