Commodore Plus 4 - Page 102

90
The BASIC Language
Parameters: string variable, corner coordinates, opposite corner coordinates
1. The string variable is the name assigned to the graphic screen area saved
with the SSH APE command. Retrieve the area with GSH APE by using the same
string-variable name used in the SSHAPE command.
2. Give the coordinates for one corner of the shape you want to save.
3. Give the coordinates for the opposite (diagonal) corner.
Example: 10 GRAPHIC 1,1
SO FOR X = 0 TO 90STEP 10
30 CIRCLE, 160,100, 60,50,,,X,120
40 NEXT
45 REM SAVE AN AREA PROM THE DRAWING
50 SSHAPE A$, 90,60, 200,72
55 REM DISPLAY THE SAVED AREA IN REVERSE AT THE TOP OF
THE SCREEN
60 GSHAPEAl, 0,5,1
STatus
Abbr. none
Reserved variable name that contains a value representing the status of the
most recent input/output operation. You can read the status of most peripheral
devices. PRINT ST to display the status of the last operation using a peripheral; 0
usually means the operation was successful.
The following chart shows the status codes for I/O operations. See Chapter 6,
which contains detailed information about input/output operations.
Bit Value Tape I/O Serial I/O
RS232I/O
0
1
2
3
4
5
6
7
1
2
4
8
16
32
64
128
Short block
Long block
Read error
Checksum error
End of file
End of tape
Timeout write
Timeout read
—
—
—
—
End or identify
Device not present
Parity error
Framing error
Receiver buffer overrun
Receiver buffer empty
Clear to send missing
—
Data set ready missing
Break detected
For the 1541 disk drive, the end or identify bit set usually means the end of file
has been reached. Also, for a VERIFY, bit 4 set means a verify error was found.