"Aee

10

The screen seroils up one line, and the prompt and cursor return to
the bottom line, The move is complete.

Using the M command, check that addresses 6200 to 620F have
been loaded with the same values as those still remaining in
addresses 6000 to 600F.

This routine will allow you to move up or down memory, from any

original! starting address to any new starting address, even if the new
area overlaps the original area, The origina! area (unless over-written
by the move) is not changed.

Try moving the area from 6000 to 60OF to a new start address of
$008 and then move it back again.

A word of warning: Most MONITOR commands that allow you to
alter the values in memory locations, wil! operate on the area of
RAM containing the MONITOR routines. Always check carefully
that you are not about to corrupt the MONITOR, which occupies
the area from EEAC to FEF9, (48K); or GEAC to TEF9 (16K).

F — Fill an area with a given value ; J

The Fill routine allows you to enter the same byte value into a given
area of RAM, and takes the form: 'F aaaa bbbb xx', when aaaa and
bbbb are the start and end addresses respectively of the specified
area, and xx is the value to be entered.

Type X' to restore the prompt and cursor.
Type F to enter the F command.

Type 6020 the start address, ;

Type 6100 the end address, ;

Type AA the value to be entered. (Hex).
Type ENTER. ' to effect the Fill.

The screen serolls, and the prompt and cursor appear on the bottom
line of the screen, The fill is complete.

Now use the M command, with ENTER kept pressed, to verify that
each byte from 6020 to 6100 inclusive has a value of AA.

|
H
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s.

a | | De. | 11

Y — Return

Printed on the 'Y' key is the keyword RETURN, and by pressing
this key, followed by ENTER, when the prompt and cursor alone
are visible on the bottom line of the screen, a return to Basic is
effected so that you can use any of the Basic commands. As the
MONITOR does not have its own Save and Load commands, you
will need the Return command to use the Basic Save and Load.

16, having returned to Basic, you wish to access the MONITOR again
the following addresses should be used with the USR function,
depending upon which version of the MONITOR you are using:

16k version:
43K version:

type RANDOMIZE USR 30479
typo RANDOMIZE USR 63247

followed by ENTER,

Using the MONITOR 'Return' command, will reset the stack, but
wil not affect the Basic listing or the variables.

To demonstrate the remaining commands of the MONITOR, use the
"'M" command to enter the following short program, starting at

6000 01 00 00 LO  BC,0000 ; Clear BC
6003 11 00 00 LD ' DE,O00O ; Clear DE
6006 21 00 00 LD  HL,0000 ; Clear HL.
6009 03 INC BC $ BoBo:
GOO0A 13 INC DE DE OREL 01
6008 23 INC HE: 7 HL<EHL101
600€ C9 ič nET ; Return.
Start 6000

End 600C

Having entered Hex codes, go back to 6000 and check that the
codes are correct. (Type M 6000 and check the contents of each
location).

Ht is recommended that you would narmally Save a machine code
program before running it in case it crashes, which it iz certainly
likely to do unless you are an experienced machine code
programmer, In this case, there is no real point in Saving the
program, but if you wish to do so, refer to the section on ''The
Monitor in practice".