User Tools
en
itTable of Contents
ugBASIC User Manual
MATHEMATIC ROUTINES LIMITS OF NUMERIC TYPES
PURPOSE
This example attempts to show the behavior of the system when dealing with conversion between types, signed or unsigned. The rule that ugBASIC uses is the minimum error rule: in general, if the destination type has a sufficient number of bits, it is possible to represent the information without losses. If the destination type has fewer bits, the number is guaranteed to be represented correctly if the number of destination bits are sufficient. In case of signed types, if the source number is negative but the destination type is unsigned, the value will be set to the absolute value without sign.
SOURCE CODE
PROCEDURE example ON ALL BUT VIC20
CLS
' ******************************************************************
' ******** destination: signed byte ********************************
' ******************************************************************
DIM sb AS SIGNED BYTE
' source underflow -> destination underflow
'
' -42 = 11010110 -> 11010110 -> -42
sb = -42
PRINT "signed byte(-42) = "; sb; " (exp ";"-42";" )"
' source overflow [with unsigned byte] -> destination approximation
'
' 200 = 11001000 -> 01001000 -> +72
sb = 200
PRINT "signed byte(200) = "; sb; " (exp ";"72";" )"
' source overflow [with signed word] -> destination approximation
'
' -500 = 1111111000001100 -> 000111110100 -> 11110100 -> -116
sb = -500
PRINT "signed byte(-500) = "; sb; " (exp ";"-116";" )"
' source overflow [with unsigned word] -> destination approximation
'
' 20000 = 0100111000100000 -> 00100000 -> +32
sb = 20000
PRINT "signed byte(20000) = "; sb; " (exp ";"32";" )"
' source overflow [with signed dword] -> destination approximation
'
' -100500 = 11111111111111100111011101101100 -> 00011000100010010100 -> 10010100
sb = -100500
PRINT "signed byte(-100500) = "; sb; " (exp ";"-20";" )"
' source overflow [with unsigned dword] -> destination approximation
sb = 10020000
PRINT "signed byte(10020000) = "; sb; " (exp ";"32";" )"
' ******************************************************************
' ******************************************************************
' ******************************************************************
WAIT KEY RELEASE : PRINT
' ******************************************************************
' ******** destination: unsigned byte ******************************
' ******************************************************************
DIM b AS BYTE
' source underflow -> destination underflow
'
' 42 = 11010110 -> 11010110 -> 42
b = 42
PRINT "byte(42) = "; b; " (exp ";"42";" )"
' source overflow [with unsigned byte] -> destination unsigned
'
' -42 = 11010110 -> 01001000 -> +42
b = -42
PRINT "byte(-42) = "; b; " (exp ";"42";" )"
' source overflow [with signed word] -> destination approximation
'
' -500 = 1111111000001100 -> 000111110100 -> 11110100 -> -116
b = -500
PRINT "byte(-500) = "; b; " (exp ";"12";" )"
' source overflow [with unsigned word] -> destination approximation
'
' 20000 = 0100111000100000 -> 00100000 -> +32
b = 20000
PRINT "byte(20000) = "; b; " (exp ";"32";" )"
' source overflow [with signed dword] -> destination approximation
'
' -100500 = 11111111111111100111011101101100 -> 00011000100010010100 -> 10010100
b = -100500
PRINT "byte(-100500) = "; b; " (exp ";"148";" )"
' source overflow [with unsigned dword] -> destination approximation
b = 10020000
PRINT "byte(10020000) = "; b; " (exp ";"160";" )"
' ******************************************************************
' ******************************************************************
' ******************************************************************
WAIT KEY RELEASE : PRINT
' ****************************************************************
' ******** destination: signed word ******************************
' ****************************************************************
DIM sw AS SIGNED WORD
' source underflow -> destination underflow
'
' 42 = 11010110 -> 11010110 -> 42
sw = 42
PRINT "signed word(42) = "; sw; " (exp ";"42";" )"
' source underflow [with unsigned byte] -> destination underflow
'
' -42 = 11010110 -> -42
sw = -42
PRINT "signed word(-42) = "; sw; " (exp ";"-42";" )"
