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Fix IEC drive timing

This commit is contained in:
drmortalwombat 2023-10-22 12:14:15 +02:00
parent 6e4bf52781
commit aad35e0243
2 changed files with 24 additions and 29 deletions
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50
include/c64/iecbus.c
View File

@ -14,14 +14,14 @@ IEC_STATUS iec_status;
#pragma optimize(push)
#pragma optimize(1)
// multiples of 5us
static void delay(char n)
{
while (n)
{
__asm {
nop
}
n--;
__asm {
ldx n
l1:
dex
bne l1
}
}
@ -70,7 +70,7 @@ static bool data_check(void)
return true;
else
{
iec_status = IEC_TIMEOUT;
iec_status = IEC_DATA_CHECK;
return false;
}
}
@ -81,7 +81,7 @@ bool iec_eoi(void)
while (!(cia2.pra & CIA2B_DATAIN))
;
delay(50);
delay(40);
return data_check();
}
@ -93,25 +93,21 @@ bool iec_write(char b)
while (!(cia2.pra & CIA2B_DATAIN))
;
clock_high();
for(char i=0; i<8; i++)
{
clock_high();
if (b & 1)
data_low();
else
data_high();
delay(5);
clock_low();
b >>= 1;
__asm
{
nop
nop
nop
nop
}
delay(5);
clock_high();
data_low();
}
data_low();
clock_high();
return data_check();
}
@ -131,13 +127,7 @@ char iec_read(void)
{
iec_status = IEC_EOF;
data_high();
__asm
{
nop
nop
nop
nop
}
delay(4);
data_low();
cnt = 200;
@ -172,10 +162,11 @@ char iec_read(void)
void iec_atn(char dev, char sec)
{
cdata_low();
atn_high();
clock_high();
delay(100);
delay(200);
iec_write(dev);
if (sec != 0xff)
@ -190,8 +181,10 @@ void iec_talk(char dev, char sec)
{
iec_status = IEC_OK;
iec_atn(dev | 0x40, sec);
iec_atn(dev | 0x40, sec | 0x60);
clock_low();
delay(10);
}
void iec_untalk(void)
@ -203,7 +196,7 @@ void iec_listen(char dev, char sec)
{
iec_status = IEC_OK;
iec_atn(dev | 0x20, sec);
iec_atn(dev | 0x20, sec | 0x60);
}
void iec_unlisten(void)
@ -216,6 +209,7 @@ void iec_open(char dev, char sec, const char * fname)
iec_status = IEC_OK;
iec_atn(dev | 0x20, sec | 0xf0);
char i = 0;
while (fname[i])
{

3
include/c64/iecbus.h
View File

@ -7,7 +7,8 @@ enum IEC_STATUS
IEC_EOF = 0x01,
IEC_ERROR = 0x80,
IEC_TIMEOUT
IEC_TIMEOUT,
IEC_DATA_CHECK
};
extern IEC_STATUS iec_status;