Change logs of ugBASIC language

Main branch (cpc)

BETA ALL atarixl atari cocob coco coco3b coco3 coleco c128 c128z c16 c64 c64reu d32b d32 d64b d64 gb msx1 pc128op plus4 sc3000 sg1000 mo5 to8 vic20 zx

Learn to Write (Retro)Videogames! new sei italiano?
Learn to Write (Retro)Videogames! new sei italiano?
Embark on a journey into the (retro)programming of three simple video games, three "easy pieces", which will help you become familiar with some basic concepts, to apply them to computers with limited resources.

The purpose of this book, therefore, is not just to illustrate a source code: instead it offers ideas for actively developing the three easy pieces.

Programming while reading.
Learn to Write (Retro)Videogames! new sei italiano?
Embark on a journey into the (retro)programming of three simple video games, three "easy pieces", which will help you become familiar with some basic concepts, to apply them to computers with limited resources.

  • v1.18 [rev. 20251117] COLDFIX


    commit: fbbeab991 (on github)
    • Fixed asm code generation
    • Fixed byte constant generation under z80


  • v1.18 [rev. 20251116] COLDFIX


    commit: 5338a91d9 (on github)
    • Fixed color selection under cpc
    • Added support for embedded deployed
    • Fixed WAIT FIRE under cpc
    • Fixed file permission


  • v1.17.2 [rev. 20251020] COLDFIX


    commit: 5820bf506 (on github)
    • Fixed memory corruption on huge optimizations


  • v1.17.2 [rev. 20251011] COLDFIX


    commit: d9246259d (on github)
    • Fixed bitwidth adaption on division


  • v1.17.2 [rev. 20250715] COLDFIX


    commit: 3b396d2ee (on github)
    • Increased temporary space for error messages
    • Fixed volume set on sn-76489 on z80
    • Fixed frequency offset on AY-8910 music support under z80


  • v1.17.2 [rev. 20250706] COLDFIX


    commit: f98ba66ec (on github)
    • Fixed wrong warnings on gime and cpc


  • v1.17.2 [rev. 20250527] COLDFIX


    commit: 653b8bc9a (on github)
    • Fixed screen mode unique startup value on vic2


  • v1.17.2 [rev. 20250522] COLDFIX


    commit: 3157060cb (on github)
    • Removed unused variables (draw related)
    • Removed unused variables (fp related)
    • Removed unused variables (slice related)
    • Removed unused variables (blit related)
    • Removed unused variables (tiles related)
    • Removed unused variables (protothread related)
    • Removed unused variables (fp related)
    • Optimized space occupied by unused variables


  • v1.17.1 [rev. 20250512] COLDFIX


    commit: 92c0fdc86 (on github)
    • Fixed error messages for plus and minus signs
    • Fixed error messages for curly brackets


  • v1.17.1 [rev. 20250421] COLDFIX


    commit: 311f17084 (on github)
    • Fixed cpc build command line


  • v1.17.1 [rev. 20250417] COLDFIX


    commit: da8e2e161 (on github)
    • Fixed asm snippets emit in empty procedures


  • v1.17.1 [rev. 20250412] COLDFIX


    commit: 6281390f3 (on github)
    • More readable syntax errors


  • v1.17.1 [rev. 20250329] COLDFIX


    commit: 8fc054e3d (on github)
    • Fixed starting address on coco when given


  • v1.17.1 [rev. 20250326] COLDFIX


    commit: 2b3a760d5 (on github)
    • Fixed 16 bit signed multiplication under z80 and sm83
    • Fixed const definition
    • Fixed array access with byte index (big endian)


  • v1.17.1 [rev. 20250317] COLDFIX


    commit: 5fd9862db (on github)
    • Corrected negative floating number decoding


  • v1.17 [rev. 20250227] COLDFIX


    commit: 581cfa299 (on github)
    • Fixed signed best type calculation


  • v1.17 [rev. 20250225] COLDFIX


    commit: 558e7e39d (on github)
    • Fixed vertical scrolling under graphical mode on 6847


