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Update c64krvsw.ino
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Completely removed keyboard scanning resets and RESTORE key long hold for RESET. The "timeout" scans were interfereing (not working) with cartridges.
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@1stage
1stage committed Jan 28, 2020
1 parent 59e355d commit 21a33f0
Showing 1 changed file with 6 additions and 73 deletions.
79 changes: 6 additions & 73 deletions Arduino/c64krvsw/c64krvsw.ino
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Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
#include <EEPROM.h>

// C64 KRV (Kernal ROM Video) Switcher
// v1.1 by Sean Harrington
// v1.2 by Sean Harrington
// Original design by Sven Petersen
// EXROM code from Adrian Black
//
Expand Down Expand Up @@ -48,6 +48,8 @@
// ensure the system will reset in the event a bad Kernal image is loaded. If this is undesireble,
// mode 0 is used to ignore the lack of keyboard scan.
//
// v1.2, 31 JAN 2020 - Removed keyboard scanning protection so make sure ALL your KERNEL images work before deploying!
// Removed long RESTORE key hold for RESET
// v1.1, 04 NOV 2019 - Rewrote number key processing routine as switch/case statement
// Reworked boolean variables to evaluate themselves rather than using == comparators
// Fixed main() loop key and RESTORE scan routines for sanity sake
Expand Down Expand Up @@ -86,22 +88,15 @@ const int Col7 = A4; // Input, colu
const int RESTOREPin = A5; // Input, RESTORE key, active low
const int KMax = 8; // Holds the highest Kernal number
const int KernalSlot = 0; // Kernal selection address in EEPROM
const int ScanActiveSlot = 1; // Keyscan active address in EEPROM
const int NPModeSlot = 2; // NTSC/PAL mode address in EEPROM
const int Default_Scan_Count = 10000; // Delay in milliseconds before reset for no scan activity
const int Default_Restore_Count = 5000; // Delay in milliseconds for RESTORE key hold before reset

// *** Variables ***
// *** Variables ***
byte kernal_num = 0; // Kernal number
byte kernal_addr = 0; // Address bits for Kernal, always kernal_num - 1
byte np_mode = 1; // Default NTSC/PAL mode, 1 is NTSC, 0 is PAL
bool restore_found = false; // TRUE if the RESTORE key is pressed
int restore_counter = 0; // Countdown for RESTORE key
byte key = 128; // Calculate the Key
byte columns; // Variable for reading out the column
int scan_counter; // Countdown for keyboard scanning
bool scan_found; // Flag for keyboard activity detected
byte scan_active = 1; // Default keyboard scan active, 1 is on

// *** Data Exchange variables for ISR (have to be volatile) ***
volatile bool numPressed = false; // ISR flag for number pressed
Expand Down Expand Up @@ -133,13 +128,8 @@ void setup() { // Keyboard sc
EEPROM.write(KernalSlot, kernal_num);
}

kernal_addr = kernal_num - 1; // Calculate the address bits. It should be between 0 and 7,
kernal_addr = kernal_num - 1; // Calculate the address bits. It should be between 0 and 7

scan_active = EEPROM.read(ScanActiveSlot);
if ((scan_active != 0) && (scan_active != 1)) {
scan_active = 1;
EEPROM.write(ScanActiveSlot, scan_active);
}
// Last NTSC/PAL mode read from EEPROM
np_mode = EEPROM.read(NPModeSlot); // Read the Video Mode from EEPROM
if ((np_mode != 0) && (np_mode != 1)) { // If out of range,
Expand All @@ -151,13 +141,6 @@ void setup() { // Keyboard sc
// Switch the KERNAL and Video Mode
SetAddressBits( kernal_addr ); // Set the MS address bits for the Kernal ROM
SetVideoBits ( np_mode ); // Set the video address bits

scan_counter = Default_Scan_Count; // Reset scan countdown
scan_found = false; // Reset detection flag

if (scan_active == 0) { // If keyboard scanning is INACTIVE,
scan_found = true; // set scan_found to TRUE.
}

attachInterrupt(digitalPinToInterrupt(Row0), ISR_Row0, LOW);
attachInterrupt(digitalPinToInterrupt(Row3), ISR_Row3, LOW);
Expand Down Expand Up @@ -229,12 +212,6 @@ void SwitchKernal() {
delay( 2000 ); // Wait for two seconds
systemUNRESET(); // Remove system from RESET mode
delay( 2000 ); // Wait another two seconds
scan_counter = Default_Scan_Count; // Reset scan countdown
if (scan_active == 1) { // If we're checking for scan activity...
scan_found = false; // ...reset detection flag
} else { // Otherwise we're NOT checking for scan activity...
scan_found = true; // Set scan found to true
}
}

