THE ALE C64 EMULATOR
Version 1.13
_(C) Copyright 1992-1996 Andreas Arens, Lutz Sammer and Edgar Törnig_ Freely usable and freely distributable
CONTENTS [INLINE]
Emulator Documentation
Description
_ALE C64_ is a Commodore 64 emulator. _ALE C64_ is written in C.
The following ports exist.
- Linux (elf and a.out) with XFree86 (1.2,1.3 and 2.0)
- Linux (elf and a.out) with svgalib (1.2,1.3 and 2.0)
- SCO Unix with VGA console
- Solaris 2.4 for x86
- DOS with GO32 (32Bit DPMI code) Also runs under Win 3.1/3.11, Win95 and OS/2 in full screen mode.
_ALE C64_ can be copied and used absolute freely, but the copyright on the sources remains by the authors.
Installation
- Linux/Unix
- DOS
Linux/Unix:
Choose your installation directory
For example: /usr/games.
Unpack the archive
tar vxzf alec64-x.xx-elfbin.tar.gz
This is the ELF binary archive.
tar vxzf alec64-x.xx-aoutbin.tar.gz
This is the a.out binary archive.
x.xx is replaced by the version number.
Required shared libraries
I have compiled the binaries with the following shared libraries.
- Linux X11 ELF
+ libXext.so.6 (tested with 6.0) + libX11.so.6 (tested with 6.0) + libc.so.5 (tested with 5.2.18)
- Linux SVGALIB ELF
+ libvga.so.1 (tested with 1.2.10) + libc.so.5 (tested with 5.2.18)
- Linux X11 AOUT
+ libXt.so.6 (tested with 6.0) + libX11.so.6 (tested with 6.0) + libc.so.4 (tested with 4.7.2)
- Linux SVGALIB AOUT
+ libvga.so.1 (tested with 1.2.4) + libc.so.4 (tested with 4.7.2)
Build rom images
You need the image of the C64 BASIC ROM, C64 KERNEL ROM and C64 CHARACTER ROM to run the emulator. This images must be in the original binary form, exactly 8192 or 4096 bytes long, no extra information.
If you don't know how to get this images, read the comp.emulators.cbm FAQ. See also: C64-ROM-IMAGES
cat basic kernel character > romimage.c64
-or-
cat original.64b original.64k original.64c > romimage.c64
basic, kernel and character are the names of your ROM images.
If you want to use the fastloader support (real 1541 emulation) you also need the 1541 ROM images. This image must be in the original binary form, exactly 16384 bytes long.
mv yourrom 1541roms.c64
Rename your 1541 ROM image to "1541roms.c64"!
Choose the correct executable
_Note: video-sync versions have been folded into the other executables. It can be turned on using the -v commandline option. _
c64-svga-sp
C64 for svgalib with speaker.
c64-svga-o3
C64 for svgalib with opl3 support.
c64-svga-dsp
C64 for svgalib with dsp (sound-blaster) support.
c64-svga-os-sp
C64 for svgalib with overscan and speaker.
c64-svga-os-o3
C64 for svgalib with overscan and opl3 support.
c64-svga-os-dsp
C64 for svgalib with overscan and dsp (sound-blaster) support.
c64-x11-sp
C64 for X11 8bpp with speaker.
c64-x11-o3
C64 for X11 8bpp with opl3 support.
c64-x11-dsp
C64 for X11 8bpp with dsp (sound-blaster) support.
c64-x11-os-sp
C64 for x11 8bpp with overscan and opl3 support.
c64-x11-os-o3
C64 for X11 8bpp with overscan and opl3 support.
c64-x11-os-dsp
C64 for X11 8bpp with overscan and dsp (sound-blaster) support.
c64-x16-sp
C64 for X11 16bpp with speaker.
c64-x16-o3
C64 for X11 16bpp with opl3 support.
c64-x16-dsp
C64 for X11 16bpp with dsp (sound-blaster) support.
c64-x16-os-sp
C64 for x11 16bpp with overscan and opl3 support.
c64-x16-os-o3
C64 for X11 16bpp with overscan and opl3 support.
c64-x16-os-dsp
C64 for X11 16bpp with overscan and dsp (sound-blaster)
support.
ln "selected version" c64
-or-
ln -s "selected version" c64
Test it
You can now start the emulator with
c64
To exit press _ALT+SysReq (PRINT KEY)_.
- DOS
Choose your installation directory
For example: \games.
Unpack the archive
tar vxzf alec64-x.xx.tar.gz
or
unzip ale64xxx.zip
x.xx or xxx is replaced by the version number.
Build rom images
You need the image of the C64 BASIC ROM, C64 KERNEL ROM and C64 CHARACTER ROM to run the emulator. This images must be in the original form, exactly 8192 or 4096 bytes long, no extra information.
If you don't know how to get this images, read the comp.emulators.cbm FAQ. See also: C64-ROM-IMAGES
copy /b basic+kernel+character romimage.c64
-or-
copy /b original.64b+original.64k+original.64c romimage.c64
basic, kernel and character are the names of your ROM images.
If you want to use the fastloader support (real 1541 emulation) you also need the 1541 ROM images. This image must be in the original binary form, exactly 16384 bytes long.
ren yourrom 1541roms.c64
Rename your 1541 ROM image to "1541roms.c64"!
Choose the correct executable
_Note: video-sync versions have been folded into the other executables. It can be turned on using the -v commandline option. _
c64-sp
C64 version with speaker.
c64-o3
C64 version with opl3 support.
c64-sb
C64 version with dsp (sound-blaster) support.
c64-ossp
C64 version with VESA overscan and speaker.
c64-oso3
C64 version with VESA overscan and opl3 support.
c64-ossb
C64 version with VESA overscan and dsp (sound-blaster) support.
copy "selected version" c64.exe
Test it
You can now start the emulator with
c64
To exit press _ALT+SysReq (PRINT KEY)_. -or- To exit press _ALT+CTRL+DEL_. (obsolete)
Command line options
c64 [-1] [-2] [-a name] [-c dir] [-d disk] [-e name] [-f n] [-F n] [-g geometry] [-h] [-i roms] [-I roms] [-j] [-k input] [-l lib] [-q] [-r N] [-s] [-S] [-t N] [-u N] [-v N] [prgid]
- -1 Use keypad as Joystick 1. (Not supported under X11)
- -2 Use keypad as Joystick 2. (Not supported under X11)
- -a pathname Load the C64 file 'pathname' automatic at startup.