  • v1.17 [rev. 20250218] COLDFIX


    commit: 29a4a9636 (on github)
    • Fix string descriptor leak


  • v1.17 [rev. 20250207] COLDFIX


    commit: 45aa58697 (on github)
    • Optimization of PRINT under cpc #1184
    • Wrongly optimized code on Z80 #1192
    • Fixed maximum number of rows on cpc


  • v1.17 [rev. 20250202] HOTFIX


    for cpc commit: d1a33ecd8 (on github)
    • Compiler crash if RESTORE is used without DATA #1189


  • v1.17 [rev. 20250201] COLDFIX


    commit: d1d94fb14 (on github)
    • Fixed reset vars under msx1 when 10 liner is enabled
    • Fixed constant generation
    • Fixed buffer parsing
    • Fixed rle inclusion if not used


  • v1.17 [rev. 20250130] COLDFIX


    commit: 9c5271206 (on github)
    • Add bound check on statically accessed arrays


  • v1.17 [rev. 20250129] COLDFIX


    commit: 7e7f23cf8 (on github)
    • change graphics mode on CPC doesn't always work #1183
    • Sources code embedded must be readonly


  • v1.17 [rev. 20250128] COLDFIX


    commit: 3ad3d2a29 (on github)
    • Fixed startup console initialization (for 10 liners)


  • v1.16.5 [rev. 20250124] COLDFIX


    commit: 22cfb5315 (on github)
    • COLOR 0 problem (cpc) #1178


  • v1.16.5 [rev. 20250120] COLDFIX


    commit: cf483e48c (on github)
    • IDE crash when trying to use a non-global variable in an ASM block (z80) #1177
    • Fixed optimizer under z80


  • v1.16.5 [rev. 20250118] COLDFIX


    commit: c5484e4f1 (on github)
    • IDE crash when trying to use a non-global variable in an ASM block (z80) #1177


  • v1.16.5 [rev. 20250111] COLDFIX


    commit: 36492a504 (on github)
    • Fixed error message if compiler cannot open a file
    • Updated VERSION of z88dk


  • v1.16.5 [rev. 20250106] HOTFIX


    for cpc commit: 8f0823226 (on github)
    • Fixed DEFINE IMAGE FREE WIDTH support under cpc


  • v1.16.5 [rev. 20250104] COLDFIX


    commit: 90b332de5 (on github)
    • Wrong masking of border color under cpc (regression) #1165


  • v1.16.5 [rev. 20250102] COLDFIX


    commit: 01ede36b3 (on github)
    • Moved to 2025: new year, new possibilities!


  • v1.16.5 [rev. 20241230] COLDFIX


    commit: 09c27fc5d (on github)
    • Fixed entropy management on seed initialization for z80
    • Mask border color on 4 bit limitations (cpc)


  • v1.16.5 [rev. 20241226] COLDFIX


    commit: 1d9833910 (on github)
    • WAIT FIRE compile crash (cpc) #1139
    • VOLUME problem when using WAIT KEY (msx1 and cpc) #1140


  • v1.16.5 [rev. 20241224] COLDFIX


    commit: 6a7ef2c5e (on github)
    • Wrongly initialization of mode 1 under cpc #1126


  • v1.16.5 [rev. 20241220] HOTFIX


    for cpc commit: 7234534cb (on github)
    • Unexpected behaviour with RANDOM HEIGHT and RANDOM WIDTH #1115


  • v1.16.5 [rev. 20241215] COLDFIX


    commit: a2cb9253d (on github)
    • Startup palette fix on cpc #1097


  • v1.16.5 [rev. 20241212] COLDFIX


    commit: bf9a3b250 (on github)
    • Fixed directory not existent error in rebuilding if src-generated is missing


