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boards:sbc:sbc_v2:start [2019/10/12 03:15]
b1ackmai1er [Boot BEEP modification]
boards:sbc:sbc_v2:start [2020/01/28 07:05] (current)
b1ackmai1er [Recovery mode switch modification:]
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 </​code>​ </​code>​
  
-{{https://​www.retrobrewcomputers.org/​lib/​exe/​fetch.php?​media=boards:​sbc:​sbc_v2:​sbc-v2-003-speedmoddemo.gif?​linkonly|Demonstration video}}+{{https://​retrobrewcomputers.org/​lib/​exe/​fetch.php?​tok=ed17f7&​media=https://​www.retrobrewcomputers.org/​lib/​exe/​fetch.php?​media=boards:​sbc:​sbc_v2:​sbc-v2-003-speedmoddemo.gif?​linkonly|Demonstration video}} 
 + 
 +===== Recovery mode switch modification:​ ===== 
 + 
 +In some situations, reflashing a new ROMWBW image may result in an inaccessible system. This may happen when conflicts occur due to enabling additional ROMWBW features, when additional drivers are selected or during development. 
 + 
 +A basic recovery mode process can be activated, so that the minimum driver set is activated on boot. This is achieved by activating the BT_REC_TYPE option in your custom configuration. When activated ROMWBW will check an input at boot time to see if the recovery mode should be activated. A number of options can be selected to define what this input is. 
 + 
 +Example: 
 + 
 +SBC_std_cust.asm 
 + 
 +<​code>​ 
 +BT_REC_TYPE ​   .SET    BT_REC_SBC1B ​   ; CHECK 1-BIT IO PORT 
 +</​code>​ 
 + 
 +Boot recover input options: 
 + 
 +<​code>​ 
 +BT_REC_NONE ​     NO RECOVERY MODE 
 +BT_REC_FORCE ​    FORCE BOOT RECOVERY MODE 
 +BT_REC_SBC01 ​    BIT 1 RTC HIGH 
 +BT_REC_SBC1B ​    1-BIT IO PORT 
 +BT_REC_SBCRI ​    16550 UART RING INDICATOR LINE 
 +</​code>​ 
 + 
 +BT_REC+SBC1B utilized the existing 1-BIT IO jumper header on the SBC-V2. Connecting a push buttons switch to this header is all that is required. However, this will override the CRTACT option if that is in use. The following two options use other inputs that do not interfere with existing setting but require modification to the board 
 + 
 +BT_REC_SBC01 uses the RTC data line and requires soldering a push button switch to GND and RTC clock data line. 
 + 
 +BT_REC_SBCRI used the unused 16550 UART Ring Indicator line as an input. A more complex modification required. The ring indicator pin needs to be lifted out of the socket and a resistor and push button switch wired in.
  
  
boards/sbc/sbc_v2/start.1570864528.txt.gz · Last modified: 2019/10/12 03:15 by b1ackmai1er
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