Files
RTmFM/firmware/Test/Test.ino
2025-09-05 21:59:54 +01:00

906 lines
21 KiB
C++

#include <CLI.h>
#include <SdFat.h>
#include "datastream.h"
#define SDIO_CLK 16
#define SDIO_CMD 17
#define SDIO_DAT0 18
#define SDIO_DAT1 19
#define SDIO_DAT2 20
#define SDIO_DAT3 21
#define SECTOR_128 0
#define SECTOR_256 1
#define SECTOR_512 2
#define SECTOR_1024 3
#define INDEX 13
#define DOUT 12
#define STEP 7
#define DIR 8
#define SEEK_DONE 9
#define TRACK0 10
#define HSEL0 4
#define HSEL1 5
#define HSEL2 6
#define HSEL3 7
static PIOProgram datastreamPgm(&datastream_program);
PIO pio;
int sm;
int offset;
int dma;
uint32_t loadtime;
uint32_t current_head = 0;
uint32_t current_cyl = 0;
uint32_t current_sector = 0;
#define POLY16 0x1021
#define POLY32 0xa00805
#define NUM_SECTORS 17
#define TRACK_SIZE (512 * NUM_SECTORS)
uint8_t track_data[512 * 17 * 16];
#define OPT_HEADER_CRC16 0x00000001
#define OPT_HEADER_CRC32 0x00000002
#define OPT_HEADER_CRC_MASK 0xFFFFFFFC
#define OPT_DATA_CRC16 0x00000004
#define OPT_DATA_CRC32 0x00000008
#define OPT_DATA_CRC_MASK 0xFFFFFFF3
SdFs sd;
FsFile mounted_file;
struct disk_format {
uint16_t cyls;
uint8_t heads;
uint8_t sectors;
uint8_t sector_size;
uint32_t index_width;
uint32_t track_pregap;
uint32_t track_postgap;
uint32_t header_postgap;
uint32_t data_postgap;
float data_rate;
uint32_t flags;
uint32_t header_poly;
uint32_t data_poly;
// Calculated data - not to be filled.
uint32_t tlen;
uint32_t slen;
uint32_t idx_ts;
uint32_t idx_period;
float clock_div;
};
struct disk_format RD54 = {
1225, // Cyl
15, // Heads
17, // Sectors,
SECTOR_512, // Bytes per sector
10, // Index width - how long the index pulse is low
290, // Track pregap - Time between index pulse and first sync byte
1100, // Track postgap - Time between last sync byte and index pulse
41, // Header postgap - Time between header sync byte and data sync byte
911, // Data postgap - Time between data sync byte and header sync byte of next sector
5000000, // Data Rate
OPT_HEADER_CRC16 | OPT_DATA_CRC32,
0x1021, // Header CRC polynomial
0xa00805, // Data CRC polynomial
};
struct sector {
uint16_t header[10];
uint16_t data[520];
};
struct disk_format *format;
void bindump(uint16_t v) {
for (int i = 0; i < 16; i++) {
v <<= 1;
}
}
uint16_t crc16(uint8_t val, uint16_t crc, uint16_t poly)
{
uint16_t xval = val;
int j;
crc = crc ^ (xval << 8);
for (j = 1; j <= 8; j++) {
if (crc & 0x8000) {
crc = (crc << 1) ^ poly;
} else {
crc = crc << 1;
}
}
return crc;
}
uint32_t crc32(uint8_t val, uint32_t crc, uint32_t poly)
{
int j;
crc = crc ^ (val << 24);
for (j = 1; j <= 8; j++) {
if (crc & 0x80000000) {
crc = (crc << 1) ^ poly;
} else {
crc = crc << 1;
}
}
return crc;
}
uint8_t last_bit = 0;
uint16_t mfm_encode_bit(uint8_t b) {
if (b == 0x80) {
last_bit = 1;
return 0b01;
}
if (last_bit == 0) {
return 0b10;
} else {
last_bit = 0;
return 0b00;
}
}
uint16_t mfm_encode(uint8_t b, bool reset = false) {
if (reset) {
last_bit = 0;
}
uint16_t out = 0;
for (int i = 0; i < 8; i++) {
out <<= 2;
out |= mfm_encode_bit(b & 0x80);
b <<= 1;
}
return out;
}
enum {
PH_INDEX_START,
PH_INDEX_END,
PH_TRACK_PREGAP,
PH_SEND_HEADER,
PH_HEADER_POSTGAP,
PH_SEND_DATA,
PH_DATA_POSTGAP,
PH_TRACK_POSTGAP
};
enum {
LOAD_IDLE,
LOAD_HEADER,
LOAD_DATA,
LOAD_DATA_RUN,
LOAD_HEADER_CS,