  • v1.16.5 [rev. 20241210] COLDFIX


    commit: 241c42eed (on github)
    • Unwanted trail on HSCROLL RIGHT (cpc) #1063
    • HSCROLL SCREEN LEFT has broken (cpc) #1082


  • v1.16.5 [rev. 20241209] COLDFIX


    commit: 883ea3153 (on github)
    • Unwanted trail on HSCROLL RIGHT (cpc) #1063


  • v1.16.5 [rev. 20241208] COLDFIX


    commit: 5d27a8a2f (on github)
    • Fixed disruptive optimization rule on z80


  • v1.16.5 [rev. 20241207] COLDFIX


    commit: 3272460a7 (on github)
    • Added support for explicit versioning of compilers


  • v1.16.5 [rev. 20241206] COLDFIX


    commit: 1e47b1060 (on github)
    • Atari XL Graphics 8 (320x192x2) - Y wraps around at 96px #1068
    • Unwanted trail on HSCROLL RIGHT (cpc) #1063


  • v1.16.5 [rev. 20241205] COLDFIX


    commit: eb7cb20b1 (on github)
    • IMAGES or DLOAD potential issue (cpc) #1054


  • v1.16.5 [rev. 20241203] COLDFIX


    commit: e78272d68 (on github)
    • Optimized descriptor retrieve for dynamic strings


  • v1.16.5 [rev. 20241202] HOTFIX


    for cpc commit: c6253b3fb (on github)
    • Wrong JOY FIRE (constant) #1059
    • INCLUDE command syntax unrecognized #1055
    • Wrong behaviour of INSERT after second line #1058
    • The keyword LCASE doesn't seems recognized (does not compile) #1060
    • LEFT (instruction) vs LEFT (function) manual problem #1061
    • Wrong example on LEFT ARROW (constant) #1062


  • v1.16.4 [rev. 20241130] COLDFIX


    commit: af54e7e94 (on github)
    • IMAGE function problem (cpc) #1053


  • v1.16.4 [rev. 20241126] COLDFIX


    commit: 97915f3f9 (on github)
    • Fixed 16 bit subctraction under z80
    • Fixed array access under z80


  • v1.16.4 [rev. 20241124] COLDFIX


    commit: 7ca2c8ff4 (on github)
    • Fixed character variable emission
    • Fixed MIDI program replacement if instrument is missing on score


  • v1.16.4 [rev. 20241119] COLDFIX


    commit: a3a7c03f5 (on github)
    • Fixed ppq and tick timing on MIDI>IMF decoding
    • Fixed conflict on zero page for keyboard detection under cia
    • Artefacts on low res scrolling under coco #1037


  • v1.16.4 [rev. 20241118] HOTFIX


    for cpc commit: 8a34d72ab (on github)
    • DIV command unsupported on FLOAT type #1034
    • Wrong DISTANCE result on z80 #1033
    • Fixed UBOUND maximum limit to base 0
    • Fixed n-bits copy for 6502


  • v1.16.4 [rev. 20241117] COLDFIX


    commit: d43cbd51c (on github)
    • Wrong color value for purple on cpc #1029
    • Fixed MIDI instrument decoding on multiple tracks


  • v1.16.4 [rev. 20241116] HOTFIX


    for cpc commit: bba330b7c (on github)
    • Clear seems not clearing variables correctly #1027
    • Issues on ellipse algorithm #986
    • PUT KEY issue (cpc) #994


  • v1.16.4 [rev. 20241115] HOTFIX


    for cpc commit: 4c3a7cb73 (on github)
    • Wrong color value for purple on cpc #1029


  • v1.16.4 [rev. 20241114] HOTFIX


    for cpc commit: 4a056d193 (on github)
    • Ghost keys with ASCIICODE on cpc #1017
    • Issues on ellipse algorithm #986