- -c path Change to the directory 'path' for the emulator.
- -d pathname Use floppy disk image (d64) 'pathname' as diskette.
- -e pathname Load the C64 image 'pathname' as external ROM.
- -f n Change the VIC fetch irq position to 'n'.
- -F n Change the VIC fetch read position to 'n' relative to irq position.
- -g geometry Geometry of the X11 window.
- -h Display a short help for command line options.
- -i pathname Use the ROM image 'pathname' as C64 ROMS.
- -I pathname Use the ROM image 'pathname' as 1541 ROMS.
- -j Enable hardware joystick.
- -k keyboard-input Keyboard input for the emulator. Letters, numbers and signs are converted to C64 character set. Don't forget to quote it correct! ('~' can be used for RET, and '^?' {ascii 127} for F7)
- -l pathname Use library file 'pathname' as database.
- -q Quiet, do no sound emulation.
- -r n Refresh rate, calculate/emulate only 1/n frames.
- -s Slow, means PAL fast-loader support. (You will see, what i mean :)
- -S Slow, means NTSC fast-loader support.
- -t N Timeout for cycle syncron fastloader. (in N/50 s)
- -u n Update rate, display only 1/n frames on X11.
- -v n Video sync the emulator to n% of the original c64. (100 or 0 is 1:1) _WARNING: This changes the DOS system-clock!!!!!_
- prgid Lookup 'prgid' in library database and start it. Use 'list' to show the contence of the library database.
Examples
c64 -1
Start c64 and use keypad as joystick 1.
Environment
You can use following environment variables to runtime configure _ALE C64_.
- C64LIB Use this file 'pathname' as library database.
- C64IMAGE Use this ROM image 'pathname' as C64 ROMS.
- C64EXROM Use this C64 ROM image 'pathname' as external ROM.
- C64AUTOLOAD Load this C64 binary file 'pathname' at startup.
- C64PRINTCMD Use this os program 'pathname' as printer filter. Not valid for DOS version.
- C64DIR Use this directory 'pathname' as working directory for C64. All releative paths are relative to this directory.
- R1541IMAGE Use this ROM image 'pathname' as 1541 ROMS.
- C64JOY1 Joystick port 1 configuration. (up,down,left,right).
Example: C64JOY1=693,1963,692,1952 (Linux), C64JOY1=50,110,50,110
(DOS).
* C64JOY1KEY
C64 key on joystick button 2. matrix_row8+matrix_column
Example: C64JOY1KEY=60 (SPACE).
C64JOY2
Joystick port 2 configuration. (up,down,left,right).
NOTE: Must be set to support second joystick.
* C64JOY2KEY
C64 key on joystick button 2. matrix_row8+matrix_column
Example: C64JOY2KEY=58 (CTRL).
C64TIMEOUT
Timeout for cycle syncron fastloader. (in N/50 s) This time the
1541 and C64 are hold cycle syncron. If a longer time no access to
serial happens, the 1541 emulation skips the emulation of this
cycles.
Examples
SH (Unix)
C64DIR=/usr/games/c64
export C64DIR
CSH (Unix)
setenv C64DIR /usr/games/c64
Uses the directory '/usr/games/c64' as start for relative paths. c64 -c psi-5 changes to the directory '/usr/games/c64/psi-5'.
DOS
set C64DIR=\games\c64
Uses the directory '\usr\games\c64' as start for relative paths. c64 -c psi-5 changes to the directory '\games\c64\psi-5'.
Keyboard
Keyboard layout used for emulation. I use a layout very simular to the original layout.
Picture keyboard layout
<- 1! 2" 3# 4$ 5% 6& 7' 8( 9) 0 + - __DEL_ CTRL q w e r t y u i o p q * RET_ RUN STOP a s d f g h j k l :[ ;] = RET SHIFT °1 z x c v b n m ,< .> /? RIGHTSHIFT CTRL C= |_________SPACE_________| C= FIRE
°1 is arrow-up and pi. On 101 keyboards use PAGE-DOWN.
The following keys have a special meaning for _ALE C64_.
Keys used for C64
F1 F2 F3 F4 F5 F6 F7 F8
The C64 functions keys
Caps-Lock
RUN/STOP
Left shift
LEFT SHIFT
Right shift
RIGHT SHIFT
Left Alt and Right Alt
C=
Left control and TAB (Right control is no longer C64 CTRL!!)
CONTROL
Home
HOME
End
RESTORE
Delete and Backspace
DEL
Insert
SHIFT DEL
Page up
POUND
Page down
UP-ARROW and PI
Arrow keys
The C64 cursor keys
Keys used for the emulator
F9
Decrements VicFetch the VIC fetch irq position.
SHIFT + F9
Increments VicFetch the VIC fetch irq position.
F10
Decrements VicFetchAdd the VIC read position relative to irq
position.
SHIFT + F10
Increments VicFetchAdd the VIC read position relative to irq
position.
F11
Toggles the sound emulation on/off
F12
Enters the builtin machine monitor
Toggle autofire on/off
SCROLL-LOCK
Change update rate ( 1 ->2 ->3 ->4 ->1 )
SHIFT + SCROLL-LOCK
Change emulation rate ( 1 ->2 ->3 ->4 ->1 )
PAUSE
Pause the emulator
NUM-LOCK
Toggles emulation of joystick 1 or 2
Keypad 1 2 3 4 6 7 8 9
Joystick direction
Keypad 5 and ESC
Joystick fire (ESC can have Autofire, Keypad-5 never)
Right control
Joystick fire with autofire
Keypad +
Change to next disk
Keypad -
Change to previous disk
Keypad *
Toggle fastloader ON PAL -> ON NTSC -> OFF.
Alt-Ctrl-Print, SysRequest
Leave emulator.
Alt-Ctrl-Delete
Leave emulator. (DOS, now obsolete!)
Ctrl-Pause, Intr.
Reset emulator.
