andamiro: Add more MK5/V documentation

* Update general information about the mainboard taken
  from an actual MKV I own
* Add information about the hex codes showing on the 7
  segment display next to the mainboard breakout

andamiro/board.md

@@ -113,21 +113,9 @@ PC-DOCTOR DOS 3.0 Copyr 2004 PC-Doctor, Inc. 16:15 9/25/2000
 * [Pump it Up The Premiere 3: The International 3rd Dance Floor](game/piu/prem3.md)
 * [Pump it Up The PREX 3: The International 4th Dance Floor](game/piu/prex3.md)
 
-## MK5
+## MK5 / MKV
 
-* OS
+See [MKV](board/mkv.md).
-  * Windows XP Embedded: revisions of [The Premiere 3](game/piu/prem3.md) and [The PREX 3](game/piu/prex3.md)
-  * Linux: starting [Exceed](game/piu/exc.md)
-* [PIUIO](io.md#MK5IO) connected to the ISA bus
-* CPU: Intel Celeron 1 GHZ
-* RAM: 128 MB
-* GPU: on-board Riva TNT 2, 32 MB
-* Chipset: Nvidia NV11
-* Disk media
-  * CDROM based for [The Premiere 3](game/piu/prem3.md) and [The PREX 3](game/piu/prex3.md)
-  * DVD based for [Exceed](game/piu/exc.md) beta
-  * HDD based for [Exceed](game/piu/exc.md) release and newer
-* EEPROM to store game settings and high scores. Size increased (doubled?) comapred to [MK3](#mk-3)
 
 ### MK5 compatible games
 

andamiro/board/mkv.md

@@ -0,0 +1,112 @@
+# MKV
+
+AKA MK5
+
+* OS
+  * Windows XP Embedded: revisions of [The Premiere 3](game/piu/prem3.md) and [The PREX 3](game/piu/prex3.md)
+  * Linux: starting [Exceed](game/piu/exc.md)
+* [PIUIO](io.md#MK5IO) connected to the ISA bus
+* CPU
+  * Intel Celeron 1 GHZ
+  * Intel Celeron 1.3 GHZ
+* RAM: 128 MB
+* GPU (on-board)
+  * Riva TNT 2, 32 MB
+  * 
+* Chipset
+  * Nvidia NV11
+  * VIA Apollo Pro133 AX (VT82C694X + VIA686B)
+* BIOS
+  * PhoenixBIOS 4.0 Release 6.0 
+* Disk media
+  * CDROM based for [The Premiere 3](game/piu/prem3.md) and [The PREX 3](game/piu/prex3.md)
+  * DVD based for [Exceed](game/piu/exc.md) beta
+  * HDD based for [Exceed](game/piu/exc.md) release and newer
+* 7 segment display on the side shows current boot status/error codes
+* EEPROM to store game settings and high scores. Size increased (doubled?) comapred to [MK3](#mk-3)
+
+## 7 segment status and error codes
+
+This display next to the mainboard breakout connectors shows an 8-bit hex value indicating
+different stages of the boot process and errors.
+
+Errors are usually "stuck values". A healthy boot sequence has these numbers changing to show
+it progresses through the different stages
+
+### Healthy boot sequence
+
+The following is "transcribed" from a video recording of a healthy boot sequence (from power on
+to game title screen). All values are 8-bit hex values.
+
+* `FF`: Initial state shown right after power on
+* `81`: ???
+* `84`: ???
+* `85`: ???
+* `86`: ???
+* `87`: ???
+* `88`: ???
+* `08`: ???
+* `11`: ???
+* `0C`: ???
+* `28`: ???
+* `2E`: ???
+* `38`: ???
+* `09`: ???
+* `69`: ???
+* `49`: ???
+* `4A`: ???
+* `59`: ???
+* `52`: ???
+* `60`: Video output over VGA shows the Andamiro logo on white background, first actual video output
+  visible
+* `98`: ???
+* `6A`: ???
+* `00`: ???
+* `01`: ???
+* `C0`: ???
+* `D2`: ???
+* `00`-`99`/`00`: Progress counting upwards from 0 (`00`) to 100 (`00`)
+* `FF`: ???
+* `88`: ???
+* `FF`: ???
+* `88`: ???
+* `A2`: booted from HDD, starting with andamiro MKV bootloader stage and stays also when in-game
+
+### Operating system/game booted
+
+Once the display shows `A2`, it's also flickering.
+
+The bottom segment of the first digit as well as the top left and bottom right segments of the
+second digit are used as HDD, CPU and ??? indicators.
+
+### Other codes
+
+* `01`: In BIOS menu
+
+### Errors
+
+#### Stuck at FF right after power on
+
+If the BIOS isn't loading, then it is stuck right after power on.
+
+This might indicate that something is wrong with the power to the mainboard. Ensure you are using
+the power distribution board of the MKV box and not have a ATX power supply connected directly to
+the mainboard. It powers, but doesn't seem to like that and stays stuck here immediately.
+
+#### Stuck at C0
+
+Operating system not found.
+
+This should also be visible on over VGA output with a message stating this on a connected screen.
+
+#### Stuck on B0
+
+CMOS checksum bad.
+
+This should also be visible on over VGA output with a message stating this on a connected screen.
+
+Probably the CMOS battery is empty, swap it, power cycle. Defaults are being loaded automatically.
+
+## Misc
+
+* USB keyboards work, e.g. to get into the BIOS by pressing F2 during boot