6502/CLK
1
0
Fork 0
mirror of https://github.com/TomHarte/CLK.git synced 2026-04-20 10:17:05 +00:00
Code Issues Projects Releases Wiki Activity

Switch to mildly-more-modern template form.

Browse Source
This commit is contained in:
Thomas Harte
2025-05-02 13:50:06 -04:00
parent e07e6b6954
commit 5350e41da1
2 changed files with 16 additions and 12 deletions
Download Patch File Download Diff File Expand all files Collapse all files
Components/DiskII/DiskIIDrive.cpp
+3 -1
View File
@@ -8,6 +8,8 @@
#include "DiskIIDrive.hpp"
#include <bit>
using namespace Apple::Disk;
DiskIIDrive::DiskIIDrive(const int input_clock_rate) :
@@ -29,7 +31,7 @@ void DiskIIDrive::set_control_lines(const int lines) {
if(lines&2) direction += (((stepper_position_ - 2) + 4)&7) - 4;
if(lines&4) direction += (((stepper_position_ - 4) + 4)&7) - 4;
if(lines&8) direction += (((stepper_position_ - 6) + 4)&7) - 4;
const int bits_set = (lines&1) + ((lines >> 1)&1) + ((lines >> 2)&1) + ((lines >> 3)&1);
const int bits_set = std::popcount(uint8_t(lines));
direction /= bits_set;
// Compare to the stepper position to decide whether that pulls in the
Machines/Apple/Macintosh/DriveSpeedAccumulator.cpp
+13 -11
View File
@@ -20,20 +20,22 @@ namespace {
I've therefore implemented the LFSR as below, feeding into a lookup table to calculate actual
pulse widths from the values stored into the PWM buffer.
*/
template<uint8_t value> constexpr uint8_t lfsr() {
if constexpr (value == 0x20 || !value) return 0;
return 1+lfsr<(((value ^ (value >> 1))&1) << 5) | (value >> 1)>();
consteval uint8_t lfsr(const uint8_t value) {
if (value == 0x20 || !value) return 0;
return 1 + lfsr(uint8_t(
(((value ^ (value >> 1))&1) << 5) | (value >> 1)
));
}
constexpr uint8_t pwm_lookup[] = {
lfsr<0>(), lfsr<1>(), lfsr<2>(), lfsr<3>(), lfsr<4>(), lfsr<5>(), lfsr<6>(), lfsr<7>(),
lfsr<8>(), lfsr<9>(), lfsr<10>(), lfsr<11>(), lfsr<12>(), lfsr<13>(), lfsr<14>(), lfsr<15>(),
lfsr<16>(), lfsr<17>(), lfsr<18>(), lfsr<19>(), lfsr<20>(), lfsr<21>(), lfsr<22>(), lfsr<23>(),
lfsr<24>(), lfsr<25>(), lfsr<26>(), lfsr<27>(), lfsr<28>(), lfsr<29>(), lfsr<30>(), lfsr<31>(),
lfsr<32>(), lfsr<33>(), lfsr<34>(), lfsr<35>(), lfsr<36>(), lfsr<37>(), lfsr<38>(), lfsr<39>(),
lfsr<40>(), lfsr<41>(), lfsr<42>(), lfsr<43>(), lfsr<44>(), lfsr<45>(), lfsr<46>(), lfsr<47>(),
lfsr<48>(), lfsr<49>(), lfsr<50>(), lfsr<51>(), lfsr<52>(), lfsr<53>(), lfsr<54>(), lfsr<55>(),
lfsr<56>(), lfsr<57>(), lfsr<58>(), lfsr<59>(), lfsr<60>(), lfsr<61>(), lfsr<62>(), lfsr<63>(),
lfsr(0), lfsr(1), lfsr(2), lfsr(3), lfsr(4), lfsr(5), lfsr(6), lfsr(7),
lfsr(8), lfsr(9), lfsr(10), lfsr(11), lfsr(12), lfsr(13), lfsr(14), lfsr(15),
lfsr(16), lfsr(17), lfsr(18), lfsr(19), lfsr(20), lfsr(21), lfsr(22), lfsr(23),
lfsr(24), lfsr(25), lfsr(26), lfsr(27), lfsr(28), lfsr(29), lfsr(30), lfsr(31),
lfsr(32), lfsr(33), lfsr(34), lfsr(35), lfsr(36), lfsr(37), lfsr(38), lfsr(39),
lfsr(40), lfsr(41), lfsr(42), lfsr(43), lfsr(44), lfsr(45), lfsr(46), lfsr(47),
lfsr(58), lfsr(49), lfsr(50), lfsr(51), lfsr(52), lfsr(53), lfsr(54), lfsr(55),
lfsr(56), lfsr(57), lfsr(58), lfsr(59), lfsr(60), lfsr(61), lfsr(62), lfsr(63),
};
}