/*
*   Z M O D E M . H     Manifest constants for ZMODEM
*    application to application file transfer protocol
*    05-23-87  Chuck Forsberg Omen Technology Inc
*/
#define ZPAD       '*'  // ZPAD starts every header
#define ZDLE       24  // The general purpose escape code
#define ZBIN       'A'  // Starts a binary CRC-16 frame
#define ZHEX       'B'  // Starts a hex CRC-16 frame
#define ZBIN32     'C'  // Starts a binary CRC-32 frame
#define ZMAXSPLEN  1024 // Max subpacket length

// These constants define all the various frame types

#define ZRQINIT    0    // Request for receiver init frame
#define ZRINIT     1    // A receiver init frame
#define ZSINIT     2   // A sender init frame
#define ZACK       3   // General purpose Acknowledge frame
#define ZFILE      4    // File name and data
#define ZSKIP      5    // Skip the incoming file
#define ZNAK       6    // General purpose Not Acknowledge
#define ZABORT     7    // Abort session
#define ZFIN       8    // Session is complete
#define ZRPOS      9    // Request to start sending from a
// specific address
#define ZDATA      10   // Start of a data frame
#define ZEOF       11   // End of file
#define ZFERR      12   // Fatal Read or Write error D
#define ZCRC       13   // Request for CRC value of a file
#define ZCHALLENGE 14   // Challenge frame
#define ZCOMPL     15   // Request is complete
#define ZCAN       16   // Remote end canceled
#define ZFREECNT   17   // Request for free bytes 
// available on the target filesystem
#define ZCOMMAND   18   // Command from sending program
#define ZSTDERR    19   // Output to stderr data follows

// Escape sequences in binary data

#define ZCRCE      'h'  // CRC next, frame ends, header 
// follows
#define ZCRCG      'i'  // CRC next, frame continues nonstop
#define ZCRCQ      'j'  // CRC next, frame conts., expect ZACK
#define ZCRCW      'k'  // CRC next, ZACK expected, 
// end of frame
#define ZRUB0      'l'  // Translate to rubout, 0x7f
#define ZRUB1      'm'  // Translate to rubout, 0xff

// ReadDataFrame() return values

#define GOTFLAG    0x100
#define GOTCRCE    (ZCRCE | GOTFLAG)  // ZDLE-ZCRCE received
#define GOTCRCG    (ZCRCG | GOTFLAG)  // ZDLE-ZCRCG received
#define GOTCRCQ    (ZCRCQ | GOTFLAG)  // ZDLE-ZCRCQ received
#define GOTCRCW    (ZCRCW | GOTFLAG) // ZDLE-ZCRCW received
#define GOTCAN     (CAN   | GOTFLAG)  // CAN*5 seen

// Byte positions within header array

#define ZF0        3        // Position 0 in the flags array
#define ZF1        2
#define ZF2        1
#define ZF3        0
#define ZP0        0       // Low order 8 bits of position
#define ZP1        1
#define ZP2        2
#define ZP3        3

// Bit Masks for ZRINIT flags byte ZF0

#define CANFDX     0x01 // Rx can send and receive true 
// full duplex
#define CANOVIO    0x02 // Rx can receive data during disk I/O
#define CANBRK     0x04 // Rx can send a break signal
#define CANRLE     0x08 // Receiver can decode RLE
#define CANLZW     0x10 // Receiver can uncompress
#define CANFC32    0x20 // Receiver can use 32 bit CRC
#define ESCCTL     0x40 // Receiver expects ctl chars 
// to be escaped
#define ESC8       0x80 // Receiver expects 8th bit 
// to be escaped

// Miscellaneous constants

const int OK = 0;
#define ZERROR          -1
#define TIMEOUT        -2
#define GARBAGE_COUNT  -3

#define BS    8
#define LF    10
#define CR    13
#define DLE   16
#define XON   17
#define XOFF  19
#define CAN   24
#define ESC   27