From 1aa6c47f8ef49ae5feb5f2e9c5caed0b99d1c54b Mon Sep 17 00:00:00 2001
From: folkert van heusden <mail@vanheusden.com>
Date: Thu, 18 Apr 2024 08:46:27 +0200
Subject: [PATCH] code clean-up
---
rl02.cpp | 76 ++++++++++++++++++++++++++++++++++++++++++--------------
rl02.h | 13 +++++++---
2 files changed, 68 insertions(+), 21 deletions(-)
diff --git a/rl02.cpp b/rl02.cpp
index e878a29..89aead2 100644
--- a/rl02.cpp
+++ b/rl02.cpp
@@ -1,4 +1,4 @@
-// (C) 2018-2023 by Folkert van Heusden
+// (C) 2018-2024 by Folkert van Heusden
// Released under MIT license
#include <errno.h>
@@ -13,9 +13,6 @@
#include "utils.h"
-constexpr int sectors_per_track = 40;
-constexpr int bytes_per_sector = 256;
-
static const char * const regnames[] = {
"control status",
"bus address ",
@@ -43,6 +40,10 @@ void rl02::reset()
{
memset(registers, 0x00, sizeof registers);
memset(xfer_buffer, 0x00, sizeof xfer_buffer);
+
+ track = 0;
+ head = 0;
+ sector = 0;
}
uint8_t rl02::readByte(const uint16_t addr)
@@ -102,13 +103,9 @@ void rl02::update_bus_address(const uint32_t a)
registers[(RL02_CSR - RL02_BASE) / 2] |= ((a >> 16) & 3) << 4;
}
-uint32_t rl02::calcOffset(const uint16_t da) const
+uint32_t rl02::calcOffset() const
{
- int sector = da & 63;
- int track = (da >> 6) & 1023;
- uint32_t offset = (sectors_per_track * track + sector) * bytes_per_sector;
-
- return offset;
+ return (rl02_sectors_per_track * track * 2 + head * rl02_sectors_per_track + sector) * rl02_bytes_per_sector;
}
void rl02::writeWord(const uint16_t addr, uint16_t v)
@@ -126,22 +123,49 @@ void rl02::writeWord(const uint16_t addr, uint16_t v)
DOLOG(debug, false, "RL02 set command %d, exec: %d", command, do_exec);
- uint32_t disk_offset = calcOffset(registers[(RL02_DAR - RL02_BASE) / 2] & ~1);
- int device = 0; // TODO
+ int device = 0; // TODO
+
+ bool do_int = false;
+
+ *disk_read_acitivity = true;
if (command == 2) { // get status
registers[(RL02_MPR - RL02_BASE) / 2] = 0;
}
- else if (command == 6 || command == 7) { // read data / read data without header check
- *disk_read_acitivity = true;
+ else if (command == 3) { // seek
+ uint16_t temp = registers[(RL02_DAR - RL02_BASE) / 2];
- uint32_t temp_disk_offset = disk_offset;
+ int cylinder_count = (((temp >> 7) & 255) + 1) * (temp & 4 ? 1 : -1);
+
+ int32_t new_track = 0; // when bit 4 is set, a reset is performed
+
+ if ((temp & 8) == 0) {
+ new_track = track + cylinder_count;
+
+ if (new_track < 0)
+ new_track = 0;
+ else if (new_track >= rl02_track_count)
+ new_track = rl02_track_count;
+ }
+
+ DOLOG(debug, false, "RL02: seek from cylinder %d to %d (distance: %d, DAR: %06o)", track, new_track, cylinder_count, temp);
+ track = new_track;
+
+ do_int = true;
+ }
+ else if (command == 6 || command == 7) { // read data / read data without header check
+ uint16_t temp = registers[(RL02_DAR - RL02_BASE) / 2];
+ sector = temp & 63;
+ head = !!(temp & 64);
+ track = temp >> 7;
+
+ uint32_t temp_disk_offset = calcOffset();
uint32_t memory_address = get_bus_address();
uint32_t count = (65536l - registers[(RL02_MPR - RL02_BASE) / 2]) * 2;
- DOLOG(debug, false, "RL02 read %d bytes (dec) from %d (dec) to %06o (oct)", count, disk_offset, memory_address);
+ DOLOG(debug, false, "RL02 read %d bytes (dec) from %d (dec) to %06o (oct) [cylinder: %d, head: %d, sector: %d]", count, temp_disk_offset, memory_address, track, head, sector);
while(count > 0) {
uint32_t cur = std::min(uint32_t(sizeof xfer_buffer), count);
@@ -160,15 +184,31 @@ void rl02::writeWord(const uint16_t addr, uint16_t v)
temp_disk_offset += cur;
count -= cur;
+
+ sector++;
+ if (sector >= rl02_sectors_per_track) {
+ sector = 0;
+
+ head++;
+ if (head >= 2) {
+ head = 0;
+
+ track++;
+ }
+ }
}
+ do_int = true;
+ }
+
+ if (do_int) {
if (registers[(RL02_CSR - RL02_BASE) / 2] & 64) { // interrupt enable?
DOLOG(debug, false, "RL02 triggering interrupt");
b->getCpu()->queue_interrupt(4, 0160);
}
-
- *disk_read_acitivity = false;
}
+
+ *disk_read_acitivity = false;
}
}
diff --git a/rl02.h b/rl02.h
index 06dc553..5bcd9bd 100644
--- a/rl02.h
+++ b/rl02.h
@@ -1,4 +1,4 @@
-// (C) 2018-2023 by Folkert van Heusden
+// (C) 2018-2024 by Folkert van Heusden
// Released under MIT license
#pragma once
@@ -19,6 +19,10 @@
#define RL02_BASE RL02_CSR
#define RL02_END (RL02_MPR + 2)
+constexpr const int rl02_sectors_per_track = 40;
+constexpr const int rl02_track_count = 512;
+constexpr const int rl02_bytes_per_sector = 256;
+
class bus;
class rl02
@@ -26,7 +30,10 @@ class rl02
private:
bus *const b;
uint16_t registers[4];
- uint8_t xfer_buffer[512];
+ uint8_t xfer_buffer[rl02_bytes_per_sector];
+ int16_t track { 0 };
+ uint8_t head { 0 };
+ uint8_t sector { 0 };
std::vector<disk_backend *> fhs;
std::atomic_bool *const disk_read_acitivity { nullptr };
@@ -34,7 +41,7 @@ private:
uint32_t get_bus_address() const;
void update_bus_address(const uint32_t a);
- uint32_t calcOffset(uint16_t) const;
+ uint32_t calcOffset() const;
public:
rl02(const std::vector<disk_backend *> & files, bus *const b, std::atomic_bool *const disk_read_acitivity, std::atomic_bool *const disk_write_acitivity);