{{htmlmetatags>metatag-robots=()
metatag-title=(FLOW CONTROL USING GOSUB..RETURN (1) | ugBASIC User Manual)
metatag-keywords=(ugBASIC,Commodore 64,Commodore PLUS/4,ZX Spectrum)
metatag-description=(An isomorphic language for retrocomputers)
metatag-media-og:image=(:ugbasic:logo-ugbasic-fb.png)
metatag-og:title=(FLOW CONTROL USING GOSUB..RETURN (1) | ugBASIC User Manual) 
metatag-og:description=(An isomorphic language for retrocomputers)
}}

====== ugBASIC User Manual ======

===== FLOW CONTROL USING GOSUB..RETURN (1) =====

==== PURPOSE ====
 This example will show the use of ''GOSUB...RETURN'' keywords. The main code will alternate the border colors, first yellow and after black. Each color will last for one second on the screen. The color change routine is a separate routine, called with ''GOSUB''. The border color is changed using the ''COLOR BORDER'' instruction, using the predefined constants ''YELLOW'' and ''BLACK''. To wait for a specific amount of time the ''WAIT'' command will be used, with the ''MS'' (milliseconds) unit of time.  

==== SOURCE CODE ====
   
       CLS
   
   start:
       GOSUB yellowBorder
       WAIT 1000 MS
       GOSUB blackBorder
       WAIT 1000 MS
       GOTO start
   
   yellowBorder:
       COLOR BORDER YELLOW
       HOME: PRINT "YELLOW"
       RETURN
   
   blackBorder:
       COLOR BORDER BLACK
       HOME: PRINT "BLACK "
       RETURN


==== SOURCE FILE ====
  * ''[[https://github.com/spotlessmind1975/ugbasic/tree/main/examples/control_returning_01.bas|control_returning_01.bas]]''
==== HOW TO COMPILE AND RUN ====
The instructions here refer to compiling the example from the command line. For Microsoft Windows users we suggest using **[[https://spotlessmind1975.itch.io/ugbasic-ide|UGBASIC-IDE]]**, which allows you to compile the example with just one click.=== ATARI 400/800 family ===
In order to compile and run the example, you need to have the Altirra emulator, and in particular that the ''altirra'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.atari control_returning_01.bas -o example.xex
   altirra example.xex
   
   # Windows 
   ugbc.atari.exe control_returning_01.bas -o example.xex
   altirra example.xex
=== ATARI 600XL/800XL/1200XL/XG(SE) family ===
In order to compile and run the example, you need to have the Altirra emulator, and in particular that the ''altirra'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.atarixl control_returning_01.bas -o example.xex
   altirra example.xex
   
   # Windows 
   ugbc.atarixl.exe control_returning_01.bas -o example.xex
   altirra example.xex
=== Commodore 64 ===
In order to compile and run the example, you need to have the VICE emulator, and in particular that the ''x64sc'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.c64 control_returning_01.bas -o example.prg
   x64sc example.prg
   
   # Windows 
   ugbc.c64.exe control_returning_01.bas -o example.prg
   x64sc example.prg
=== Commodore 64+REU ===
In order to compile and run the example, you need to have the VICE emulator, and in particular that the ''x64sc'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.c64reu control_returning_01.bas -o example.prg
   x64sc -reu example.prg
   
   # Windows 
   ugbc.c64reu.exe control_returning_01.bas -o example.prg
   x64sc -reu example.prg
=== Commodore PLUS/4 ===
== Using YAPE ==
In order to run the example, you need to have the YAPE emulator. In particular that the ''yape'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.plus4 control_returning_01.bas -o example.prg
   yape example.prg
   
   # Windows 
   ugbc.plus4.exe control_returning_01.bas -o example.prg
   yape example.prg
== Using VICE ==
In order to run the example, you need to have the VICE emulator. In particular that the ''xplus4'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.plus4 control_returning_01.bas -o example.prg
   xplus4 example.prg
   
   # Windows 
   ugbc.plus4.exe control_returning_01.bas -o example.prg
   xplus4 example.prg
=== Dragon 32 ===
In order to compile and run the example, you need to have the XROAR emulator, and in particular that the ''xroar'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.d32 control_returning_01.bas -o example.bin
   xroar -rompath (your rom path) example.bin
   
   # Windows 
   ugbc.d32.exe control_returning_01.bas -o example.bin
   xroar.exe -rompath (your rom path) example.bin
=== Dragon 64 ===
In order to compile and run the example, you need to have the XROAR emulator, and in particular that the ''xroar'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.d64 control_returning_01.bas -o example.bin
   xroar -rompath (your rom path) example.bin
   
   # Windows 
   ugbc.d64.exe control_returning_01.bas -o example.bin
   xroar.exe -rompath (your rom path) example.bin
=== PC128 Olivetti Prodest ===
In order to compile and run the example, you need to have the DCMOTO emulator, and in particular that the ''dcmoto'' executable is accessible.