' source underfow [with signed word] -> destination underflow
'
' -500 = 1111111000001100 -> -500
sw = -500
PRINT "signed word(-500) = "; sw; " (exp ";"-500";" )"
' source overflow [with unsigned word] -> destination approximation
'
' 40000 = 0100111000100000 -> 00100000 -> 7232
sw = 40000
PRINT "signed word(40000) = "; sw; " (exp ";"7232";" )"
' source overflow [with signed dword] -> destination approximation
'
' -100500 = 11111111111111100111011101101100 -> 00011000100010010100 -> 10010100
sw = -100500
PRINT "signed word(-100500) = "; sw; " (exp ";"-2196";" )"
' source overflow [with unsigned dword] -> destination approximation
sw = 10020000
PRINT "signed word(10020000) = "; sw; " (exp ";"25760";" )"
' ******************************************************************
' ******************************************************************
' ******************************************************************
WAIT KEY RELEASE : PRINT
' ******************************************************************
' ******** destination: unsigned word ******************************
' ******************************************************************
DIM w AS WORD
' source underflow -> destination underflow
'
' 42 = 11010110 -> 11010110 -> 42
w = 42
PRINT "word(42) = "; w; " (exp ";"42";" )"
' source underflow [with unsigned byte] -> destination underflow
'
' -42 = 11010110 -> -42
w = -42
PRINT "word(-42) = "; w; " (exp ";"42";" )"
' source underfow [with signed word] -> destination underflow
'
' -500 = 1111111000001100 -> -500
w = -500
PRINT "word(-500) = "; w; " (exp ";"500";" )"
' source overflow [with unsigned word] -> destination underflow
'
' 40000 = 0100111000100000 -> 00100000 -> 7232
w = 40000
PRINT "word(40000) = "; w; " (exp ";"40000";" )"
' source overflow [with signed dword] -> destination approximation
'
' -100500 = 11111111111111100111011101101100 -> 00011000100010010100 -> 10010100
w = -100500
PRINT "word(-100500) = "; w; " (exp ";"30752";" )"
' source overflow [with unsigned dword] -> destination approximation
w = 10020000
PRINT "word(10020000) = "; w; " (exp ";"58528";" )"
' ******************************************************************
' ******************************************************************
' ******************************************************************
WAIT KEY RELEASE : PRINT
' *****************************************************************
' ******** destination: signed dword ******************************
' *****************************************************************
DIM dw AS SIGNED DWORD
' source underflow -> destination underflow
'
' 42 = 11010110 -> 11010110 -> 42
dw = 42
PRINT "signed dword(42) = "; dw; " (exp ";"42";" )"
' source underflow [with unsigned byte] -> destination underflow
'
' -42 = 11010110 -> -42
dw = -42
PRINT "signed dword(-42) = "; dw; " (exp ";"-42";" )"
' source underfow [with signed word] -> destination underflow
'
' -500 = 1111111000001100 -> -500
dw = -500
PRINT "signed dword(-500) = "; dw; " (exp ";"-500";" )"
' source underflow [with unsigned word] -> destination underflow
'
' 40000 = 0100111000100000 -> 00100000 -> 7232
dw = 40000
PRINT "signed dword(40000) = "; dw; " (exp ";"40000";" )"
' source underflow [with signed dword] -> destination underflow
'
' -100500 = 11111111111111100111011101101100 -> 00011000100010010100 -> 10010100
dw = -100500
PRINT "signed dword(-100500) = "; dw; " (exp ";"-100500";" )"
' source underflow [with unsigned dword] -> destination approximation
dw = 10020000
PRINT "signed dword(10020000) = "; sw; " (exp ";"25760";" )"
' ******************************************************************
' ******************************************************************
' ******************************************************************
WAIT KEY RELEASE : PRINT
' ******************************************************************
' ******** destination: unsigned word ******************************
' ******************************************************************
DIM udw AS DWORD
' source underflow -> destination underflow
'
' 42 = 11010110 -> 11010110 -> 42
udw = 42
PRINT "unsigned dword(42) = "; udw; " (exp ";"42";" )"
' source underflow [with unsigned byte] -> destination underflow
'
' -42 = 11010110 -> -42