Joystick
The joysticks of the C64 are emulated with the keyboard or hardware joystick.
Hardware Joystick
You can use an analog or digital PC joystick. I suggest a digital only PC joystick.
Install (LINUX)
You must have installed the joystick module. (Tested with 0.8.0)
Compile and run util/joycal.c. (Follow the given instructions). Setup following environment variable:
C64JOY1=up,down,left,right
export C64JOY1
Replace up, down, left and right with the values of the program.
You can now enable the joystick support with the commandline option -j.
Install (DOS)
Use a program which displays your joystick values.
Setup following environment variable:
set C64JOY1=up,down,left,right
Values below up,left are taken as up,left. Values above down,right are taken as down,right.
Use the second button
You can assign a C64-key to the second joystick button. The default is SPACE.
C64JOY1KEY=key -or- C64JOY2KEY=key
key is matrix_row*8+matrix_column
Table 1. Keyboard matrix table
Column
Row 0 1 2 3 4 5 6 7
0 | DEL | RET | | | | F7 | | F1 | | F3 | | F5 | | ^v |
1 | 3 | W | | A | | 4 | | Z | | S | | E | | SHL |
2 | 5 | R | | D | | 6 | | C | | F | | T | | X |
3 | 7 | Y | | G | | 8 | | B | | H | | U | | V |
4 | 9 | I | | J | | 0 | | M | | K | | O | | N |
5 | + | P | | L | | - | | . | | : | | @ | | , |
6 | PFN | * | | ; | | HOM | | SHR | | = | | ^ | | / |
7 | 1 |
If you want SPACE the value is 60. (row=7,column=4, 7*8+4 -> 60)
if you want CTRL the value is 58. (row=7,column=2, 7*8+2 -> 58)
- Notes
- The shown messages "Joystick 1" and "Joystick 2" always mean the keyboard.
Keyboard
- ESC (Escape) Joystick fire (repeated with AUTOFIRE).
- Right Control Joystick fire (repeated with AUTOFIRE).
- Keypad 1 Joystick down and left.
- Keypad 2 Joystick down.
- Keypad 3 Joystick down and right.
- Keypad 4 Joystick left.
- Keypad 5 Joystick fire (_not_ repeated with AUTOFIRE).
- Keypad 6 Joystick right.
- Keypad 7 Joystick up and left.
- Keypad 8 Joystick up.
- Keypad 9 Joystick up and right.
You can control the joystick emulation with:
- Num-lock Toggles joystick 1 or 2 emulation.
- PRINT Toggles autofire on or off (PAL: 25Hz or NTSC: 30Hz).
- Commandline: -1 Keypad emulates joystick port 1. (not under X11)
- Commandline: -2 Keypad emulates joystick port 2. (not under X11)
- Commandline: -j
Enable support for hardware joysticks.
- Note
- Under X11 the joystick emulations depends of the num-lock state.
CPU MOS 6510
The opcodes counts cycles and all hardware timings are calculate at this
base.
Supported features
- All opcodes are supported
- All addressing modes
- Peripheral port at $0/$1
- All illegal opcodes
- Memory wrap
- ($FF),Y and ($FF,X) bug
- jmp ($xxFF) bug
- Read-Modify-Write bug: write first unmodified data, then modified
- Correct cycles for branches page boundary crossing
Missing features
- Some features of the decimal mode.
- Test illegal 6510 opcodes (I didn't know, if all are correct emulated)
- Correct cycles for page boundary crossing (AX, AY, IY)
- Bug of 6510: Illegal read of indexed addressing
Extensions to 6510
We have extended the 6510 instruction set with emulator traps.
We need them to emulate the IEC serial routines.
You can use the emulator traps $09 - $11 to patch fastloader. Look at my example for 7 cities of gold.
- EMU #00 ($02 $00) Exit emulator.
- EMU #01 ($02 $01) Kernal patch: IEC TALK.
- EMU #02 ($02 $02) Kernal patch: IEC SECTALK.
- EMU #03 ($02 $03) Kernal patch: IEC UNTALK.
- EMU #04 ($02 $04) Kernal patch: IEC READ.
- EMU #05 ($02 $05) Kernal patch: IEC LISTEN.
- EMU #06 ($02 $06) Kernal patch: IEC SECLISTEN.
- EMU #07 ($02 $07) Kernal patch: IEC UNLISTEN.
- EMU #08 ($02 $08) Kernal patch: IEC WRITE.
- EMU #09 ($02 $09) IEC TALK: Serial send ACCU with talk. (without $40)
- EMU #0A ($02 $0A) IEC SECTALK:Serial send ACCU with sec. talk.
- EMU #0B ($02 $0B) IEC UNTALK: Serial send untalk.
- EMU #0C ($02 $0C) IEC READ: Read a byte from serial into ACCU.
- EMU #0D ($02 $0D) IEC LISTEN: Serial send ACCU with serial. (without $20)
- EMU #0E ($02 $0E) IEC SECLISTEN:Serial send ACCU with sec. listen.
- EMU #0F ($02 $0F) IEC UNLISTEN:Serial send unlisten.
- EMU #10 ($02 $10) IEC WRITE: Serial send ACCU.
- EMU #11 ($02 $11) IEC STATUS: Fetch serial status. (EOF...)
SID MOS 6581 or 8580
We support emulations of the SID for 3 different hardwares.
- PC Speaker
- DSP 8bit sampled data
- OPL2/OPL3 FM synth chip
PC Speaker
This was very easy to implemented and makes a good sound. In each
vertical retrace the SID emulation is called, 50 or 60 times per
second.
Each frame a different voice is emulated.
LINUX: I need I/O privileges to use the speaker.
(ALE C64 must be run as root or must have suid root rights!)
Disadvantage
No exact emulation.
DSP 8bit sampled data
The SID sound is sampled with 22050 Hz and played using '/dev/dsp' under
Linux or by direct hardware programming under DOS.
This gives you an exact emulation of the SID.
Supported features
* All waveforms:
+ Triangle
+ Sawtooth
+ Pulse
+ Noise
* Combine of waveforms.
* Pulse width.
* Envelopes (Attack, Decay, Sustain, Release).
* Main volume.
* Digital samples through D41C.
