Merge pull request acemielektron#15 from ikonko/main

Schematic update and clarification

images/ikonko/README.md

@@ -0,0 +1,56 @@
+**Schematic legend:**
+
+All resistors without a value represent an option, usually it's an SMD variation of a "jumper", so you can short it by wire or use the resistor with 0 Ohm value
+
+Power options:
+|Part | Behaviour |
+|-----|-----|
+| RW1 | 5V external power supply on leftmost pin of a floppy connector |
+| RW2 | Unkown voltage on +5V pin on leftmost pin of a floppy connector  |
+| NC  | Arduino power plug will be used instead of floppy connector |
+
+OLED display options:
+|Part | Behaviour |
+|-----|-----|
+| RO1 | 3V3 Power |
+| RO2 | 5V Power |
+| RO3 + RO4 | pinout: GND, Vcc, SDA, SCL (default for most displays)|
+| RO5 + RO6 | pinout: Vcc, GND, SDA, SCL |
+
+Drive select and motor on options:
+|Part | Behaviour |
+|-----|-----|
+| R10 - R16 | Connect D5 pin to respective input from FDC side |
+| R110 - R116 | Connect D4 pin to respective input from FDC side |
+
+Default PC config (crossed cable): 
+* single drive R12 + R116
+* dual drive:  R12 + R114
+
+Default Shugart config (straight cable):
+* single drive R10 + R116
+* dual drive:  R10 + R112
+
+FDC Grounding:
+|Part | Behaviour |
+|-----|-----|
+| RG1 | If short GND on pins 1-3, 7-33, if NC then GND on 21-33 pins only|
+
+Serial options:
+|Part | Behaviour |
+|-----|-----|
+| RX1 | RxD input resistor |
+| RX2 | RxD pull-down resistor (only if voltage divider is used) or ESD can be used if desired|
+| RT1 | TxD output resistor - usually short|
+| RT2 | TxD pull-down resistor - usually NC |
+
+![fddEMU_Schematic](fddEMU_schematic_v1.png)
+
+
+Additional notes:
+* **RP**x resistors are 1k pullups
+* Push button **S1** is put to the side of the board and can be omitted, as not really needed by firmware
+* SD module connector is split because of the stacked config of multiple interconnected PCBs, `/CS` signal must be connected with additional wire
+* **PCB in prototype stage! Not tested yet**
+
+![fddEMU_PCB](fddEMU_v1.png)

src/FloppyDrive.cpp

@@ -169,7 +169,7 @@ int FloppyDrive::getSectorData(int lba)
   uint8_t head   = 0;
   uint8_t track  = lba / (numSec*2);
   uint8_t sector = lba % (numSec*2);
-  if( sector >= numSec ) { head = 1; sector -= numSec; Serial.write('#'); }
+  if( sector >= numSec ) { head = 1; sector -= numSec; }
 
   Serial.write('R');
   Serial.printDEC(track);