// *** Switch video mode function ***
Expand All @@ -244,19 +221,12 @@ void SwitchVideo() {
delay( 2000 ); // Wait two seconds
systemUNRESET(); // Remove system from RESET mode
delay( 2000 ); // Wait another two seconds
scan_counter = Default_Scan_Count; // Reset scan countdown
if (scan_active == 1) { // If we're checking for scan activity...
scan_found = false; // ...reset detection flag
} else { // Otherwise we're NOT checking for scan activity...
scan_found = true; // Set scan found to true
}
}

// *** Interrupt Service Routine for Row0 ***
void ISR_Row0() {
if (!numPressed) { // Only process info after the flag was reset by main routine
colData = PINC & 0x1F; // Read the columns from Port C input pins register AND 0x1F
scan_found = true; // Any activity here indicates a working Kernal
numOdd = true; // Tell system Row0 has the odd numbers
if ((colData != 0x1F) && (colData !=0)) { // Only set the flag when a number is pressed
numPressed = true;
Expand All @@ -268,7 +238,6 @@ void ISR_Row0() {
void ISR_Row3 () {
if (!numPressed) { // Only process info after the flag was reset by main routine
colData = PINC & 0x1F; // Read the columns from Port C input pins register AND 0x1F
scan_found = true; // Any activity here indicates a working Kernal
numOdd = false; // Tell system Row3 has the even numbers
if ((colData != 0x1F) && (colData !=0)) { // Only set the flag when a number is pressed
numPressed = true;
Expand All @@ -278,44 +247,12 @@ void ISR_Row3 () {

// *** Main program loop ***
void loop() {

if (!scan_found) { // If previous scan activity was NOT detected...
columns = PINC & 0x1F; // ...read the columns from Port C input pins register AND 0x1F
if ((columns != 0x1F)) { // If any NEW activity found...
scan_found = true; // ...set flag.
} else { // Otherwise NEW scan activity was NOT detected...
if (scan_counter > 0) { // ...If the count down has NOT elapsed...
scan_counter--; // ......then decrement...
delayMicroseconds( 33 ); // ......and wait 33 microseconds
} else { // ...Otherwise the count down HAS elapsed...
if (scan_active == 1) { // ......If we ARE scanning
kernal_num = 1; // .........set Kernal Number 1 (it is assumed that this is not empty)
EEPROM.write(KernalSlot, kernal_num); // .........and save in EEPROM
kernal_addr = kernal_num - 1; // .........calculate the address bits
SwitchKernal(); // .........and switch kernal and reset C64
} else { // ......Otherwise (we are not scanning)
scan_counter = Default_Scan_Count; // .........Reset scan countdown (because it has elapsed!)
scan_found = true; // .........and fake the scanner into thinking we're good (because we're not scanning)
}
}
}
}


// *** Process RESTORE key ***
if (digitalRead( RESTOREPin ) == HIGH) { // If RESTORE reading is HIGH...
restore_found = false; // ...the RESTORE key is not pressed
restore_counter = Default_Restore_Count; // ...so reset the RESTORE count down
} else { // Otherwise the RESTORE reading is LOW...
restore_found = true; // ...and the RESTORE key is pressed,
if (restore_counter > 0) { // ...make sure countdown hasn't expired
restore_counter--; // ...and count down
} else { // ...Otherwise the RESTORE count down has elapsed...
systemRESET(); // ......so put system into RESET mode
scan_counter = Default_Scan_Count; // ......reset scan countdown
scan_found = false; // ......reset detection flag
delay( 2000 ); // ......and wait for two seconds
systemUNRESET(); // ......then remove system from RESET mode
}
}

// *** Process when a NUMBER key is pressed (set by ISR) ***
Expand All @@ -333,19 +270,15 @@ void loop() {
if ((restore_found) && (key >= 0) && (key <= 9)) { // RESTORE + number key pressed (0 - 9)
switch (key) {
default: // Keys 1 - 8: Switch to ROM number 1 - 8
scan_active = 1; // Every valid Kernal enters ACTIVE state
kernal_num = key; // Get Kernal Number
EEPROM.write(KernalSlot, kernal_num); // Write Kernal number to the EEPROM
kernal_addr = kernal_num - 1; // Calculate the address bits. It should be between 0 and 7,
EEPROM.write(ScanActiveSlot, scan_active); // Write scan status to EEPROM
SwitchKernal(); // Switch Kernal Number (also resets C64)
break; // --- Exit this case ---
case 0: // Key 0: Switch to ROM 1 and turn of keyboard scanning (cartridges sometimes need this)
scan_active = 0; // Turn scan off
kernal_num = 1; // Switch to KERNAL 1 (known good CBM v3 KERNAL)
EEPROM.write(KernalSlot, kernal_num); // Write Kernal number to the EEPROM
kernal_addr = kernal_num - 1; // Calculate the address bits. It should be between 0 and 7,
EEPROM.write(ScanActiveSlot, scan_active); // Write scan status to EEPROM
SwitchKernal(); // Switch Kernal Number (also resets C64)
break; // --- Exit this case ---
case 9: // Key 9: Switch video modes
Expand Down

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