* Synchronize of voices. (SYNC-bit)
* Ring modulation. (RING-bit)
Missing features
* Filters. (I know how to build digital filter, but haven't the time
to write it.)
* Lockup of noise.
Disadvantage
If you have a slow computer, you hear clicks. (Use SCROLL-LOCK or
SHIFT-SCROLL-LOCK to speedup emulation)
OPL2/OPL3 FM synth chip
I convert the writes to the SID register to writes to opl2/opl3.
Does anybody know how to do the puls-width-modulation with an opl3? (mail to johns98@gmx.net)
LINUX: I need I/O privileges to use the opl3 chip.
(ALE C64 must be run as root or must have suid root rights!)
Supported features
* All waveforms. (Only with OPL3)
+ Triangle
+ Sawtooth
+ Pulse (Only pulse width of 50%)
+ Noise
* Envelopes (Attack, Decay, Sustain, Release)
* Main volume.
* Digital samples through D41C.
Missing features
* Synchronize of voices. _Need better docs, how I can do this with
OPL_
* Ring modulation. _Need better docs, how I can do this with OPL_
* Filters.
* Lockup of noise.
* Correct pulse width.
* Combine of waveforms.
Disadvantage
* The timings (Attack,...) and envelops are not exact emulated.
* Bad output of sampled data.
Control the SID emulation
- Commandline: -q Turns sound emulation off.
- Keyboard: F11 Toggles sound emulation on/off.
VIC II MOS 6567 (NTSC) or 6569 (PAL)
The VIC is implemented on a rasterline basis. This means every 63-65
cycles the 6510 emulation is stopped and a display line is drawn.
Supported features
- All video modes
+ Normal text mode + Multicolor text mode + Extended color text mode + Normal bitmap mode + Multicolor bitmap mode + Illegal modes Gives a black display.
- Complete sprite emulation
+ Normal sprites + Multicolor sprites + X and Y size doubling + Sprite-Sprite and Sprite-Background collision and interrupts + Sprite priority + Multiplexed sprites
- 38 or 40 columns mode
- 24 or 25 lines mode
- Splitscreens
- Raster interrupts
- Open vertical borders
- 26 text line mode
- Blank mode
- X and Y smooth scroll register
- Cycle stealing for bad-lines and sprites
- Idle state (VIC displays the contents of $3FFF of the current video bank)
- FLD (flexible line distance)
- FLI (flexible line interpretation)
- Linecrunch
- Dynamic X scrolling (creature 1 uses it)
Missing features
- No sprite collision, if sprite isn't visibile.
- Cycle stealing, if sprites not visibile.
- 100% correct cycle stealing (BA ignores writes).
- In line modifications.
- The correct line fetch position.
- Sprite stretching.
- Sprites in the left or right border.
Internals of VIC emulation
video-sync
The
_ALE C64_ Emulator runs with a virtual cpu clock, all hardware
timings depends on the virtual cpu clock. If you have a fast computer (486DX4/100 or better) the emulator is way to fast. To reduce it to the original speed, I use video-sync. This means each video frame is syncronised to 1/50s (PAL) or 1/60s (NTSC).
(Note: If you use the DSP sid emulation this is done by the sound driver!)
vic-fetch
The original c64 displays a video line over a long time (63-64us) one
pixel after the other. The emulator displays the complete line at a
specified cycle. I call this position vic-fetch. vic-fetch
are the cycles from the raster-line-irq to the emulator display.
vic-fetch-add
vic-fetch-add are the cycles from the raster-line-irq to the change
of the VIC rasterline register.
Control of the VIC emulation
- Commandline: -f n Change the VIC fetch irq position to 'n'.
- Commandline: -F n Change the VIC fetch read position to 'n' relative to irq position.
- Commandline: -v n Video sync the emulator to n% of the original c64. (100 or 0 is 1:1)
- Commandline: -r n Refresh rate, calculate/emulate only 1/n frames.
- Commandline: -u n Update rate, display only 1/n frames under X11.
- Keyboard: F9 Decrements the VIC fetch irq position.
- Keyboard: SHIFT + F9 Increments the VIC fetch irq position.
- Keyboard: F10 Decrements the VIC fetch read position relative to irq position.
- Keyboard: SHIFT + F10 Increments the VIC fetch read position relative to irq position.
- Keyboard: SCROLL-LOCK Change update rate ( 1 ->2 ->3 ->4 ->1 )
- Keyboard: SHIFT + SCROLL-LOCK Change calculation/emulation rate ( 1 ->2 ->3 ->4 ->1 )
Floppy Emulation
The Floppy supports both filesystem and disk image emulation. The
filesystem emulation supports both raw binary data and P00 format files.
Since c64 file names can include characters that are illegal on most filesystem, and that can be longer then the DOS 8.3 format, the P00 format is prefered for the filesystem emulation. Directories in the filesystem appear as a file of type DIR in the directory emulation, files too large to fit into to 16 bit block size appear as a file of type BIG with a size of 0. The filesystem supports a mixed mode. Both raw binary data and P00 files can reside in the same directory and will be autodected and used correctly according to their format. The filesystem emulation by default creates new files in P00 format.
Many games can be converted to raw binary (LINUX) or P00 format. I use 64copy to do this. (You can use 64copy with dosemu under LINUX)
You can change the directory or image for the 1541 emulation with
- 1541 command "G:directory", or "G:..", etc.
- Commandline: -c directory
- Monitor: w directory
- Keyboard: KEYPAD +, increment last number of disk image.
- Keyboard: KEYPAD -, decrement last number of disk image. The 1541 command "G:" can also be used to 'mount' disk images. If the selected directory in fact is a disk image (D64 file), the emulation is switched from filesystem to disk image mode. You can also do so from the monitor using the 'w' command or the '-c' commandline option. To 'unmount' you of course can use the "G:" command (1541) or 'w' command (monitor) again by changing to another directory or disk image (i.e. "G:." for the current directory).
Note: If you have to switch disks (disk images in fact) within a game, you of course cannot use the "G:" command over the 1541 command channel, but yo u
can still use the F12 to enter the monitor, switch images using the 'w' command, and then continue the game with the 'c' command.