udw = -42
PRINT "unsigned dword(-42) = "; udw; " (exp ";"42";" )"
' source underfow [with signed word] -> destination underflow
'
' -500 = 1111111000001100 -> -500
udw = -500
PRINT "unsigned dword(-500) = "; udw; " (exp ";"500";" )"
' source underflow [with unsigned word] -> destination underflow
'
' 40000 = 0100111000100000 -> 00100000 -> 7232
udw = 40000
PRINT "unsigned dword(40000) = "; udw; " (exp ";"40000";" )"
' source underflow [with signed dword] -> destination underflow
'
' -100500 = 11111111111111100111011101101100 -> 00011000100010010100 -> 10010100
udw = -100500
PRINT "unsigned dword(-100500) = "; udw; " (exp ";"-100500";" )"
' source underflow [with unsigned dword] -> destination underflow
udw = 10020000
PRINT "unsigned dword(10020000) = "; udw; " (exp ";"10020000";" )"
END PROCEDURE
example[] ON ALL BUT VIC20
SOURCE FILE
HOW TO COMPILE AND RUN
The instructions here refer to compiling the example from the command line. For Microsoft Windows users we suggest using 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 maths_relative_03.bas -o example.xex altirra example.xex # Windows ugbc.atari.exe maths_relative_03.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 maths_relative_03.bas -o example.xex altirra example.xex # Windows ugbc.atarixl.exe maths_relative_03.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 maths_relative_03.bas -o example.prg x64sc example.prg # Windows ugbc.c64.exe maths_relative_03.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 maths_relative_03.bas -o example.prg x64sc -reu example.prg # Windows ugbc.c64reu.exe maths_relative_03.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 maths_relative_03.bas -o example.prg yape example.prg # Windows ugbc.plus4.exe maths_relative_03.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 maths_relative_03.bas -o example.prg xplus4 example.prg # Windows ugbc.plus4.exe maths_relative_03.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 maths_relative_03.bas -o example.bin xroar -rompath (your rom path) example.bin # Windows ugbc.d32.exe maths_relative_03.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 maths_relative_03.bas -o example.bin xroar -rompath (your rom path) example.bin # Windows ugbc.d64.exe maths_relative_03.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 maths_relative_03.bas -o example.k7 dcmoto (choose BASIC 128) CLEAR,&H2FFF: LOADM"CASS:",R: EXEC # Windows ugbc.pc128op.exe maths_relative_03.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 maths_relative_03.bas -o example.k7 dcmoto (choose BASIC 128) CLEAR,&H2FFF: LOADM"CASS:",R: EXEC # Windows ugbc.pc128op.exe maths_relative_03.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 maths_relative_03.bas -o example.prg xvic --memory 24k example.prg # Windows ugbc.vic20.exe maths_relative_03.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 maths_relative_03.bas -o example.tap Speccy example.tap # Windows ugbc.zx.exe maths_relative_03.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 maths_relative_03.bas -o example.rom openmsx -cart example.rom # Windows ugbc.msx1.exe maths_relative_03.bas -o example.rom openmsx -cart example.rom
blueMSX
# Linux ugbc.msx1 maths_relative_03.bas -o example.rom bluemsx example.rom # Windows ugbc.msx1.exe maths_relative_03.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 maths_relative_03.bas -o example.rom openmsx -machine \"COL - ColecoVision\" -cart example.rom # Windows ugbc.coleco.exe maths_relative_03.bas -o example.rom bluemsx -machine \"COL - ColecoVision\" example.rom
blueMSX
# Linux ugbc.coleco maths_relative_03.bas -o example.rom bluemsx /machine \"COL - ColecoVision\" /rom1 example.rom # Windows ugbc.coleco.exe maths_relative_03.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 maths_relative_03.bas -o example.rom bluemsx /machine \"SEGA - SC-3000\" /rom1 example.rom # Windows ugbc.sc3000.exe maths_relative_03.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 maths_relative_03.bas -o example.rom bluemsx /machine \"SEGA - SG-1000\" /rom1 example.rom # Windows ugbc.sg1000.exe maths_relative_03.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, open an issue for this example on GitHub. Thank you!
POWERED BY
Page Tools
