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Delete a single byte at a specified memory location and move the contents of higher memory locations down to fill the gap.

The section of memory delimited by: (i) address for deletion plus one, (ii) top limit for move minus one, is moved to the memory locations delimited by (i) address for deletion, (ii) top Limit for move minus two. The ‘top limit for move’ parameter is the first memory address from and above which memory is neither read from nor written to by this command. The top limit for move must by greater than the address for deletion by at least two bytes.

After deletion of the specified byte, the command responds by displaying on the following screen line the hexadecimal value of the deleted byte.

AAAA – memory address at which the byte is to be deleted
BBBB – top limit for move. Memory addresses from this address upwards are not accessed.

The command uses the Z80 block transfer instruction LDIR to shift the contents of memory downwards.

Find a specified character string, or a sequence of bytes specified by hexadecimal values, and display the memory address(es) at which it occurs.

The memory address at which the search is to start is taken from the first argument (ARG1).

After entry of the “f’ command, the cursor is positioned at the start of the next line and the find mask may then be entered in one of the following two formats.

1. Character string

Theirst position in the mask line must contain the double-quote character ("). The required character string must start in the second position in the line and may contain any characters (including spaces) except the double-quote character. The string is terminated by a further double-quote character or, if this is not present, the end of the line.

2. Sequence of bytes pacified by hexadecimal values.

The mask is entered as a sequence of single byte hexadecimal numbers (0 to FF), each one separated from the next by at least one apace. The first value may start in the first position on the line or may be preceded by as many spaces as are required. The entire find mask must be contained within a single line.

After entry of the mask, memory is searched from the specified start address up to the top end of memory (FFFFH). The response is always displayed on the screen line following the entered mask. If no match is found, the response is XXXX.