Then, type this command on the command line and on the emulator:

   # Linux 
   ugbc.pc128op control_returning_01.bas -o example.k7
   dcmoto
   (choose BASIC 128)
   CLEAR,&H2FFF: LOADM"CASS:",R: EXEC
   
   # Windows 
   ugbc.pc128op.exe control_returning_01.bas -o example.k7
   dcmoto
   (choose example.k7)
   (choose BASIC 128)
   CLEAR,&H2FFF: LOADM"CASS:",R: EXEC
=== Thomson MO5 ===
In order to compile and run the example, you need to have the DCMOTO emulator, and in particular that the ''dcmoto'' executable is accessible.

Then, type this command on the command line and on the emulator:

   # Linux 
   ugbc.pc128op control_returning_01.bas -o example.k7
   dcmoto
   (choose BASIC 128)
   CLEAR,&H2FFF: LOADM"CASS:",R: EXEC
   
   # Windows 
   ugbc.pc128op.exe control_returning_01.bas -o example.k7
   dcmoto
   (choose example.k7)
   (choose BASIC 128)
   CLEAR,&H2FFF: LOADM"CASS:",R: EXEC
=== Commodore VIC-20 ===
In order to compile and run the example, you need to have the VICE emulator, and in particular that the ''xvic'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.vic20 control_returning_01.bas -o example.prg
   xvic --memory 24k example.prg
   
   # Windows 
   ugbc.vic20.exe control_returning_01.bas -o example.prg
   xvic --memory 24k example.prg
=== ZX Spectrum ===
In order to compile and run the example, you need to have the Speccy emulator, and in particular that the ''speccy'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.zx control_returning_01.bas -o example.tap
   Speccy example.tap
   
   # Windows 
   ugbc.zx.exe control_returning_01.bas -o example.tap
   Speccy example.tap
=== MSX ===
In order to compile and run the example, you need to have the openMsx or the BlueMSX emulator, and in particular that its executable is accessible.

Then, type this command on the command line:

== openMSX ==
   # Linux 
   ugbc.msx1 control_returning_01.bas -o example.rom
   openmsx -cart example.rom
   
   # Windows 
   ugbc.msx1.exe control_returning_01.bas -o example.rom
   openmsx -cart example.rom
== blueMSX ==
   # Linux 
   ugbc.msx1 control_returning_01.bas -o example.rom
   bluemsx example.rom
   
   # Windows 
   ugbc.msx1.exe control_returning_01.bas -o example.rom
   bluemsx example.rom
=== ColecoVision ===
In order to compile and run the example, you need to have the openMsx or the BlueMSX emulator, and in particular that its executable is accessible.

Then, type this command on the command line:

== openMSX ==
   # Linux 
   ugbc.coleco control_returning_01.bas -o example.rom
   openmsx -machine \"COL - ColecoVision\" -cart example.rom
   
   # Windows 
   ugbc.coleco.exe control_returning_01.bas -o example.rom
   bluemsx -machine \"COL - ColecoVision\" example.rom
== blueMSX ==
   # Linux 
   ugbc.coleco control_returning_01.bas -o example.rom
   bluemsx /machine \"COL - ColecoVision\" /rom1 example.rom
   
   # Windows 
   ugbc.coleco.exe control_returning_01.bas -o example.rom
   bluemsx  /machine \"COL - ColecoVision\" /rom1 example.rom
=== SEGA SC-3000 ===
In order to compile and run the example, you need to have the BlueMSX emulator, and in particular that its executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.sc3000 control_returning_01.bas -o example.rom
   bluemsx /machine \"SEGA - SC-3000\" /rom1 example.rom
   
   # Windows 
   ugbc.sc3000.exe control_returning_01.bas -o example.rom
   bluemsx  /machine \"SEGA - SC-3000\" /rom1 example.rom
=== SEGA SG-1000 ===
In order to compile and run the example, you need to have the BlueMSX emulator, and in particular that its executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.sg1000 control_returning_01.bas -o example.rom
   bluemsx /machine \"SEGA - SG-1000\" /rom1 example.rom
   
   # Windows 
   ugbc.sg1000.exe control_returning_01.bas -o example.rom
   bluemsx  /machine \"SEGA - SG-1000\" /rom1 example.rom
==== ANY PROBLEM? ====
If you have found a problem trying to run this example, if you think there is a bug or, more simply, you would like it to be improved, [[https://github.com/spotlessmind1975/ugbasic/issues/new?title=IMPROVE FLOW CONTROL USING GOSUB..RETURN (1)|open an issue]] for this example on GitHub. Thank you!===== POWERED BY =====

[[:ugbasic:user:examples|{{ :ugbasic:user:logo-ugbasic.png?nolink&600 |}}]]