  • v1.16.4 [rev. 20241113] COLDFIX


    commit: a6ff91042 (on github)
    • PUT KEY issue (cpc) #994
    • ASTERISK problem (cpc) #1018
    • AT instruction (cpc) #1019
    • BAR issues (cpc) #1020
    • BIN issue (cpc) #1022
    • PUT KEY issue (cpc) #994


  • v1.16.4 [rev. 20241113] COLDFIX


    commit: e98d1cfa7 (on github)
    • Wrong duration of SOUND command on cpc #1002
    • Refactorized audio duration
    • Added support for division using constants
    • Added cpu division with const.
    • Unwinding stack on retrieving values on z80 #1014


  • v1.16.4 [rev. 20241111] COLDFIX


    commit: 1d1994fb6 (on github)
    • Wrong duration of SOUND command on cpc #1002
    • Conflict between F4 key and F4 note #1004
    • Added support for volume encoding in midi>imf converter (cpc)
    • VOLUME does not work under cpc #1005
    • MUSIC does not work under cpc #1009


  • v1.16.4 [rev. 20241110] HOTFIX


    for cpc commit: 9c1a4fa31 (on github)
    • Wrong duration of SOUND command on cpc #1002
    • Conflict between F4 key and F4 note #1004
    • Missing PLAY syntax as documented #1007
    • Added support for volume encoding in midi>imf converter (cpc)
    • VOLUME does not work under cpc #1005
    • MUSIC does not work under cpc #1009


  • v1.16.4 [rev. 20241109] COLDFIX


    commit: d993cbff0 (on github)
    • SOUND problem (cpc) #999
    • ASCIICODE problem (cpc) #998
    • PUT KEY issue (cpc) #994
    • CAPS LOCK issue (cpc) #992


  • v1.16.4 [rev. 20241109] COLDFIX


    commit: 2ae802ca4 (on github)
    • BLIT IMAGE problem (cpc) #990
    • error with AT command on cpc #972
    • CONSOLE command again (cpc) #979


  • v1.16.4 [rev. 20241107] COLDFIX


    commit: a576dee29 (on github)
    • BLIT IMAGE problem (cpc) #990


  • v1.16.4 [rev. 20241106] HOTFIX


    for cpc commit: fba7a648c (on github)
    • BLIT IMAGE problem (cpc) #990


  • v1.16.4 [rev. 20241104] HOTFIX


    for cpc commit: a576dee29 (on github)
    • CONSOLE command again (cpc) #979
    • CLINE error (cpc) #976
    • errors with CLEFT$ and CRIGHT$ on cpc #975
    • error with AT command on cpc #973


  • v1.16.4 [rev. 20241103] COLDFIX


    commit: c3f7be627 (on github)
    • Wrong color selection for cpc target #985
    • Unrespected left bound on clipping (cpc) #983
    • Issues on printing on mode 1 (cpc) #980
    • Error with CUP$ on cpc #974
    • CONSOLE command (cpc) #978
    • CONSOLE command again (cpc) #979
    • CLINE error (cpc) #976
    • Problem with MEMORIZE or REMEMBER (cpc) #977
    • Error with CDOWN$ on cpc #973
    • Strange behaviour with CMOVE on cpc #970
    • CMOVE documentation unclear (cpc) #971


  • v1.16.4 [rev. 20241101] HOTFIX


    for cpc commit: 03c95b641 (on github)
    • error with CDOWN$ on cpc #973
    • strange behaviour with CMOVE on cpc #970
    • CMOVE documentation unclear (cpc) #971


  • v1.16.4 [rev. 20241101] COLDFIX


    commit: 81f3d5aa2 (on github)
    • Fixed graphical position calculation under 6847


  • v1.16.4 [rev. 20241030] COLDFIX


    commit: 712010994 (on github)
    • SGN issue (cpc) #965
    • MAX and MIN error (cpc) #964
    • copying arrays compilation error (cpc) #963


  • v1.16.4 [rev. 20241030] HOTFIX


    for cpc commit: 712010994 (on github)
    • SGN issue (cpc) #965
    • MAX and MIN error (cpc) #964
    • copying arrays compilation error (cpc) #963


