Latest VChar64 commit hash: c A D o u a m t t m h e i o : f t r i : x c : a R M c i o u a c n s 9 a e 1 r M 3 d a t 4 o r h 5 e d Q 1 1 u 4 c 7 e o 7 s 1 r d a 5 r e d : e d a 3 c 6 1 t b : 9 4 U b 1 R 8 L f 2 6 0 t a 1 o 8 6 a o d - p e 0 e a 7 n a 0 d 0 t c h 3 e 6 1 d 1 o a c 2 u 9 m e e n t a t i o n And this is how git describe shows it: ...
New version, new features. Download Mac: vchar64-0.0.12.dmg.zip Win32: vchar64-0.0.12.win32.zip Changes [NEW] Koala Import: supports importing subregions. Useful when 256 chars are not enough to import the whole bitmap [NEW] Added unknown font. Ripped from here [NEW] VICE snapshot import: Default charset address is the one that was used at the moment the snapshot was taken [NEW] Save/Export: Plays one beep on success, two beeps on error [NEW] Main Window: Status Bar shows the coordinates of the different widgets [BUGFIX] Export: shows correct extension when browsing file [BUGFIX] VICE/Koala Import: sets the name of the imported file in the tab [BUGFIX] Koala Import: detects duplicates chars, making the conversion smaller
VChar64 v0.0.10 is available for download: Mac: vchar64-0.0.10.dmg.zip Win32: vchar64-0.0.10.win32.zip Source code: Github repo Highlights: Live preview with the VChar64 TCP/IP Server for the C64 and C128 (in C128 mode) Minor bug fixes Full changelog: CHANGELOG v0.0.10
Let’s crack a simple game. If you are not familiar with Radare, read Part I first. Creating and opening a VICE Snapshot file Let’s crack BC’s Quest For Tires since its copy-protection is easy to bypass. Unzip this file: http://tapes.c64.no/tapes/BCsQuestForTires.zip Open the tap file with VICE (the most popular Commodore 64 emulator), and.. …the game has some kind of copy-protection. If we enter invalid codes, we won’t be able to play the game. Since Radare supports VICE Snapshot File format, we can save an snapshot of the game, and analyze it with Radare. In VICE, go to the menu, Snapshot -> Save Snapshot Image… If we select “Save ROMs”, then the BASIC ROM and the KERNAL ROM will be saved inside the Snapshot file, and will be included as Radare sections. Radare VICE Snapshot File (VSF) support lets us inspect: The 64k RAM of the computer at the moment the snapshot was saved The BASIC and KERNAL ROMs in case they were saved. To open a VSF file, just pass the VSF file as the first argument: $ [ 0 r x 2 0 0 b 0 c 0 _ 5 c 6 o 8 p 9 y ] _ > p r o t e c t i o n _ s c r e e n . v s f 0x00005689 is the PC (program counter) at the moment the snapshot was saved.
Cutting edge coding & debugging techniques:
VChar64 v0.0.9 is available for download: Mac: vchar64-0.0.9.dmg Win32: vchar64-0.0.9.zip Source code: Github repo Highlights: MDI support: Multiple open documents at the same time Copy & Paste tiles between documents even if they have different interleave options Bug fixes Full changelog: CHANGELOG v0.0.9
El amigo @SirArthur72 tiene un podcast de Commodore llamado Constelación Commodore. Es un podcast lleno de información de aquella época. En particular la sección “Bunkerpedia” es para escucharla varias veces, con toda la historia de Commodore, desde sus primeros inicios, hasta el final, lleno de detalles. Una particularidad del podcast, es que cada episodio dura más de 5 horas. En el último episodio (#8), se toca el tema de la C128, y aparezco yo en el podcast contando mis aventuras que tuve con esta linda computadora durante mi juventud. Aparezco alrededor de la hora 4:12 del podcast. ...
