prog8/examples/diskdir.p8

%import textio
%import syslib
%option no_sysinit
%zeropage basicsafe

; This example shows the directory contents of disk drive 8.
; Note: this program is compatible with C64 and CX16.

main {
    sub start() {
        txt.print("directory of disk drive #8:\n\n")
        diskdir(8)
    }

    sub diskdir(ubyte drivenumber) {
        c64.SETNAM(1, "$")
        c64.SETLFS(1, drivenumber, 0)
        void c64.OPEN()          ; open 1,8,0,"$"
        if_cs
            goto io_error
        void c64.CHKIN(1)        ; use #1 as input channel
        if_cs
            goto io_error

        repeat 4 {
            void c64.CHRIN()     ; skip the 4 prologue bytes
        }

        ; while not key pressed / EOF encountered, read data.
        ubyte status = c64.READST()
        while not status {
            txt.print_uw(mkword(c64.CHRIN(), c64.CHRIN()))
            txt.chrout(' ')
            ubyte @zp char
            do {
                char = c64.CHRIN()
                txt.chrout(char)
            } until char==0
            txt.chrout('\n')
            void c64.CHRIN()     ; skip 2 bytes
            void c64.CHRIN()
            status = c64.READST()
            void c64.STOP()
            if_nz
                break
        }

io_error:
        status = c64.READST()
        c64.CLRCHN()        ; restore default i/o devices
        c64.CLOSE(1)

        if status and status != 64 {            ; 64=end of file
            txt.print("\ni/o error, status: ")
            txt.print_ub(status)
            txt.chrout('\n')
        }
    }
}