1541 hardware emulation for fastloaders
For fastloaders a complete 1541 hardware emulation is needed. This means
the 6502 cpu, ports and serial lines.
I have just started the fastloader support, currently only 70% of the fastloaders may work.
My 1541 emulation only need processor time while loading.
Most games the first part could be loaded without fastloader. Than turn it on with KEYPAD *.
Supported features
* Works with PAL and NTSC fastloaders.
* Full 6502 emulation.
* All Jobs.
* Lowlevel moving head.
* Lowlevel GCR read.
* 99% cycle aligned 1541 <-%gt; C64.
Missing features
* GCR write. (formating, and low-level writes)
* Write protect.
* Exact timers.
* Memory mirrors. (need docs!)
Note
I didn't use a syncron 1541 emulation (every n c64 cylces, m 1541
cylces
are calculated
I use an asyncron 1541 emulation, if the c64 accesses the serial line the 1541 emulation calculates the missing cycles. If a longer time no access happends, this recalculation is skipped. (If you play 10 minutes, you don't want to wait minutes until the 1541 emulation has calculated the missing cycles.) You can control this timeout with the variable C64TIMEOUT.
Extensions
Extensions to the normal C64 hardware.
ALE-RAM
We have build into our C64 1K of additional RAM.
- 512 bytes at $D200-$D3FF.
- 512 bytes at $D600-$D7FF.
Some programs use the mirrored registers of the VIC ($D000-$3FFF)
or
SID ($D400-$D7FF) to fool the people.
You can disable this extensions with:
- Commandline: -x
Monitor
_ALE C64_ has a built in machine language monitor.
You can disassemble, display and modify the C64 memory.
You can enter the builtin monitor with 'F12'.
This are the builtin commands.
- ? Show all monitor commands.
- @ Show 1541 status.
- a [from] [to] Ascii dump.
- b [addr] Set breakpoint to "addr". Or show current breakpoint.
- B Unset breakpoint.
- c [break] Continue with emulation. (Optional breakpoint)
- C [break] Continue with emulation without display. (Optional breakpoint)
- d [from] [to] Disassemble.
- D [from] [to] Disassemble 1541 memory.
- e addr n1 [n2 ... nn] Edit memory.
- f [from] [to] [with] Fill memory.
- g [pc]. Go to emulation mode with pc.
- m [from] [to] Memory dump.
- M [from] [to] Memory dump of 1541 memory.
- r Register dump of the 6510.
- R Register dump of the 1541 6502 registers.
- w [directory_or_image] Change working directory or disk image of the 1541 emulation. Or show current working directory or disk image.
- X eXit _ALE C64_ emulator.
- FIXME: more to document.
_
Don't wonder with breakpoints enabled the emulator is 1/2 to 1/3 slower !!
_
Utilties
I have written some utilities to make the life easier.
bin2p00
Converts ALE C64 binary format to p00 format.
Files
This are the files used by the emulator.
/etc/default/c64 -or- alec64rc
The _ALE C64_ default settings.
1541roms.c64
Combined ROM images of the 1541.
autoload.c64
C64 file loaded automatically at start of the emulator.
external.c64
The external cartridge ROM image.
lib.c64
The C64 program library base.
romimage.c64
Combined ROM images of the C64.
snapshot.c64
Snapshot image.
dirfile.c64
Contains mapping of operating system file names to C64.
File formats
/etc/default/c64 The ALE C64 default settings
Is a ascii file, which contains the default settings for the emulator.
Or you can use the file alec64rc in C64DIR.
Each line has an entry:
VARIABLE=VALUE
VARIABLE
The same names as for the environment variables.
VALUE
The same values as for the environment variables.
Examples
#
# /etc/default/c64
#
# C64DIR should be absolute
C64DIR=/usr/local/games/lib/c64
# All others may be relative to C64DIR
C64IMAGE=romimage.c64
C64AUTOLOAD=prgs/util/mon$c
C64LIB=lib.c64
#C64PRINTCMD=lp -s -R %s
1541roms.c64 1541 ROM Images
8192 Bytes Floppy ROM $C000-$DFFF
8192 Bytes Floppy ROM $E000-$FFFF
romimage.c64 C64 ROM Images
8192 Bytes Basic ROM $A000-$BFFF
8192 Bytes Kernel ROM $E000-$FFFF
4096 Bytes Character ROM $C000-$DFFF
lib.c64 The ALE program library base
This is an ascii library database for easy access of C64
programs.
Each line has 3 entries:
program-id directory command
Separate the fields with tabs.
program-id
Name of the program for commandline
directory
Directory to enter before the start of game (relative to
C64DIR)
Could also be a disk-image.
command
C64 commands (keyboard input) to start the game. Letters,
numbers and signs are converted to C64 character set. ('~' can
be used for RET, and '^?' for F7)
Examples
# My games
# program-id directory command to start it
BlueMax games/synapse load"blue max",8,1~run~
SuperSprint tested/super_sprint load"loader",8,1~run~^?b
You can now start the games with:
c64 BlueMax
or
c64 SuperSprint
or even shorter:
Rename c64 or c64.exe to the program-id.
dirfile.c64 Filename conversion (obsolete)
os-name
type "c64-name"
os-name
Is the operating system filename. (for DOS 8 character + 3
extension)
type
Is the C64 type of the file ( prg, seq, usr or del ).
"c64-name"
Is the C64 file name enclosed in double quotes.
Examples
# Disk 2001
sprites prg "sprites"
name.c64 prg "a name with space"
ALE binary CBM files
ALE C64 uses the standard CBM program files containing load
address in the first two bytes.
Attributes are used to support the different C64 file types.
READ-ONLY
"set UID bit (UNIX)
"SEQ" 1541 sequential file.
set GID bit (UNIX)
"USR" 1541 user file.
set UID bit and set GID bit (UNIX)
"REL" 1541 relative file. (not supported, reserved)
no read bits and no write bits
"DEL" 1541 deleted file.
*.p00, *.s00, *.u00, *.d00, *.r00 Encapsulate C64 File Images.
These are C64 files prepended with a binary header to encapsulate
the file name so that it can be used on all filesystems.
