#### Back to index | # Info for c64

#### Commodore 64

Diskette Usage:
Disk drives are simulated at the moment, and only file loads from drive 8 and 9
are implemented. You can load a program file from the rom directory (*.prg,*.p00)
You can also load a file from a d64 image (The directory command LOAD"$",8 is supported when
using d64 images).
Within the emulation, basic programs can be loaded with: LOAD"filename",8
Machine language programs can be loaded to their address with: LOAD"filename",8,1
When a program is loaded, type RUN or the appropriate SYS call to start it.
Note that several programs rely on more features not currently emulated (such as
loading other file types, writing...) Some games also rely on starting programs in the
floppy drive's processor (and therefore CPU level emulation of the 1541 is needed).

Cartridge Usage:
Cartridges may have any of the following extensions: .prg .crt .80 .90 .a0 .b0
.e0 .f0 Files with boot-sign in it are recognized as roms. Some cartridges may require more
than one image.
.prg files loaded at address in its first two bytes
.?0 files are loaded to the address specified in the extension.
.crt roms are loaded to the addresses specified in crt file.
Note that .prg files are assigned to the quickloader (so you have to use
the -cart switch when loading rom images).

Cassette Usage:
Cassette images with the .wav or .prg extensions as well as multiple .prg files
contained within a zip file can be loaded. Zip files must be placed in the current directory,
and the contained prg files are played in sequential order.
The format for WAVs are:
8 bit (16 bit may work, but hasn't been tested), mono, 12500 Hz minimum. This has the same
problems as an original Datasette tape drive (the tone head must be adjusted to get working
(no load error...) wav-files)
Note that tape volume is DAC1 volume within the MESS UI On Screen Display Options (accessed
with the tilde (~) key in the DOS version.
Within the emulation, use LOAD or LOAD"" or LOAD"",1 for loading normal programs. Use
LOAD"",1,1 for loading programs to a special address.

Quickloader Usage:
A quickloader is available via the f8 key. It supports program image files with
the .prg and .p00 extensions. This loads the program into memory and sets the program end
pointer. It works with most programs. The program can be started by entering "RUN" in the
emulation.

Miscellaneous Usage Notes:
Gameport A supports paddles 1 & 2, joystick 1, lightpen (implementation not finished).
Gameport B supports paddles 3 & 4, joystick 2
If you run into difficulty, be sure to start the emulation with the -log switch, and look into
the error.log file that is created in your mess directory.
If the game runs too fast with the NTSC version, try the PAL version! (c64pal)

Known Issues:
The rasterline based video system currently has the following issues: no CPU holding, imperfect
scrolling support (when 40 columns or 25 lines), lightpen support not finished, rasterline not
finished.
Sound is not currently supported
The restore key is not currently working.
NTSC/PAL select not correct.
The Gameports do not support the mouse (Serial Protocol?).
No printer or other devices support in the serial bus (apart from simple disk drives).
Simple tape support not working (cia timing?)
As far as expansion modules go, non-bankswitching rom cartridges (exrom) should work, but no
other rom cartridges (those with bankswitching logic in it, switching exrom, game). There is
no ieee488 support nor support for other expansion modules.
No userport support and no rs232/v.24 interface.
Some issues with the cia6526:
port a,b
handshake support, flag input, not pc output
no serial in/out, cnt
timer a,b
not counting of external clocks
not switching port b pins

History and Trivia:
Designed similar to the Vic-20, the Commodore 64 featured a better video chip supporting
sprites, as well as the famous sid6581 sound chip, two "Atari-compatible" joystick ports,
and 64 kilobytes of RAM.
The Commodore 64 is, along with the Apple II and the Atari 8-Bit computers, one of the
most famous home computers of it's era. During its production from 1982 to 1993 (!) 17
to 22 million (!) of these computer would sell, to put in perspective, that's more than
all the Macintoshes in the world. It was one of the first to offer a high quality sound
chip and graphic resolution with many colors and sprites. A great range of peripherals
was developed for this computer and can use several of the Vic 20 peripherals.
Several versions of the Commodore 64 were launched : The first one (C64-1) uses the VIC 20
case, it will be quickly replaced with the C64-2 which uses the famous brown case and by
the C64-3 with small cosmetic changes in the keyboard. A special version called Educator 64
or PET64 or CBM 4064 was proposed for schools and uses the PET case.
Commodore produced the first generation of C64s until May 1986, then it was discontinued
and they introduced the C64C. According to the 64'er magazine, this version has been
planned since the Hannover mass in 1985, but as the old version sold so well during
Christmas '85, its release date was pushed back.
The new model does not differ much from its predecessor, the only innovation is the
flatter case, which makes the keyboard (which has off-white keys now) more ergonomic
(it looks like the C128 case), as it is less higher than the old one. But the new case
did not only have advantages: due to its low profile and additional metal screening,
some of the numerous hardware expansions did not fit anymore. This was changed with
the C64G. The 64'er staff noticed that VIC-II as well as the two CIAs have new version
numbers; they didn't write which, though (these are probably just bugfixed chips).
The official name for this model was "C=64 C", but nevertheless the German 64'er magazine
decided to call it "C64-II" (because the first units didn't have the new name on the label
at the bottom), the badges on all the 64 C's just says "Commodore 64". They pointed out
that this name was only valid for the 64'er magazine, but since the 64'er was the
magazine for the C64 for a long time, the name was widely accepted and so this model
is mostly known as "C64-II" in Germany.
The C64C appeared again after (or concurrently with?) the C64G, this time with the new,
short board. So, although the case might look the same and the label says "Commodore 64",
the boards may be completely different.
Commodore also released a "laptop version" (though hardly portable) of the C64, called SX64.
This computer has a built-in 5" color screen, one detachable keyboard, one 5.25" floppy
disk drive (the famous 1541) and a second one can be installed as well. A version called
DX-64 was launched (in very limited quantities) at the same time, it has same
characteristics as the SX64 except its two 5.25" floppy disk drives. The SX64 and DX64
computers never had success, but it is known as the world's first color portable.
The C64GS was released in 1990. Basically it was a re-boxed C64, without a keyboard or any
other interfaces, except for the cartridge slot on top. It didn't have much success as you
could buy a C64 for not much extra, and the C64GS games would still work on the C64.
It came with one game cartridge containing International Soccer, Klax, Flimbo's Quest
and Fiendish Freddy's Big Top O'Fun. The carts had a memory of 4 megabits (512k).

created on Mon Dec 09 08:16:57 2002