  • v1.16.4 [rev. 20241029] COLDFIX


    commit: 0c46ce141 (on github)
    • initialising a vector with no dimension (cpc) #961
    • issue with floats on cpc #955
    • BYTE type conversion on cpc #956
    • Fixed TAB parsing on cpc


  • v1.16.4 [rev. 20241029] HOTFIX


    for cpc commit: 0c46ce141 (on github)
    • initialising a vector with no dimension (cpc) #961
    • issue with floats on cpc #955
    • BYTE type conversion on cpc #956
    • INSTR error #959


  • v1.16.4 [rev. 20241028] HOTFIX


    for cpc commit: b0a8dfa46 (on github)
    • PAPER/PAPER$ functions don't work as intended on CPC #954
    • Fixed TAB parsing on cpc


  • v1.16.4 [rev. 20241027] COLDFIX


    commit: 35805c7dc (on github)
    • Fixed CR+LF in strings when printing
    • Fixed array assignment of dynamic strings


  • v1.16.4 [rev. 20241026] COLDFIX


    commit: 7ae04ad40 (on github)
    • Fixed filling color and irq management for ef936x scrolling
    • Fixed output for debugging on coco and coco3


  • v1.16.4 [rev. 20241024] COLDFIX


    commit: 40f5ea399 (on github)
    • Fixed IRQ management under plus4 (still testing)
    • Fixed PRINT at the end of the screen (cpc)
    • Fixed safe move when filenames matches


  • v1.16.4 [rev. 20241019] COLDFIX


    commit: db0794028 (on github)
    • Extend precision of trigonometric functions #756


  • v1.16.4 [rev. 20241016] COLDFIX


    commit: 065df43a5 (on github)
    • Contextual optimization on integer division with power of 2 divisor.


  • v1.16.4 [rev. 20241011] COLDFIX


    commit: 5be780371 (on github)
    • Fixed n-dimensional array access.


  • v1.16.4 [rev. 20241009] COLDFIX


    commit: af50c96a1 (on github)
    • Fixed error messages if wrongly called multithreaded instructions
    • Fixed floating point multiplication under z80
    • Optimized array access on writing (offset calculation)
    • Added CPU instruction cpu_store_8bit_with_offset2
    • Added support fot cpu_xor_const CPU instruction
    • Optimization: direct constant values passing on procedure calls
    • Fixed unread optimization rules for relative constants
    • Optimized access to limited monodimensional 1-byte arrays
    • Fixed unread optimization rules for relative constants
    • Added cpu_less_than_and_branch_8bit_const CPU instruction


  • v1.16.4 [rev. 20241006] HOTFIX


    for pc128op commit: 34804fc40 (on github)
    • Fixed optimization on 6809 code generation (A->B)
    • Fixed optimization on 6809 code generation (B->A)


  • v1.16.4 [rev. 20241004] COLDFIX


    commit: 3dff4d9a9 (on github)
    • Fixed cpu_indirect_call on z80 to preserve HL


  • v1.16.4 [rev. 20241002] HOTFIX


    commit: 05326f1a1 (on github)
    • Fix CLS under DEFINE DOUBLE BUFFER ON (pc128op).
    • Fixed KEY PRESSED / KEY STATE on multiple key press (pc128op)
    • Fixed screen vertical offset (c64, c64reu, c128)
    • Fixed SPRITE ENABLE / DISABLE with multiplexed sprites (vic2)
    • Fixed PRINT under multicolor bitmap vic2
    • Fixed disruptive optimization rules under 6502


  • v1.16.3 [rev. 20240921] HOTFIX


    commit: 39765312b (on github)
    • Fixed PUT IMAGE routines for multicolor mode under vic2
    • Fixed color detection for multicolor images under vic2
    • Fixed d64 image generation (c64, c64reu, c128)
    • Fixed PUT IMAGE under c64reu
    • Fixed loading banks from d64 on c64reu


  • v1.16.3 [rev. 20240906] COLDFIX


    commit: 23a0a080d (on github)
    • Fixed power of 2 division on z80


  • v1.16.3 [rev. 20240904] COLDFIX


    commit: db2c7b648 (on github)
    • Retro compatible hack: cocon_1163
    • Fixed division by power by 2 on z80
    • Fixed string tranpilation (memory allocation).
    • Fixed DATA generation for binary strings under cpc, c128, atari, atarixl.