LOAD_DATA_CS,
LOAD_HEADER_MFM,
LOAD_DATA_MFM,
LOAD_SYNC
};
void second_cpu_thread() {
dma = dma_claim_unused_channel(true);
dma_channel_config config = dma_channel_get_default_config(dma);
channel_config_set_read_increment(&config, true);
channel_config_set_write_increment(&config, false);
channel_config_set_dreq(&config, pio_get_dreq(pio, sm, true));
channel_config_set_transfer_data_size(&config, DMA_SIZE_16);
uint32_t ts = micros();
int phase = 0;
int load_sm = LOAD_IDLE;
int load_iter = 0;
uint16_t load_hcs = 0;
uint32_t load_dcs = 0;
int next_sector = 1;
current_sector = 0;
struct sector sectorA;
struct sector sectorB;
struct sector *load = &sectorA;
struct sector *send = &sectorB;
struct sector *swap;
// load_sector(load, current_cyl, current_head, current_sector, &track_data[0]);
pinMode(HSEL0, INPUT);
pinMode(HSEL1, INPUT);
pinMode(HSEL2, INPUT);
pinMode(HSEL3, INPUT);
while (1) {
uint16_t hp = format->header_poly;
uint32_t dp = format->data_poly;
current_head = digitalRead(HSEL0) | (digitalRead(HSEL1) << 1) | (digitalRead(HSEL2) << 2) | (digitalRead(HSEL3) << 3);
switch (phase) {
case PH_INDEX_START: // Start index pulse
ts = micros();
format->idx_period = micros() - format->idx_ts;
format->idx_ts = micros();
digitalWrite(INDEX, LOW);
phase++;
break;
case PH_INDEX_END: // Index pulse timing
if ((micros() - ts) >= format->index_width) {
ts = micros();
digitalWrite(INDEX, HIGH);
phase++;
}
break;
case PH_TRACK_PREGAP: // Track pre-gap
if ((micros() - ts) >= format->track_pregap) {
ts = micros();
phase = PH_SEND_HEADER;
}
break;
case PH_SEND_HEADER:
ts = micros();
swap = load;
load = send;
send = swap;
dma_channel_configure(dma, &config,
&pio->txf[sm],
send->header,
10,
true
);
next_sector = (current_sector + 1) % format->sectors;
//load_sector(load, current_cyl, current_head, next_sector, &track_data[512 * next_sector]);
load_sm = LOAD_HEADER;
phase = PH_HEADER_POSTGAP;
break;
case PH_HEADER_POSTGAP:
if ((micros() - ts) >= format->header_postgap) {
ts = micros();
phase = PH_SEND_DATA;
}
break;
case PH_SEND_DATA:
ts = micros();
dma_channel_configure(dma, &config,
&pio->txf[sm],
send->data,
520,
true
);
//next_sector = (current_sector + 1) % format->sectors;
//load_sector(load, current_cyl, current_head, next_sector, &track_data[512 * next_sector]);
//load_sm = LOAD_HEADER;
if (current_sector < format->sectors - 1) {
phase = PH_DATA_POSTGAP;
} else {
phase = PH_TRACK_POSTGAP;
}
break;
case PH_DATA_POSTGAP:
if ((micros() - ts) > format->data_postgap) {
ts = micros();
current_sector++;
phase = PH_SEND_HEADER;
}
break;
case PH_TRACK_POSTGAP:
if ((micros() - ts) > format->track_postgap) {
ts = micros();
current_sector = 0;
phase = PH_INDEX_START;
}
break;
}
// Sector loading state machine
switch (load_sm) {
case LOAD_IDLE: // Waiting for instruction
break;
case LOAD_HEADER:
load->header[0] = 0;
load->header[1] = 0xA1;
load->header[2] = 0xFE;
load->header[3] = (current_cyl & 0xFF);
load->header[4] = ((current_cyl & 0xF00) >> 4) | (current_head & 0x0F);
load->header[5] = next_sector;
load->header[6] = format->sector_size;
load->header[7] = 0x00;
load->header[8] = 0x00;
load->header[9] = 0;
load_sm = LOAD_DATA;
break;
case LOAD_DATA:
load->data[0] = 0;
load->data[1] = 0xA1;
load->data[2] = 0xFB;
load_iter = 0;
load_sm = LOAD_DATA_RUN;