Radare is an open source portable reversing framework that can do many things, among those things it can disassemble 6502 code. Download and install radare First, download radare from github. You need a recent version in order to disassemble 6502 code. And then install it by running sys/install.sh (or sys/user.sh for local installation): $ $ $ g c i d / t s r y c a s l d / o a i n r n e e s 2 t h a t l t l p . s s : h / / g i t h u b . c o m / r a d a r e / r a d a r e 2 . g i t Loading a c64 .prg Radare has many command line options. But in order to load 6502 programs we need just two: -a6502 to specify the 6502 architecture. -mMemoryAddress to map the file to a certain memory address. Use 2047 for “normal” programs. Usually they start at $0801 (2049), but we have to subtract 2 from the .prg header. Example: $ r 2 - a 6 5 0 2 - m 2 0 4 7 m y g a m e . p r g Disassembling Radare doesn’t have a GUI, like IDA. Instead is has a powerful command line interface (think of GDB). Example: $ [ 0 r x 2 0 0 - 0 a 0 6 0 5 7 0 f 2 f ] - > m 2 0 4 7 m u s i c p l a y e r . p r g And 0x7ff (2047) is the seek address, meaning that all commands will use that address as the base address. Let’s print the first 32 bytes. ( px = print hexa): [ o 0 0 0 f x x x f 0 0 0 s 7 8 0 e f 0 0 t f f 0 0 7 0 0 f 0 1 d f 0 d ] 1 8 c > 0 a p 2 b 2 x 0 1 3 8 2 3 2 3 a 4 9 0 0 0 5 5 0 9 b 6 e 9 3 d 7 2 4 3 1 8 0 a 3 9 9 6 9 3 f A 1 0 0 2 B 0 0 0 c C 0 8 0 d D 0 0 7 f E 8 7 a c F d e 0 1 2 3 . 4 9 5 . 6 . 7 2 8 0 9 6 A 1 B . C . D . E x F . The “2061” that we see, is part of the BASIC “SYS 2061” command that usually appears in all C64 programs. So, let’s disassemble the first 12 instructions from 2061. ( pd = print disassemble): [ 0 x 0 0 0 0 0 ┌ │ │ └ 7 ┌ │ │ ─ │ │ │ └ f ─ ─ ─ f > < < ] > 0 0 0 0 0 0 0 0 0 0 0 0 x x x x x x x x x x x x p 0 0 0 0 0 0 0 0 0 0 0 0 d 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 8 8 8 8 8 8 8 8 8 8 8 8 @ 0 0 1 1 1 1 1 1 1 2 2 2 d e 1 3 5 8 b c e 1 4 5 2 0 6 1 7 a a a b 9 c d c c c d 8 d 2 0 9 9 8 0 e e a 0 0 1 0 d f f 1 1 e d 2 0 4 0 7 7 a e d 1 2 0 0 c a 0 8 8 s l l l l s i b d d d b e d d d d t n n e e e n i a x y a a y e c c x e 0 # # 0 0 0 0 0 0 x 0 0 x x x x x x d x x 1 2 f 0 0 e c 1 0 a 0 7 8 8 e 0 2 0 d f 1 1 d 4 0 7 a , , y y In case we don’t know the meaning of a certain opcode, we can print its description with ?d: [ s 0 e x t 0 0 i 0 n 0 t 0 e 8 r 1 r 5 u ] p > t ? d d i s s a e b i l e s t a t u s Or if we want to print the description in every disassembled line, we can do: e a s m . d e s c r i b e = t r u e And then disassemble again: [ ┌ │ │ └ 0 ─ ─ x > < 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 x x x x x x x x x x x x 0 0 0 0 0 0 0 0 0 0 0 0 0 0 8 8 8 8 8 8 8 8 8 8 8 8 8 0 0 1 1 1 1 1 1 1 2 2 2 0 d e 1 3 5 8 b c e 1 4 5 e ] > 7 a a a b 9 c d c c c d 8 d 2 0 9 9 8 0 e e a 0 p 0 1 0 d f f 1 1 e d d 2 0 4 0 7 7 a e d 1 2 0 0 1 c a 0 8 8 2 @ 2 0 s l l l l s i b d d d b 6 e d d d d t n n e e e n 1 i a x y a a y e c c x e 0 # # 0 0 0 0 0 0 x 0 0 x x x x x x d x x 1 2 f 0 0 e c 1 0 a 0 7 8 8 e 0 2 0 d f 1 1 d 4 0 7 a , , y y ; ; ; ; ; ; ; ; ; ; ; ; s l l l l s i b d d d b e o o o o t n r e e e r t a a a a o c a c c c a d d d d r r n r r r n i e e c e e e c n a i i a m h m m m h t c n n c a e e e e e c d d c c n o n n n o r u e e u c t n t t t n r m x x m u u u u m i r m m i r p l x y l u n e e e n e t a a l d s m m d s t w w t a e u o o e u d o i i o t x l r r x l i r t t r o t y y t s h h r y x a w w n b b n b i m m i i b o y y b o l t e e t n y t y t e h m m h o o o o m o z n n o z s m r r m e n e e e n e t e y y e m e r e r a m m o o o t o o r u r r y s y y For more disassembling options just type p?
VChar64 v0.0.8 is available for download: Mac: vchar64-0.0.8.dmg Win32: vchar64-0.0.8.zip Highlights: Import snapshots from VICE Tileset mode: Allows to preview all the tiles Better keyboard shortcuts …and many bug fixes. Full changelog: CHANGELOG v0.0.8
VChar64 v0.0.7 released. You can download it from here: Win32: vchar64-0.0.7.zip Mac: vchar64-0.0.7.dmg Tarball: vchar64-release-v0.0.7.zip Github: github.com/ricardoquesada/vchar64 New features: Added C64 Palettes: Pepto, VICE, CCS64, Frodo, Grayscale Copy + Paste using block selection Displays selected char on statusbar Ctrl+1, Ctrl+2, Ctrl+3, Ctrl+4 and Ctrl-M to select background, foreground, multicolor1, multicolor2 and Multicolor Mode Complete Changelog: CHANGELOG