Pfau Zeh for Linux Documentation

VIC 20 Emulator

Pfau Zeh for Linux

Documentation

Version 0.8 (24.11.97)

This documentation should help you to use the VIC 20 Emulator Pfau Zeh for Linux. You can read it with all available WWW Browsers. To display the included picture, you need a graphical browser like Netscape etc.

Pfau Zeh for Linux is :

a Commodore VIC 20 emulator for X86-ELF-Linux

Freeware, that means that you can use Pfau Zeh for Linux without paying any charge. You can give Pfau Zeh for Linux to others or put it on private CD-ROMs etc. when you don't modify this package. You must not modify anything of Pfau Zeh without my permission ! If you like to port Pfau Zeh to other platforms, feel free to contact me. If you want to publish it on any commercial CD-ROM, discs etc. you must contact me to get my permission.

PFAU ZEH FOR LINUX IS DISTRIBUTED "AS IS". NO WARRANTY OF ANY KIND IS EXPRESSED OR IMPLIED. YOU USE AT YOUR OWN RISK. THE AUTHOR WILL NOT BE LIABLE FOR DATA LOSS, DAMAGES, LOSS OF PROFITS OR ANY OTHER KIND OF LOSS WHILE USING OR MISUSING THIS SOFTWARE.

Arne Bockholdt

Table of contents :

What's new in version 0.8
Requirements to run Pfau Zeh for Linux
Installation
Command line options
Menu options
File format support
Video emulation
Sound emulation
Keyboard emulation
Joystick emulation
Paddle emulation
Light pen emulation
Comparison Pfau Zeh for Linux => VIC 20
To do...
Compatibility
Questions and answers
Reporting bugs, problems, comments and mailing list
New releases and Pfau Zeh for Linux home page
History
Thanks to...

What's new in version 0.8 :

New window sizes should be more like the original screen format
Better menu handling
Bug fixes
other minor changes

Requirements to run Pfau Zeh for Linux

Hardware :

a X86-compatible personal computer with at least a speedy 80486 processor. A "Fifth generation" processor (or better) is recommended.
an accelerated local-bus graphic card
optional : a sound card with the capability to produce a 8 Bit 44.1 khz mono output
optional : a PC-joystick

Software :

Linux for X86-compatible computers
X11R6 (or later) with MIT-Shared memory extension
C-Library Libc 5.4.XX
an accelerated X-Server (like Xfree86 or Accel-X) with 8 bit color depth
both kernel sets of the original VIC 20
optional : Kernel with Linux sound driver
optional : Linux joystick module
optional : Tons of old games to have the real (nostalgic) VIC 20 feeling

Installation

First of all, please extract the Pfau Zeh for Linux package with

tar -xzf pfauzehv08.tar.gz

. It will create a directory structure like this :

PfauZehv0.8/
- roms/
- docs/
- games/

In the ROMS/ directors there're the following ROM files: :

kernel.pal
PAL Kernel ROM, 8 KB
kernel.ntsc
NTSC Kernel ROM, 8 KB
chargen.rom
Character generator ROM, 4 KB
basic.rom
Basic interpreter ROM, 8 KB

You can find these ROM sets on this FTP Server :

ftp.funet.fi/pub/cbm/firmware/vic20

The ROMs are copyrighted by Commodore Business Machines.

That's all ! Please compile your Linux kernel with sound driver enabled to get sound output and install the Linux joystick module to control the VIC 20 games with a real joystick.

Command line options

Pfau Zeh for Linux got the following command line options :

-h
Displays a help text with command line parameters and keys

-ram
$a000-$bfff will be RAM instead of ROM (default : $a000-$bfff is ROM)
-nocfg
Using defaults instead of settings in configuration file
-nosound
Disables sound emulation (default : Sound emulation is enabled)
-tvsound
Enables television sound emulation (default : TV emulation is disabled)
-joy
Enables joystick emulation with /dev/js0 (default : joystick emulation with key control)

-highres
Enables the scaling option for the Pfau Zeh for Linux window. You need a screen resolution >= 800x600 and a very fast computer.

-verbose
When you use this command line parameter all startup messages will be displayed. Only necessary if the startup of Pfau Zeh for Linux fails.
game.crt
load CRT file to address $a000 (8 kb file) and $6000 (16 kb file)

game.x0
load game to address $x000
game.prg
loads game to address in file header (default : $a000)

You can specify more than one image at the command line. All images will be loaded into VIC memory.

Menu options

The Pfau Zeh for Linux menus gives you the possibility to control Pfau Zeh for Linux in various ways. Here is a short description of the menus and their functions :

File menu :

Load/Save Basic :
This is the only way to load or save your BASIC programs. You must enter the name of the file or choose the file in the file selector dialog. The file will be checked for the right memory expansion for this program. If you got the wrong memory expansion inserted you must reset the VIC and load the program again. Now you can type "RUN" to start the program ;-)

To load a BASIC program you must wait till the VIC has finished his "POST" and the VIC starting screen has been displayed !

