h1. HardwareRequirements

h2. Android versions 

|_. Android version |_. 4.2 |_. 6.0 |_. 9.0 |_. Notes |
|_. RAM | 340M[1] | 424M[2] | 512M[3] | It also depends on the display resolution and size:
On android 9, it can go up to 1824MB on 64bit ARM with very high dpi and resolutions |
|_. /data partition | | | 4 GB | It might also be possible to use external storage for that | 

fn1. "android-4.2-cdd.pdf":https://source.android.com/compatibility/4.2/android-4.2-cdd.pdf

fn2. "android-6.0-cdd.pdf":https://source.android.com/compatibility/6.0/android-6.0-cdd.pdf

fn3. "android-9-cdd.pdf":https://source.android.com/compatibility/9/android-9-cdd.pdf and "html version":https://source.android.com/compatibility/9/android-9-cdd.html#2_2_1_hardware

h2. Android 9.0 compatibility

|_. Device |_. RAM |_. Display |
|_. Samsung Galaxy SII (i9100) | OK:
* Has 1GB and an HDPI display[9]
* 512M required for "280dpi or lower on small/normal screens*":https://source.android.com/compatibility/9/android-9-cdd.html#2_2_1_hardware | HDPI[1]: 480x800 233 ppi[9] |
|_. Samsung Galaxy SIII (i9300) | OK:
* Has 1GB
* "608MB required for XDPI":https://source.android.com/compatibility/9/android-9-cdd.html#2_2_1_hardware |/2. XDPI[1]: 720×1280 306ppi[2] |
|_. Samsung Galaxy SIII 4G (i9305) | OK:
* Has 2GB
* "608MB required for XDPI":https://source.android.com/compatibility/9/android-9-cdd.html#2_2_1_hardware |
|_. Goldelico GTA04 A3 |/2. May be or may not be OK:
* The A3[4] and A4[5] have 512MB of RAM
* "608MB required for xdpi":https://source.android.com/compatibility/9/android-9-cdd.html#2_2_1_hardware but the resolution is very small |/3. XDPI[1]: 480×640 282ppi[2] |
|_. Goldelico GTA04 A4 |
|_. Goldelico GTA04 A5 | OK?:
* The A5[6] may have 1G of RAM
* "608MB required for xdpi":https://source.android.com/compatibility/9/android-9-cdd.html#2_2_1_hardware |
|_. LG Optimus black (p970) | OK:
* 512M
* "small screens with 280dpi or less":https://source.android.com/compatibility/9/android-9-cdd.html#2_2_1_hardware | HDPI[1]: 480×800 233ppi[3] |
|_. Amazon Kindle Fire first generation | OK:
* 512M[7]
* "mdpi or lower on large screens":https://source.android.com/compatibility/9/android-9-cdd.html#2_2_1_hardware | mdpi: 1024×600 at 169 ppi[8] |


fn1. https://en.wikipedia.org/wiki/Pixel_density#Named_pixel_densities

fn2. https://en.wikipedia.org/wiki/Galaxy_SIII

fn3. https://en.wikipedia.org/wiki/LG_Optimus_Black

fn4. http://projects.goldelico.com/p/gta04-main/downloads/get/GTA04A3-1-complete.pdf

fn5. http://projects.goldelico.com/p/gta04-main/downloads/get/GTA04A4-3_System_Manual_Complete.pdf

fn6. http://git.goldelico.com/?p=letux-uboot.git;a=blob;f=board/goldelico/letux-gta04/gta04.c;h=258b2be62904d98639a9a92afc2ede793685eb4c;hb=refs/heads/master#l228

fn7. https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm/boot/dts/omap4-kc1.dts#n16

fn8. https://en.wikipedia.org/wiki/Kindle_Fire

fn9. https://en.wikipedia.org/wiki/Galaxy_S

h2. Source code and configuration

Android can be configured to use less hardware resources. Here are some links on the topic:

* "Low RAM switch":https://github.com/LineageOS/android_frameworks_base/blob/22c9c67a32df0fa20dda27599151d05a6d9c2582/core/java/android/app/ActivityManager.java#L928 - ro.config.low_ram
* "Links to Android Go Optimizations that exist for AOSP 8 and AOSP 9":https://redmine.replicant.us/projects/replicant/wiki/PortingToAndroid9#Links (Some or all of these optimizations might be a bad trade off if they optimize RAM "at the expense of CPU power":https://android.googlesource.com/platform/build/+/master/target/product/go_defaults_common.mk#49 since the CPU in Replicant is used to render graphics)