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Merge pull request #12 from penfold42/switchdecode 

RAMBOard support - 8k ram @ $8000
This commit is contained in:
Stephen White 2018-05-30 20:29:14 +10:00 committed by GitHub
parent 59057a8d44 c7c3b0901c
commit d970e0ec73
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GPG Key ID: 4AEE18F83AFDEB23
3 changed files with 102 additions and 18 deletions
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111
src/main.cpp
View File

@ -90,6 +90,7 @@ u8 deviceID = 8;
IEC_Commands m_IEC_Commands;
bool onResetChangeToStartingFolder = false;
bool extraRAM = false;
bool enableRAMBOard = false;
bool disableSD2IECCommands = false;
bool supportUARTInput = false;
bool graphIEC = false;
@ -202,20 +203,43 @@ DWORD get_fattime() { return 0; } // If you have hardware RTC return a correct v
// 1c00 !cs2 on pin 7
u8 read6502(u16 address)
{
u8 value;
if (address & 0x8000) // address line 15 selects the ROM
u8 value = 0;
if (address & 0x8000)
{
value = roms.Read(address);
switch (address & 0xe000) // keep bits 15,14,13
{
case 0x8000: // 0x8000-0x9fff
if (enableRAMBOard) {
value = s_u8Memory[address]; // 74LS42 outputs low on pin 1 or pin 2
break;
}
case 0xa000: // 0xa000-0xbfff
case 0xc000: // 0xc000-0xdfff
case 0xe000: // 0xe000-0xffff
value = roms.Read(address);
break;
}
}
else
{
// Address lines 15, 12, 11 and 10 are fed into a 74LS42 for decoding
u16 addressLines15_12_11_10 = (address & 0x1c00) >> 10;
addressLines15_12_11_10 |= (address & 0x8000) >> (15 - 3);
if (addressLines15_12_11_10 == 0 || addressLines15_12_11_10 == 1) value = s_u8Memory[address & 0x7ff]; // 74LS42 outputs low on pin 1 or pin 2
else if (addressLines15_12_11_10 == 6) value = pi1541.VIA[0].Read(address); // 74LS42 outputs low on pin 7
else if (addressLines15_12_11_10 == 7) value = pi1541.VIA[1].Read(address); // 74LS42 outputs low on pin 9
else value = address >> 8; // Empty address bus
u16 addressLines12_11_10 = (address & 0x1c00) >> 10;
switch (addressLines12_11_10)
{
case 0:
case 1:
value = s_u8Memory[address & 0x7ff]; // 74LS42 outputs low on pin 1 or pin 2
break;
case 6:
value = pi1541.VIA[0].Read(address); // 74LS42 outputs low on pin 7
break;
case 7:
value = pi1541.VIA[1].Read(address); // 74LS42 outputs low on pin 9
break;
default:
value = address >> 8; // Empty address bus
break;
}
}
return value;
}
@ -258,12 +282,41 @@ u8 peek6502(u16 address)
void write6502(u16 address, const u8 value)
{
if (address & 0x8000) return; // address line 15 selects the ROM
u16 addressLines15_12_11_10 = (address & 0x1c00) >> 10;
addressLines15_12_11_10 |= (address & 0x8000) >> (15 - 3);
if (addressLines15_12_11_10 == 0 || addressLines15_12_11_10 == 1) s_u8Memory[address & 0x7ff] = value; // 74LS42 outputs low on pin 1 or pin 2
else if (addressLines15_12_11_10 == 6) pi1541.VIA[0].Write(address, value); // 74LS42 outputs low on pin 7
else if (addressLines15_12_11_10 == 7) pi1541.VIA[1].Write(address, value); // 74LS42 outputs low on pin 9
if (address & 0x8000)
{
switch (address & 0xe000) // keep bits 15,14,13
{
case 0x8000: // 0x8000-0x9fff
if (enableRAMBOard) {
s_u8Memory[address] = value; // 74LS42 outputs low on pin 1 or pin 2
break;
}
case 0xa000: // 0xa000-0xbfff
case 0xc000: // 0xc000-0xdfff
case 0xe000: // 0xe000-0xffff
return;
}
}
else
{
// Address lines 15, 12, 11 and 10 are fed into a 74LS42 for decoding
u16 addressLines12_11_10 = (address & 0x1c00) >> 10;
switch (addressLines12_11_10)
{
case 0:
case 1:
s_u8Memory[address & 0x7ff] = value; // 74LS42 outputs low on pin 1 or pin 2
break;
case 6:
pi1541.VIA[0].Write(address, value); // 74LS42 outputs low on pin 7
break;
case 7:
pi1541.VIA[1].Write(address, value); // 74LS42 outputs low on pin 9
break;
default:
break;
}
}
}
void write6502ExtraRAM(u16 address, const u8 value)
@ -963,6 +1016,9 @@ static void CheckOptions()
extraRAM = options.GetExtraRAM() != 0;
DEBUG_LOG("extraRAM = %d\r\n", extraRAM);
enableRAMBOard = options.GetRAMBOard() != 0;
DEBUG_LOG("RAMBOard = %d\r\n", enableRAMBOard);
disableSD2IECCommands = options.GetDisableSD2IECCommands();
//supportUARTInput = options.GetSupportUARTInput() != 0;
graphIEC = options.GraphIEC();
@ -978,6 +1034,23 @@ static void CheckOptions()
invertIECInputs = false;
ignoreReset = options.IgnoreReset();
// print confirmation of parsed options
if (0) {
screen.Clear(COLOUR_BLACK);
int y_pos = 200;
snprintf(tempBuffer, tempBufferSize, "ignoreReset = %d\r\n", ignoreReset);
screen.PrintText(false, 0, y_pos+=16, tempBuffer, COLOUR_WHITE, COLOUR_BLACK);
snprintf(tempBuffer, tempBufferSize, "RAMBOard = %d\r\n", enableRAMBOard);
screen.PrintText(false, 0, y_pos+=16, tempBuffer, COLOUR_WHITE, COLOUR_BLACK);
snprintf(tempBuffer, tempBufferSize, "splitIECLines = %d\r\n", splitIECLines);
screen.PrintText(false, 0, y_pos+=16, tempBuffer, COLOUR_WHITE, COLOUR_BLACK);
snprintf(tempBuffer, tempBufferSize, "invertIECInputs = %d\r\n", invertIECInputs);
screen.PrintText(false, 0, y_pos+=16, tempBuffer, COLOUR_WHITE, COLOUR_BLACK);
snprintf(tempBuffer, tempBufferSize, "invertIECOutputs = %d\r\n", invertIECOutputs);
screen.PrintText(false, 0, y_pos+=16, tempBuffer, COLOUR_WHITE, COLOUR_BLACK);
IEC_Bus::WaitMicroSeconds(5 * 1000000);
}
ROMName = options.GetRomFontName();
if (ROMName)
{
@ -1077,12 +1150,14 @@ extern "C"
write32(ARM_GPIO_GPCLR0, 0xFFFFFFFF);
DisplayLogo();
int y_pos = 184;
snprintf(tempBuffer, tempBufferSize, "Copyright(C) 2018 Stephen White");
screen.PrintText(false, 0, 200, tempBuffer, COLOUR_WHITE, COLOUR_BLACK);
screen.PrintText(false, 0, y_pos+=16, tempBuffer, COLOUR_WHITE, COLOUR_BLACK);
snprintf(tempBuffer, tempBufferSize, "This program comes with ABSOLUTELY NO WARRANTY.");
screen.PrintText(false, 0, 216, tempBuffer, COLOUR_WHITE, COLOUR_BLACK);
screen.PrintText(false, 0, y_pos+=16, tempBuffer, COLOUR_WHITE, COLOUR_BLACK);
snprintf(tempBuffer, tempBufferSize, "This is free software, and you are welcome to redistribute it.");
screen.PrintText(false, 0, 232, tempBuffer, COLOUR_WHITE, COLOUR_BLACK);
screen.PrintText(false, 0, y_pos+=16, tempBuffer, COLOUR_WHITE, COLOUR_BLACK);
if (!quickBoot)
IEC_Bus::WaitMicroSeconds(3 * 1000000);