Default :
- none
Hot Keys :
- F2 (load BASIC program)
- F4 (save BASIC program)

Load Cart :
This is the second way to insert a cartridge into the VIC 20. It uses the same code to find out the starting address like the command line. To start a cartridge with auto-start sequence please reset the VIC !

Default :
- none
Hot Keys :
- none
Remove Cartridge(s) :
When you want to start another cart or if you want to enter a BASIC program, you must remove the inserted cartridges. You can manage this with this option. All inserted carts will be removed and the VIC 20 will be resetted.

Default :
- none
Hot Keys :
- none

Save config :
Pfau Zeh for Linux uses a configuration file for your settings called "pfauzeh.rc". If you choose this option your current settings will be saved to this file and will be taken from this file with every start of Pfau Zeh for Linux. Use "-nocfg" to override this.

Default :
- none
Hot Keys :
- none
Exit Pfau Zeh for Linux :
If you want to turn of the VIC 20, please turn this switch off.

Default :
- none
Hot Keys :
- ESC

Options menu :

Memory ... :

Memory expansion :
This is the amount of expansion memory you want to give your VIC 20. Some programs need a special amount of memory. Unexpanded means the standard 3.5 kb RAM.
The emulator will be resetted when you change this setting.

Default :
- Unexpanded
Hot keys :
- none
RAM at $a000 :
This is the same setting as the command line parameter "-ram". With this setting you can declare the $a000-$bfff VIC 20 memory locations as RAM instead of ROM. At least one game (Amidar) needs this because its cartridge seems to have RAM memory.

Default :
- $a000-$bfff is ROM (disabled, box isn't checked)
Hot Key :
- none

Speed ... :

Frame rate sizes :
This setting tells Pfau Zeh for Linux how often it should render a new frame. A real VIC 20 displays 50 frames per second (PAL) or 60 fps (NTSC). This is the setting 1/1. Rendering frames costs very much CPU power, so you should lower the rate if you find that the VIC 20 runs to slow. There should be no visible difference with 1/2 frame rate compared with 1/1 but it needs nearly half the CPU-time !

Default :
- 1/2
Hot keys :
- none
Delay :
This is a delay value. For fast computers (>166 MHz) it is necessary to slow down Pfau Zeh for Linux. The higher this value is, the slower the emulation is. Please set the frame rate to 1/1 first, instead of delaying the emulation.

Default :
- 0 cycles
Hot Key :
- none

Video ... :

Video timing :
This is a very important setting to run some programs successfully. Please refer to the video emulation section for further details. The emulator will reset when you change this setting.

Default :
- NTSC-M (6560)
Hot Key :
- none
Overscan :
You can choose how much VIC 20 lines the video emulation don't display at the top of the screen. Some programs need this setting set to 9 lines to see the whole screen. The emulator will reset when you change this setting.

Default :
- 28 lines
Hot Key :
- none

Reset VIC 20... :

Reset the VIC 20 :
To apply some settings, start a cartridge or to start over with the VIC you must reset the VIC. It's a cold start, all data in the VIC memory gets lost (except carts in $a000-$bfff)

Default :
- none
Hot Keys :
- F11

File format support

Here's a list of supported file formats :

CRT format :
Type :
- Cartridge ROM
Size :
- 4, 8 or 16 KB
Address :
- 8 kb to $a000
  16 kb to $a000 (8 kb) and $6000 (8 kb)
  Address from header if present, you can identify a file with header if the size of this file is X*4096+2 (X=1,2,4). Header Size : 2 Bytes
How to load :
- Command line
  load cart in File menu
X0 format (X0 is normally A0, B0, 20 or 60):
Type :
- Cartridge ROM
Size :
- 4, 8 KB
Address :
- $X000
How to load :
- Command line
  load cart in File menu
PRG format (1st possibility):
Type :
- Cartridge ROM
Size :
- 4, 8 KB
Address :
- address from header of file
How to load :
- Command line
  load cart in File menu
PRG format (2nd possibility):
Type :
- BASIC program
Size :
- Various
Address :
- address from header of file
How to load :
- load BASIC in File menu
unknown suffix (1st possibility):
Type :
- Cartridge ROM
Size :
- 4, 8 kb
Address :
- $a000
How to load :
- Command line
  load cart in File menu
unknown suffix (2nd possibility):
Type :
- BASIC program
Size :
- Various
Address :
- address from header of file (BASIC)
How to load :
- load BASIC in File menu

Not supported are :

S20 file format ( will come with next version)
PC-VIC snap shot format PCV
V20 snap shot format V20 (I miss some important things in this snap shot format)
any kind of tape and disc formats
multipart basic programs

Video emulation

There are two different video modes for two different TV systems. The german VC 20 used the PAL system and the american VIC 20 used the NTSC system.

You can choose the emulated video system with the Video timing option in the Option/Video menu. Some games needs the PAL timing, others the NTSC timing. Here's a small table with a comparison between this two timings.

