1 files changed, 63 insertions, 0 deletions
diff --git a/sys/ki/kzrdmt.x b/sys/ki/kzrdmt.x
new file mode 100644
index 00000000..7fdaf517
--- /dev/null
+++ b/sys/ki/kzrdmt.x
@@ -0,0 +1,63 @@
+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include	<mach.h>
+include	<config.h>
+include	<fio.h>
+include	"ki.h"
+
+# KZRDMT -- Asynchronous read from a magtape file.
+
+procedure kzrdmt (chan, obuf, max_bytes, offset)
+
+int	chan			#I magtape channel
+char	obuf[ARB]		#O buffer to receive data
+int	max_bytes		#I max bytes to read
+long	offset			#I file offset
+
+pointer	bd
+int	server, status
+int	ki_send(), ki_receive()
+include	"kichan.com"
+include	"kii.com"
+
+begin
+	server = k_node[chan]
+
+	if (server == NULL) {
+	    call zzrdmt (k_oschan[chan], obuf, max_bytes, offset)
+	    return
+	}
+
+	# Ignore zero reads and requests on a node closed by an error.
+	if (max_bytes <= 0) {
+	    k_status[chan] = 0
+	    return
+	}
+
+	# Send the request to initiate the read.
+	p_arg[1] = k_oschan[chan]
+	p_arg[2] = max_bytes
+	p_arg[3] = offset
+
+	if (ki_send (server, KI_ZFIOMT, MT_RD) == ERR) {
+	    status = ERR
+	} else {
+	    bd = k_bufp[chan]
+
+	    # Wait for the ZAWT packet.
+	    if (ki_receive (server, KI_ZFIOMT, MT_WT) == ERR)
+		status = ERR
+	    else {
+		status = p_arg[1]
+		call amovi (p_arg[2], Memi[bd], LEN_MTDEVPOS)
+	    }
+
+	    # Read the data block (if any) directly into caller's buffer.
+	    if (status > 0) {
+		call ks_aread (server, obuf, status)
+		call ks_await (server, status)
+	    }
+	}
+
+	k_status[chan] = status
+end