  • v1.16.3 [rev. 20240827] COLDFIX


    commit: 1171bdfc9 (on github)
    • Increased available memory for parsing on compilers (10x factor)
    • Fixed star star (mul2) operator with variables


  • v1.16.3 [rev. 20240825] COLDFIX


    commit: ef4741a8e (on github)
    • Fixed memory exhausting re-using static strings (z80)


  • v1.16.3 [rev. 20240728] COLDFIX


    commit: 846693ccf (on github)
    • INPUT on Spectrum leaves cursor #914
    • Possible screen misalignment on C64? #915
    • Compiler crash for CoCo target #912
    • Scrolling broken for CPC target #913
    • Scroll causes weird chars to appear on Spectrum target #907


  • v1.16.3 [rev. 20240725] COLDFIX


    commit: 2fbb61e61 (on github)
    • Check correctness of temporary path #902
    • Fixed switch to text mode under vic2


  • v1.16.2 [rev. 20240715] COLDFIX


    commit: 8a8924d45 (on github)
    • Fixed constant emission in empty procedures


  • v1.16.2 [rev. 20240711] COLDFIX


    commit: f7645b137 (on github)
    • Fixed starting number of threads


  • v1.16.2 [rev. 20240702] COLDFIX


    commit: 58d1b91f7 (on github)
    • Fixed 6847 source code for 32 bit compilation
    • Fixed dynamic string garbage collection on z80


  • v1.16.2 [rev. 20240628] COLDFIX


    commit: 85537fd03 (on github)
    • BITMAP ENABLE without parameters is SCREEN #0 under cpc
    • Fixed CLINE under cpc
    • On Commodore targets missing label crashes IDE #798


  • v1.16.2 [rev. 20240627] COLDFIX


    commit: 5e857f0be (on github)
    • Added value on negative constant error (E071)


  • v1.16.2 [rev. 20240625] COLDFIX


    commit: 5889c4083 (on github)
    • Fixed FREE_STRING under z80


  • v1.16.2 [rev. 20240623b] COLDFIX


    commit: d96cd402a (on github)
    • Fixed z80_move_8bit_indirect under z80
    • Fixed image conversion on mode 1 on cpc
    • Fixed image color decoding on cpc chipset


  • v1.16.2 [rev. 20240619] HOTFIX


    commit: c1b65668d (on github)
    • Initialized to zero variables should be not reinitialized #788


  • v1.16.2 [rev. 20240617] COLDFIX


    commit: 84c844fe8 (on github)
    • Initialized to zero variables should be not reinitialized #788
    • Fixed image size asserts referred to frame width / height
    • Fix random number generator under z80


  • v1.16.2 [rev. 20240601] COLDFIX


    commit: 7cdc4b714 (on github)
    • Fixed CENTER instruction for CONSOLE support.
    • Fixed LOCATE instruction for CONSOLE support.


  • v1.16.1 [rev. 20240520] COLDFIX


    commit: cd09d1bc1 (on github)
    • Fixed array definition under cpc


  • v1.16.1 [rev. 20240505.0915] COLDFIX


    commit: ff5706865 (on github)
    • fixed DWORD to FLOAT conversion (signed)
    • fixed RND() on 32 bit values


Any problem?

If you have found a problem, if you think there is a bug or, more simply, you would like something to be improved, write a topic on the official forum, or open an issue on GitHub.
Thank you!