Filename convention
*.p00
PRG program data file
*.s00
SEQ sequential data file
*.u00
USR user data file
*.d00
DEL deleted data file
*.r00
REL relative data file (Not supported by _ALE C64_)
00 can be any number, used to prevent the 16 to 8 name conversion
from generating duplicates.
* can be an up to 8 characters long filename, with the characters
in the range 64 to 95 ('@' - '_') and 48 to 57 ('0' - '9'.
Header format
Offset Bytes Description
------ ----- -----------------------------------
0 8 String "C64File" terminated by 00.
8 17 Original C64 Filename (in C64 character set).
25 1 Record size for REL files.
26 varies Original file image with load address.
*.d64 Raw 1541 disk Images.
This files contains all sectors as they appear on a standard 1541 formatted disk. Each sector is 256 bytes long. Error information (1 byte per sector can be added at the end of the file.
File types supported
* 174848 Bytes: 35 Tracks 683 Sectors
* 175531 Bytes: 35 Tracks 683 Sectors with error information
* 196608 Bytes: 40 Tracks 768 Sectors
* 197376 Bytes: 40 Tracks 768 Sectors with error information
* 205312 Bytes: 42 Tracks 802 Sectors
* 206114 Bytes: 42 Tracks 802 Sectors with error information
Track and Block Format
+--------------+-------------+-------------+ | TRACK NUMBER | BLOCK RANGE | TOTAL BLOCK | +--------------+-------------+-------------+
| 1 to 17 | 0 to 20 | 21 |
| 18 to 24 | 0 to 18 | 19 |
| 25 to 30 | 0 to 17 | 18 |
| 31 to 35 | 0 to 16 | 17 |
| 36 to 42 * | 0 to 16 | 17 |
+--------------+-------------+-------------+
- Tracks 36 to 42 are non standard.
Error codes for error information
CODE MEANING DOS ERROR MESSAGE
$01 Everything OK 00, OK
$02 Header block not found 20, READ ERROR
$03 SYNC not found 21, READ ERROR
$04 Data block not found 22, READ ERROR
$05 Checksum error in data block 23, READ ERROR
$07 Verify error 25, WRITE ERROR
$08 Disk write protected 26, WRITE PROTECT ON
$09 Checksum error in header block 27, READ ERROR
$0B Id mismatch 29, DISK ID MISMATCH
$0F Disk not inserted 74, DRIVE NOT READY
Error codes 06 and 0A do not occur on the 1541.
Original C64 Documentation
CPU MOS 6510
VIC II MOS 6567 (NTSC) or 6569 (PAL)
Table 1. VIC Register Map
SID MOS 6581 or 8580
SID CONTROL REGISTERS
There are 29 eight-bit registers in SID which control the generation of sound. These registers are either WRITE-only or READ-only and are listed below in Table 1.
Table 1. SID Register Map
REG # DATA REG NAME TYPE
(Hex) d7 d6 d5 d4 d3 d2 d1 d0
- --------------------------------------------------------------------
Voice 1:
00 F7 F6 F5 F4 F3 F2 F1 F0 FREQ LO Write
01 F15 F14 F13 F12 F11 F10 F9 F8 FREQ HI Write
02 PW7 PW6 PW5 PW4 PW3 PW2 PW1 PW0 PW LO Write
03 - - - - PW11 PW10 PW9 PW8 PW HI Write
04 NSE PUL SAW TRI TEST RING SYNC GATE CONTROL Write
05 ATK3 ATK2 ATK1 ATK0 DCY3 DCY2 DCY1 DCY0 ATK/DCY Write
06 STN3 STN2 STN1 STN0 RLS3 RLS2 RLS1 RLS0 STN/RLS Write
Voice 2:
07 F7 F6 F5 F4 F3 F2 F1 F0 FREQ LO Write
08 F15 F14 F13 F12 F11 F10 F9 F8 FREQ HI Write
09 PW7 PW6 PW5 PW4 PW3 PW2 PW1 PW0 PW LO Write
0A - - - - PW11 PW10 PW9 PW8 PW HI Write
0B NSE PUL SAW TRI TEST RING SYNC GATE CONTROL Write
0C ATK3 ATK2 ATK1 ATK0 DCY3 DCY2 DCY1 DCY0 ATK/DCY Write
0D STN3 STN2 STN1 STN0 RLS3 RLS2 RLS1 RLS0 STN/RLS Write
Voice 3:
0E F7 F6 F5 F4 F3 F2 F1 F0 FREQ LO Write
0F F15 F14 F13 F12 F11 F10 F9 F8 FREQ HI Write
10 PW7 PW6 PW5 PW4 PW3 PW2 PW1 PW0 PW LO Write
11 - - - - PW11 PW10 PW9 PW8 PW HI Write
12 NSE PUL SAW TRI TEST RING SYNC GATE CONTROL Write
13 ATK3 ATK2 ATK1 ATK0 DCY3 DCY2 DCY1 DCY0 ATK/DCY Write
14 STN3 STN2 STN1 STN0 RLS3 RLS2 RLS1 RLS0 STN/RLS Write
Filter:
15 - - - - - FC2 FC1 FC0 FC LO Write
16 FC10 FC9 FC8 FC7 FC6 FC5 FC4 FC3 FC HI Write
17 RES3 RES2 RES1 RES0 FILEX FILT3 FILT2 FILT1 RES/FILT Write
18 3 OFF HP BP LP VOL3 VOL2 VOL1 VOL0 MODE/VOL Write
Misc.:
19 PX7 PX6 PX5 PX4 PX3 PX2 PX1 PX0 POT X Read
1A PY7 PY6 PY5 PY4 PY3 PY2 PY1 PY0 POT Y Read
1B O7 O6 O5 O4 O3 O2 O1 O0 OSC3/RND Read
1C E7 E6 E5 E4 E3 E2 E1 E0 ENV3 Read
Table 2. SID Envelope Rates
VALUE ATTACK RATE DECAY/RELEASE RATE
Time/Cycle Time/Cycle
- ------------------------------------------
0 2 ms 6 ms
1 8 ms 24 ms
2 16 ms 48 ms
3 24 ms 72 ms
4 38 ms 114 ms
5 56 ms 168 ms
6 68 ms 204 ms
7 80 ms 240 ms
8 100 ms 300 ms
9 240 ms 750 ms
10 500 ms 1.5 s
11 800 ms 2.4 s
12 1 s 3 s
13 3 s 9 s
14 5 s 15 s
15 8 s 24 s
NOTE: Envelope rates are based on a 1.0 MHz ø2 clock. For other ø2 frequencies, multiply the given rate by 1 MHz/ø2. The rates refer to the amount of time per cycle. For example, given an ATTACK value of 2, the ATTACK cycle would take 16 ms to rise from zero to peak amplitude. The DECAY/RELEASE rates refer to the amount of time theses cycles would take to fall from peak amplitude to zero.