break;
case LOAD_DATA_RUN:
load->data[load_iter + 3] = track_data[512 * next_sector + load_iter];
load_iter++;
if (load_iter == 512) {
load_sm = LOAD_HEADER_CS;
load_iter = 1;
load_hcs = 0xFFFF;
}
break;
case LOAD_HEADER_CS:
load_hcs = crc16(load->header[load_iter], load_hcs, hp);
load_iter++;
if (load_iter == 7) {
load->header[7] = (load_hcs >> 8) & 0xFF;
load->header[8] = load_hcs & 0xFF;
load_iter = 1;
load_dcs = 0xFFFFFFFF;
load_sm = LOAD_DATA_CS;
}
break;
case LOAD_DATA_CS:
load_dcs = load_iter < 515 ? crc32(load->data[load_iter], load_dcs, dp) : load_dcs;
load_iter++;
load_dcs = load_iter < 515 ? crc32(load->data[load_iter], load_dcs, dp) : load_dcs;
load_iter++;
load_dcs = load_iter < 515 ? crc32(load->data[load_iter], load_dcs, dp) : load_dcs;
load_iter++;
load_dcs = load_iter < 515 ? crc32(load->data[load_iter], load_dcs, dp) : load_dcs;
load_iter++;
load_dcs = load_iter < 515 ? crc32(load->data[load_iter], load_dcs, dp) : load_dcs;
load_iter++;
load_dcs = load_iter < 515 ? crc32(load->data[load_iter], load_dcs, dp) : load_dcs;
load_iter++;
load_dcs = load_iter < 515 ? crc32(load->data[load_iter], load_dcs, dp) : load_dcs;
load_iter++;
load_dcs = load_iter < 515 ? crc32(load->data[load_iter], load_dcs, dp) : load_dcs;
load_iter++;
load_dcs = load_iter < 515 ? crc32(load->data[load_iter], load_dcs, dp) : load_dcs;
load_iter++;
load_dcs = load_iter < 515 ? crc32(load->data[load_iter], load_dcs, dp) : load_dcs;
load_iter++;
if (load_iter >= 515) {
load->data[515] = (load_dcs >> 24) & 0xFF;
load->data[516] = (load_dcs >> 16) & 0xFF;
load->data[517] = (load_dcs >> 8) & 0xFF;
load->data[518] = load_dcs & 0xFF;
load->data[519] = 0;
load_iter = 0;
load_sm = LOAD_HEADER_MFM;
}
break;
case LOAD_HEADER_MFM:
load->header[0] = mfm_encode(load->header[0], true);
load->header[1] = mfm_encode(load->header[1], false) & 0b1111111111011111;
load->header[2] = mfm_encode(load->header[2], false);
load->header[3] = mfm_encode(load->header[3], false);
load->header[4] = mfm_encode(load->header[4], false);
load->header[5] = mfm_encode(load->header[5], false);
load->header[6] = mfm_encode(load->header[6], false);
load->header[7] = mfm_encode(load->header[7], false);
load->header[8] = mfm_encode(load->header[8], false);
load->header[9] = mfm_encode(load->header[9], false);
load_sm = LOAD_DATA_MFM;
break;
case LOAD_DATA_MFM:
load->data[load_iter] = mfm_encode(load->data[load_iter], load_iter == 0);
load_iter++;
if (load_iter == 1) {
load->data[load_iter] = mfm_encode(load->data[load_iter], load_iter == 0) & 0b1111111111011111;
} else {
load->data[load_iter] = mfm_encode(load->data[load_iter], load_iter == 0);
}
load_iter++;
load->data[load_iter] = mfm_encode(load->data[load_iter], load_iter == 0);
load_iter++;
load->data[load_iter] = mfm_encode(load->data[load_iter], load_iter == 0);
load_iter++;
load->data[load_iter] = mfm_encode(load->data[load_iter], load_iter == 0);
load_iter++;
load->data[load_iter] = mfm_encode(load->data[load_iter], load_iter == 0);
load_iter++;
load->data[load_iter] = mfm_encode(load->data[load_iter], load_iter == 0);
load_iter++;
load->data[load_iter] = mfm_encode(load->data[load_iter], load_iter == 0);
load_iter++;
load->data[load_iter] = mfm_encode(load->data[load_iter], load_iter == 0);
load_iter++;
