Nascom News­let­ter

The command eliminates the spurious input of random characters which is often associated with the switch on and switch off of attatched tape recorders. Both the NAS-SYS and the SYS-EX read and verify commands (and also NAS-SYS 1 Load command) are unaffected in their operation by the action of the ‘k’ command. If required, the normal NAS-SYS tables may be restored by using the NAS-SYS ‘N’ command.

The command adds 4 to the ‘normal’ input table value and then stores this value using the NAS-SYS NIM function. This has the desired effect both in NAS-SYS 1 and NAS-SYS 3.

Writes a tape label with a specified name. Once written a tape label will be recognised and displayed by the SYS-EX commands ‘q’, ‘r’, ‘s’ and ‘v’.

After entry of the ‘l’ command, the prompt ‘lName:’ appears on the next screen line and the required label name is entered on that line. The tape drive LED is switched on and after about two seconds (4MHz), the tape label is sent to the serial output port for writing to tape. Finally, the tape drive LED is switched off.

The format of the tape label is as follows;

4 x D3H
0 to 42 characters of label name
1 space (00H if name length is 42)
00H.

File and label names are normally entered on the same line as the prompt ‘.Name:’ which immediately follows the entered command line. However, it is quite possible to enter a name from a different line after first moving the cursor to the line required. The name must begin in column 7 and must be immediately preceded by the : character (7CH = Control/​Shift/,). Any characters (including spaces) may be included in file and label names. All space characters which appear to the right of the final non-space character are ignored.

If the CLOAD command in the 8K Basic causes a tape label to be read, Basic will interpret the label as a program file with the name D3H (a block graphics character). This is unlikely to cause any problems.

Returns exclusively to NAS-SYS using a NAS-SYS MRET instruction.

This command will seldom be required as all of the NAS-SYS keyboard commands are available in the normal way from within SYS-EX.