7
src/options.cpp
View File

@ -122,6 +122,7 @@ Options::Options(void)
, deviceID(8)
, onResetChangeToStartingFolder(0)
, extraRAM(0)
, enableRAMBOard(0)
, disableSD2IECCommands(0)
, supportUARTInput(0)
, graphIEC(0)
@ -174,6 +175,12 @@ void Options::Process(char* buffer)
if ((nValue = GetDecimal(pValue)) != INVALID_VALUE)
extraRAM = nValue;
}
else if (strcasecmp(pOption, "RAMBOard") == 0)
{
unsigned nValue = 0;
if ((nValue = GetDecimal(pValue)) != INVALID_VALUE)
enableRAMBOard = nValue;
}
else if (strcasecmp(pOption, "DisableSD2IECCommands") == 0)
{
unsigned nValue = 0;

2
src/options.h
View File

@ -49,6 +49,7 @@ public:
const char* GetRomFontName() const { return ROMFontName; }
const char* GetRomName(int index) const;
unsigned int GetExtraRAM() const { return extraRAM; }
unsigned int GetRAMBOard() const { return enableRAMBOard; }
unsigned int GetDisableSD2IECCommands() const { return disableSD2IECCommands; }
unsigned int GetSupportUARTInput() const { return supportUARTInput; }
@ -70,6 +71,7 @@ private:
unsigned int deviceID;
unsigned int onResetChangeToStartingFolder;
unsigned int extraRAM;
unsigned int enableRAMBOard;
unsigned int disableSD2IECCommands;
unsigned int supportUARTInput;
unsigned int graphIEC;