load->data[load_iter] = mfm_encode(load->data[load_iter], load_iter == 0);
load_iter++;
if (load_iter >= 520) {
// digitalWrite(INDEX, LOW);
// digitalWrite(INDEX, HIGH);
load_sm = LOAD_IDLE;
}
break;
case LOAD_SYNC:
load->header[1] &= 0b1111111111011111;
load->data[1] &= 0b1111111111011111;
load_sm = LOAD_IDLE;
break;
}
}
}
void load_sector(struct sector *s, int cno, int hno, int secno, uint8_t *data) {
uint32_t ts = micros();
uint16_t hp = format->header_poly;
uint32_t dp = format->data_poly;
s->header[0] = 0;
s->header[1] = 0xA1;
s->header[2] = 0xFE;
s->header[3] = (cno & 0xFF);
s->header[4] = ((cno & 0xF00) >> 4) | (hno & 0x0F);
s->header[5] = secno;
s->header[6] = 0x02;
uint16_t crc = 0xFFFF;
for (int i = 1; i < 7; i++) {
crc = crc16(s->header[i], crc, hp);
}
s->header[7] = (crc >> 8) & 0xFF;
s->header[8] = crc & 0xFF;
s->header[9] = 0;
for (int i = 0; i < 10; i++) {
s->header[i] = mfm_encode(s->header[i], i == 0);
}
s->header[1] &= 0b1111111111011111;
s->data[0] = 0;
s->data[1] = 0xA1;
s->data[2] = 0xFB;
for (int i = 0; i < 512; i++) {
s->data[3 + i] = data[i];
}
uint32_t c32 = 0xFFFFFFFF;
for (int i = 1; i < 515; i++) {
c32 = crc32(s->data[i], c32, dp);
}
s->data[515] = (c32 >> 24) & 0xFF;
s->data[516] = (c32 >> 16) & 0xFF;
s->data[517] = (c32 >> 8) & 0xFF;
s->data[518] = c32 & 0xFF;
s->data[519] = 0;
for (int i = 0; i < 520; i++) {
s->data[i] = mfm_encode(s->data[i], i == 0);
}
s->data[1] &= 0b1111111111011111;
loadtime = micros() - ts;
}
void load_cyl(FsFile file, uint8_t *data, uint32_t cyl, uint32_t heads, uint32_t sectors, uint32_t sectorsize) {
uint32_t len = 0x80 << sectorsize;
len *= sectors;
len *= heads;
uint32_t offset = cyl * len;
file.seekSet(offset);
file.read(data, len);
}
CLI_COMMAND(cli_status) {
uint32_t sector_bytes = 8 + format->slen + 6 + format->header_postgap + format->data_postgap + 4;
uint32_t total_clocks = ((sector_bytes * format->sectors) + format->track_pregap + format->track_postgap + 1) * 8;
if ((argc == 2) && (strcmp(argv[1], "ini") == 0)) {
dev->print("cyls="); dev->println(format->cyls);
dev->print("heads="); dev->println(format->heads);
dev->print("sectors="); dev->println(format->sectors);
dev->print("sector_size="); dev->println(0x80 << format->sector_size);
dev->print("track_pregap="); dev->println(format->track_pregap);
dev->print("track_postgap="); dev->println(format->track_postgap);
dev->print("header_postgap="); dev->println(format->header_postgap);
dev->print("data_postgap="); dev->println(format->data_postgap);
dev->print("data_rate="); dev->println(format->data_rate);
dev->print("header_crc="); dev->println((format->flags & OPT_HEADER_CRC16) ? "16" : (format->flags & OPT_HEADER_CRC32) ? "32" : "ERROR");
dev->print("data_crc="); dev->println((format->flags & OPT_DATA_CRC16) ? "16" : (format->flags & OPT_DATA_CRC32) ? "32" : "ERROR");
dev->print("header_poly="); dev->println(format->header_poly, HEX);
dev->print("data_poly="); dev->println(format->data_poly, HEX);
return 0;
}
float rpm = (format->data_rate / total_clocks) * 60.0;
dev->print("Cylinders: ");
dev->println(format->cyls);
dev->print("Heads: ");
dev->println(format->heads);
dev->print("Sectors: ");
dev->println(format->sectors);
dev->print("Sector Size: ");
dev->print(0x80 << format->sector_size);
dev->println(" bytes");