Picture 3. 6581 Envelope
/|\ - Reg 18: 0-3
/ | \ ^ Max. volume level
/ | \_____________ | - Reg 06,0D,14: 4-7
/ | | |\ | ^ Sustain level
/ | | | \ v v
-|---------|-----|------------|---|-- --- 0
| | | | |
|<------->|<--->| |<->|
| | Decay | Release
| Attack
Register description
Voice 1
FREQ LO/FREQ HI (Registers 00,01)
Together these registers form a 16-bit number which linearly
controls the frequency of oscillator 1. The frequency is
determined by the following equation:
Fout = (Fn * Fclk / 16777216) Hz
Where Fn is the 16-bit number in the frequency registers and
Fclk is the system clock applied to the ø2 input (pin 6).
For a standard PAL 0.985 MHz clock, the frequency is given by:
Fout = (Fn * 0.058725357) Hz
For a standard NTSC 1.023 MHz clock, the frequency is given by:
Fout = (Fn * 0.060959279) Hz
It should be noted that the frequency resolution of SID is
sufficient for any tuning scale and allows sweeping from note
to note (portamento) with no dicernable frequency steps.
PW LO/PW HI (Registers 02,03)
Together these registers form a 12-bit number (bits 4-7 of
PW HI are not used) which linearly controls the pulse width
(duty cycle) of the pulse waveform on Oscillator 1. The pulse
width is determined by the following equation:
PWout = (PWn/40.95) %
Where PWn is the 12-bit number in the Pulse Width registers.
The pulse width resolution allows the width to be smoothly
swept with no discernable stepping. Note that the pulse
waveform on Oscillator 1 must be selected in order for the
pulse width registers to have any audible effect. A value of 0
or 4095 ($FFF) in the pulse width registers will produce a
constant DC output, while a value of 2048 ($800) will produce a
square wave.
*********** FIXME: What is correct ***********
[A value of 4095 will not produce a constant DC output].
CONTROL REGISTER (Register 04)
This register contains eight control bits which select various
options on Oscillator 1.
+ GATE (Bit 0):
The GATE bit controls the envelope generator for voice 1.
When this bit is set to one, the envelope generator is gated
(triggered) and the ATTACK/DECAY/SUSTAIN cycle is initiated.
When the bit is reset to zero, the RELEASE cycle begins. The
envelope generator controls the amplitude of Oscillator 1
appearing at the audio output, therefore, the GATE bit must
be set (along with suitable envelope parameters) for the
selceted output of oscillator 1 to be audible.
+ SYNC (Bit 1):
The SYNC bit, when set to one, synchronizes the fundamental
frequency of oscillator 1 with the fundamental frequency of
oscillator 3, producing "Hard Sync" effects. Varying the
frequency of oscillator 1 with respect to oscillator 3
produces a wide range of complex harmonic structures from
voice 1 at the frequency of oscillator 3. In order for sync
to occur, oscillator 3 must be set to some frequency other
than zero but preferable lower than the frequency of
oscillator 1. No other parameters of voice 3 have any effect
on sync.
[NOTE: by Chuck Martin
For an explanation of SYNC, I'll use the sawtooth waveforms
as an example. The way the sawtooth waveform is produced is
by having a digital counter that begins at zero and counts up
by ones. When it reaches the maximum value (65535 in a 16 bit
DAC), it returns to zero and starts over. The way SYNC works
is that if both OSC 1 and OSC 3 are putting out a sawtooth
wave, but at two different frequencies, whenever OSC 3 resets
to zero, OSC 1 also resets to zero, even if it hasn't reached
its maximum value yet. If OSC 3 is set at a higher frequency
than OSC 1, OSC 1 gets reset prematurely, so both oscillators
end up running at the same frequency. OSC 1 will be at a
lower amplitude, however, since it never gets a chance to get
to its maximum value. This isn't very useful. If OSC 3 is set
at a lower frequency, however, you get an interesting effect
because if they start out at zero at the same time, OSC 1
will reach maximum first, reset to zero, and then start over.
When OSC 3 reaches maximum, it resets to zero and starts
over, but OSC 1 also resets to zero at the same time. The
result is that OSC 1 has alternating large and small teeth.
The lower OSC 3 is set, the larger the small tooth of OSC 1
becomes until OSC 3 reaches half the frequency of OSC 1 (one
octave lower), at which time OSC 1 again has all teeth the
same size. If you continue to lower the frequency of OSC 3,
OSC 1 will then have two large teeth followed by one small
tooth, and so on. Applying this same process to the pulse
wave produces alternating wide and narrow pulses. ]
+ RING MOD (Bit 2):
The RING MOD bit, when set to a one, replaces the triangle
waveform of output of oscillator 1 with a "Ring Modulated"
combination of oscillators 1 and 3. Varying the frequency of
oscillator 1 with respect to oscillator 3 produces a wide
range of non-harmonic overtone structures for creating bell
or gong sounds and for special effects. In order for ring
modulation to be audible, the triangle waveform of oscillator
1 must be selected and oscillator 3 must be set to some
frequency other than zero. No other parameters of voice 3
have any effect on ring modulation.
[NOTE: (by Chuck Martin)
A low cost form of ring modulation used in some analog
synthesizers was to run two square wave oscillators through a
digital exclusive or (XOR) gate. This is not true ring
modulation, but it has the same effect. The way the SID chip
most likely does this is to do a bitwise XOR on the digital
inputs of the DAC rather than on the square wave output
itself. It would do the same thing. Unlike the SYNC effect,
this will only work with square waves.