dev->println();
dev->print("Header CRC Bits: ");
dev->println((format->flags & OPT_HEADER_CRC16) ? "16" : (format->flags & OPT_HEADER_CRC32) ? "32" : "ERROR");
dev->print("Data CRC Bits: ");
dev->println((format->flags & OPT_DATA_CRC16) ? "16" : (format->flags & OPT_DATA_CRC32) ? "32" : "ERROR");
dev->print("Header CRC Polynomial: ");
dev->println(format->header_poly, HEX);
dev->print("Data CRC Polynomial: ");
dev->println(format->data_poly, HEX);
dev->println();
dev->print("Track Pregap: ");
dev->print(format->track_pregap);
dev->println(" bytes");
dev->print("Track Postgap: ");
dev->print(format->track_postgap);
dev->println(" bytes");
dev->print("Header Postgap: ");
dev->print(format->header_postgap);
dev->println(" bytes");
dev->print("Data Postgap: ");
dev->print(format->data_postgap);
dev->println(" bytes");
dev->println();
dev->print("Total clocks per track: ");
dev->println(total_clocks);
dev->print("Calculated RPM: ");
dev->println(rpm);
dev->print("Actual RPM: ");
float p = format->idx_period / 1000000.0;
float f = 1.0 / p;
float r = f * 60;
dev->println(r);
dev->print("Requested Data Rate: ");
dev->print(format->data_rate);
dev->println("Hz");
dev->print("Actual Data Rate: ");
dev->print(F_CPU / format->clock_div / 20.0);
dev->println("Hz");
dev->print("Clock divider: ");
dev->println(format->clock_div);
dev->println();
dev->print("PIO: ");
dev->println(PIO_NUM(pio));
dev->print("State Machine: ");
dev->println(sm);
dev->print("Offset: ");
dev->println(offset);
dev->println();
dev->print("Load time: ");
dev->print(loadtime);
dev->println("uS");
dev->println();
dev->print("Current C/H/S: ");
dev->print(current_cyl);
dev->print("/");
dev->print(current_head);
dev->print("/");
dev->println(current_sector);
return 0;
}
CLI_COMMAND(cli_set) {
if (argc != 3) {
dev->println("Usage: set <item> <value>");
dev->println("Possible items:");
dev->println(" track_pregap");
dev->println(" track_posthap");
dev->println(" header_postgap");
dev->println(" data_postgap");
dev->println(" data_rate");
dev->println(" header_crc");
dev->println(" data_crc");
dev->println(" header_poly");
dev->println(" data_poly");
return 10;
}
if (strcmp(argv[1], "track_pregap") == 0) {
format->track_pregap = strtoul(argv[2], NULL, 10);
return 0;
}
if (strcmp(argv[1], "track_postgap") == 0) {
format->track_postgap = strtoul(argv[2], NULL, 10);
return 0;
}
if (strcmp(argv[1], "header_postgap") == 0) {
format->header_postgap = strtoul(argv[2], NULL, 10);
return 0;
}
if (strcmp(argv[1], "data_postgap") == 0) {
format->data_postgap = strtoul(argv[2], NULL, 10);
return 0;
}
if (strcmp(argv[1], "data_rate") == 0) {
float r = strtof(argv[2], NULL);
float cd = F_CPU / r / 20.0;
if (cd < 1) {
dev->println("Data rate too high for the CPU clock");
return 10;
}
format->data_rate = r;
format->clock_div = cd;
pio_sm_set_clkdiv(pio, sm, format->clock_div);
return 0;
}
if (strcmp(argv[1], "header_crc") == 0) {
int c = strtol(argv[2], NULL, 10);
if (c == 16) {
format->flags &= OPT_HEADER_CRC_MASK;
format->flags |= OPT_HEADER_CRC16;
return 0;
}
if (c == 32) {
format->flags &= OPT_HEADER_CRC_MASK;
format->flags |= OPT_HEADER_CRC32;
return 0;
}
dev->println("Error: header_crc must be 16 or 32");
return 10;
}
if (strcmp(argv[1], "data_crc") == 0) {
int c = strtol(argv[2], NULL, 10);
if (c == 16) {
format->flags &= OPT_DATA_CRC_MASK;
format->flags |= OPT_DATA_CRC16;
return 0;
}
if (c == 32) {
format->flags &= OPT_DATA_CRC_MASK;
format->flags |= OPT_DATA_CRC32;
return 0;
}
dev->println("Error: data_crc must be 16 or 32");
return 10;
}
if (strcmp(argv[1], "header_poly") == 0) {
format->header_poly = strtoul(argv[2], NULL, 16);
return 0;
}
if (strcmp(argv[1], "data_poly") == 0) {
format->data_poly = strtoul(argv[2], NULL, 16);
return 0;
}
dev->println("Possible items:");
dev->println(" track_pregap");
dev->println(" track_posthap");
dev->println(" header_postgap");
dev->println(" data_postgap");
return 10;
}
CLI_COMMAND(cli_ls) {
sd.ls(LS_A | LS_DATE | LS_SIZE);
return 0;
}
CLI_COMMAND(cli_create) {
if (argc != 2) {
dev->println("Usage: create <filename>");
dev->println("Create a new image file using the current disk format");
return 10;
}
if (sd.exists(argv[1])) {
dev->println("File already exists");
return 10;
}
uint32_t disk_size = 0x80 << format->sector_size;
disk_size *= format->sectors;
disk_size *= format->heads;
disk_size *= format->cyls;
dev->println("Creating new file, please wait...");
FsFile newfile;
newfile.open(argv[1], O_RDWR | O_CREAT);
newfile.preAllocate(disk_size);
newfile.close();
return 0;
}
CLI_COMMAND(cli_mount) {
if (argc != 2) {
dev->println("Usage: mount <filename>");
dev->println("Mount an image file as the virtual disk");
return 10;
}
if (!sd.exists(argv[1])) {
dev->println("File not found");
return 10;
}
mounted_file = sd.open(argv[1], O_RDWR);
current_cyl = 0;
current_head = 0;
load_cyl(mounted_file, track_data, current_cyl, format->heads, format->sectors, format->sector_size);
return 0;
}
void do_step() {
digitalWrite(SEEK_DONE, LOW);
int dir = digitalRead(DIR);
if (dir == 1 && current_cyl == 0) {
// No can do.
digitalWrite(SEEK_DONE, HIGH);
return;
}
if (dir == 1) {
current_cyl --;
} else {
current_cyl ++;
}
if (current_cyl >= format->cyls) {
current_cyl = 0;
}
load_cyl(mounted_file, track_data, current_cyl, format->heads, format->sectors, format->sector_size);
digitalWrite(TRACK0, current_cyl == 0);
digitalWrite(SEEK_DONE, HIGH);
}
void setup() {
if (!sd.begin(SdioConfig(SDIO_CLK, SDIO_CMD, SDIO_DAT0, 1.5))) {
sd.initErrorPrint();
}
datastreamPgm.prepare(&pio, &sm, &offset);
datastream_program_init(pio, sm, offset, DOUT);
pio_sm_set_enabled(pio, sm, true);
pio->txf[sm] = mfm_encode(0x00);
pinMode(13, OUTPUT);
digitalWrite(13, HIGH);
Serial.begin(115200);
format = &RD54;
format->slen = 0x80 << format->sector_size;
format->tlen = format->slen * format->sectors;
for (int i = 0; i < 512 * 17; i++) {
track_data[i] = rand();
}
format->clock_div = F_CPU / format->data_rate / 20.0;
pio_sm_set_clkdiv(pio, sm, format->clock_div);
multicore_launch_core1(second_cpu_thread);
Serial.begin(115200);
CLI.setDefaultPrompt("RTmFM> ");
CLI.addClient(Serial);
CLI.addCommand("status", cli_status);
CLI.addCommand("set", cli_set);
CLI.addCommand("ls", cli_ls);
CLI.addCommand("create", cli_create);
CLI.addCommand("mount", cli_mount);
pinMode(STEP, INPUT);
pinMode(DIR, INPUT);
pinMode(SEEK_DONE, OUTPUT);
digitalWrite(SEEK_DONE, HIGH);
pinMode(TRACK0, OUTPUT);
digitalWrite(TRACK0, current_cyl == 0);
attachInterrupt(STEP, do_step, RISING);
}
void loop() {
CLI.process();
}