[NOTE: (by Lutz Sammer) This is how I have implemented the
RING MODULATION. ]]
+ TEST (Bit 3):
The TEST bit, when set to one, resets and locks oscillator 1
at zero until the TEST bit is cleared. The noise waveform
output of oscillator 1 is also reset and the pulse waveform
output is held at a DC level. Normally this bit is used for
testing purposes, however, it can be used to synchronize
oscillator 1 to external events, allowing the generation of
highly complex waveforms under real-time software control.
+ TRI (Bit 4):
When set to a one, the triangle waveform output of oscillator
1 is selected. The triangle waveform is low in harmonics and
has a mellow, flute-like quality.
+ SAW (Bit 5):
When set to one, the sawtooth waveform output of oscillator 1
is selected. The sawtooth waveform is rich in even and odd
harmonics and has a bright, brassy quality.
+ PULSE (Bit 6):
When set to one, the pulse waveform output of oscillator 1 is
selected. The harmonic content of this waveform can be
adjusted by the pulse width registers, producing tone
qualities ranging from a bright, hollow square wave to a
reedy pulse. Sweeping the pulse width in real-time produces a
dynamic "phasing" effect which adds a sense of motion to the
sound. Rapidly jumping between different pulse widths can
produce interesting harmonic sequences.
+ NOISE (bit 7):
When set to one, the noise output waveform of oscillator 1 is
selected. This output is a random signal which changes at the
frequency of oscillator 1. The sound quality can be varied
from a low rumbling to hissing white noise via the oscillator
frequency registers. Noise is useful in creating explosions,
gunshots, jet engines, wind, surf and other unpitched sounds,
as well as snare drums and cymbals. Sweeping the oscillator
frequency with noise selected produces a dramatic rushing
effect.
[The Noise output is not "true" random, as it is based on a
23 bit internal register].
One of the output waveforms must be selected for oscillator 1
to be audible, however it is NOT nescessary to de-select
waveforms to silence the output of voice 1. The amplitude of
voice 1 at the final output is a function of the envelope
generator only.
NOTE:
The oscillator output waveforms are NOT additive. If more than
one output waveform is selected simultaneously, the result will
be a logical ANDing of the waveforms.
[Transcriber's note: This is most probably wrong. Some claim
that it is the "min" function that is used, but my experience
is that it is more complex than that].
Although this technique can be used to generate additional
waveforms beyond the four listed above, it must be used with
care. If any other waveform is selected while noise is on, the
noise output can "lock up". If this occurs, the noise output
will remain silent until reset by the TEST bit or by bringing
RES (pin 5) low.
TODO
The following things should be done.
- Videosync under DOS should change the system clock!!
- Soundblaster 2 support for DOS.
- Cleanup of sources.
- Write more documentation.
- Use xresources for color configuration.
- Support the paddles and joystick under X11 with mouse.
- Variable autofire speed.
- Screen shot.
- Record of c64 sound.
- Snapshot of emulation.
- Left and right open borders.
- Rewrite sprite routines for more speed.
- DOS Overscan support needs rewrite for more speed.
- SVGALIB and DOS version needs support for blitter and linear frame buffer.
- Write own video mode for overscan, 400x300.
- Enhance 1541 emulation.
- GCR-write support for 1541 emulation.
- Automatic fastloader detection (What should be done, if detected?).
- Nice user interface (How multi platform?).
- Combine all sound drivers into one executable.
- More speed, more user friendly. (Suggestions)
Other informations
News groups
For information, questions and help you can look into following news
- groups
-
- comp.sys.cbm
- comp.emulators.cbm
- comp.emulators.misc
FAQs
This is the FAQ for _ALE C64_: alec64.faq
For more information read the following FAQs.
- comp.sys.cbm Commodore FTP sites list.
- comp.sys.cbm General FAQ.
- comp.emulators.cbm FAQ.
- comp.emulators.misc FAQ.
C64-ROM-IMAGES
Information to get original C64 ROM Images.
- ftp ftp.funet.fi
c64-basic.901226-01
Commodore 64 BASIC V2. The first and only revision.
c64-kernal.901227-01
Commodore 64 KERNAL ROM Revision 1. The RS-232 timing
table is designed for exactly 1 MHz system clock
frequency, although no C64 runs at that clock rate.
Ripped from a very old American C64.
c64-kernal.901227-02
Commodore 64 KERNAL ROM Revision 2. Can be found on 1982
and 1983 models.
c64-kernal.901227-03
Commodore 64 KERNAL ROM Revision 3. The last revision,
also used in the C128's C64 mode.
c64-kernal.sx
Commodore SX64/DX64 KERNAL. With different startup
colors, and tape routines disabled.
characters-c64
Commodore 64 character set. Every vertical line is at
least 2 pixels wide in order to avoid color errors on
television. Also the C=M and C=G graphic characters have
been made 2 pixels wide, which is an error.
1541-II.251968-03
1541-II C000-FFFF Roms.
* Please let me know if you know further sources.
Thanks to ...
Thanks to following people:
- Chuck Martin Helping me to implement ring-modulation and sync.
- Bernhard Maerz For the joystick support and testing.
- Christian Bauer He shows how easy it is to implement fast-loader support.
Thanks also to everyone else who has helped via sending suggestions, ideas, bug reports, questions and requests.
Bug reports
Send your bug reports, patches, improvements, questions and suggestions to johns98@gmx.net (Lutz Sammer) .
Copyright
The ALE C64 emulator:
Copyright (c) 1992-1996 by Andreas Arens, Lutz Sammer and Edgar
Törnig.
You can use and copy the binaries freely at no charge.
Contents
- Emulator Documentation
+ Description + Installation + Command line options + Environment + Keyboard + Joystick + CPU MOS 6510 + SID MOS 6581 or 8580 + VIC II MOS 6567 (NTSC) or 6569 (PAL) + Floppy Emulation + Extensions + Monitor + Utilities + Files + File Formats
- Original C64 Documentation
+ CPU MOS 6510 + SID MOS 6581 or 8580 + VIC II MOS 6567 (NTSC) or 6569 (PAL)
- TODO
- Other informations
- C64-ROM-IMAGES
- Thanks to ...
- Bug reports
- Copyright