Timing :	PAL	NTSC
Lines per frame :	312	261
Frame rate :	50	60
Screen width :	233	210
Screen height :	284(9 lines), 265 (28 lines)	233 (9 lines), 214 (28 lines)

The position of the output screen in the window depends from the video timing and the sound is different too. If the position of the frame in the window isn't correct with your program, try the other video mode!
The kernel ROM file will be reloaded when you change the video timing !

You can double the height and the width of the Pfau Zeh window with the "-highres" parameter but it needs 4 times the CPU time to display one frame. You need a very fast computer to use this option...

Sound emulation

The VIC 20 produces 3 melodic and 1 noise voice. There's a volume control for this voices too. Pfau Zeh for Linux emulates all of this sound features with help of the DSP on your sound card. This sounds much better compared with FM synthesis or something like that but it costs much more CPU time to produce this samples.

Pfau Zeh for Linux renders 8 Bit mono samples with 44.1 khz sampling rate.

If you want to hear this sounds you must have a sound card with Linux driver in the Linux kernel. All PC sound cards should be able to play this kind of samples.
If you don't have a sound card you can disable the sound output with the

-nosound

command line parameter, but Pfau Zeh for Linux tests the presence of a sound card each time it starts, so there should be no need for this option...

If you want to get a more realistic sound output use the

-tvsound

command line parameter. You will get a smoother sound with some noise like on a real VIC 20 with an old TV. Please mail me your comments about this "feature" !!!!
The TV sound emulation needs much more CPU time as the normal sound emulation because it renders two more voices and uses another wave form for the melodic voices.

Keyboard emulation

The VIC 20 has got a nice keyboard very similar to a PC keyboard. Here's a picture of the VIC 20.
Keyboard Layout

On this picture you see the differences between the VIC keyboard and the keys Pfau Zeh for Linux uses for the emulation. Here's a list :

RUN-STOP = TAB key

Control = Left Control key

CBM = Left ALT key

Home = Home (Pos 1) Key

£ = Insert Key

Cursor Down = Page Down Key

Cursor Right = Page Up Key

Arrow Up = End Key

Restore = F12

Remember : The keys F2, F4, F6 and F8 are accessed by pressing F1, F3, F5 and F7 with one of the shift keys !!!!

Pfau Zeh for Linux is developed for US-layout keyboards, so if you use another one (e.g. german ;-) ) you can't use all keys.

Joystick emulation

You can emulate the VIC 20 Joystick in two different ways :

Connect a real joystick to your game port, install the Linux joystick module and start Pfau Zeh for Linux with the

-joy

option. You must center the joystick when you start the emulator because Pfau Zeh for Linux tries to calibrate it for its use. This option disables the keyboard joystick emulation !

Simulate the joystick with some keys on your keyboard. This is default. The keys for the joystick are :
Fire :

Right control key

Directions :

Cursor keys or Cursor keys on Numblock with Numlock enabled

Paddles emulation

Pfau Zeh for Linux got a simple paddles emulation. Some games needs this controller type. Use the following keys for the paddles :

Paddle 1
Left : Numblock end (1)

Right : Numblock page down (3)

Fire : Cursor key left
Paddle 2
Left : Numblock pos1 (7)

Right : Numblock page up ( 9)

Fire : Cursor key right

To use the directions of the paddles you need to numlock the number block ! The fire keys are the same as the left/right directions of the keyboard joystick emulation.

Light Pen emulation

The Light pen emulation is implemented with help of the mouse. You can choose the desired position on the Pfau Zeh for Linux screen with the mouse cursor and press any button of the mouse.

Light Pen :
Position : Mouse

Fire : any mouse button

There aren't many programs for the VIC 20 that use a light pen. The only one I know is "Commodore Artist". It seems to work well in NTSC mode. If you find other programs with light pen control, please send them to me !!!!!!

Comparison Pfau Zeh for Linux => VIC 20

This section should inform you about the "quality" of Pfau Zeh for Linux. It tells you which parts of a real VIC 20 are emulated from Pfau Zeh for Linux.

Emulated :
6502 :

Legal opcodes

Illegal opcodes

Timings

Interrupt, NMI

should be 100 % !

VIA 1:

Ports A/B

DDRs

ACR

PCR

IRQ

Timer 1/2 incl. latches

Joystick

Restore key

VIA 2

Ports A/B

DDRs

PCR

ACR

IRQ

Timer 1/2 incl. latches

Keyboard

Joystick

VIC

All graphic modes

16 Colors

Screen origin registers

TV raster beam

Paddles

Light pen

Sound (3 melodic + 1 noise + volume)

Inverted mode

etc.

Misc.

memory expansions

PAL/NTSC version of VIC 20

VIC 20 Keyboard

Joystick

Light Pen

Paddles

Reset button

etc

Not emulated :

VIA 1

Shift register

Parts of RS 232 / User Port

Parts of Tape control

VIA 2

Shift register

Parts of serial interface

Parts of Tape control

VIC

Interlaced mode (NTSC only)

NTSC first line at the bottom of the screen

Misc.

Tape emulation

Disc emulation

To do...

Here's the list of things that I plan to implement / enhance / change in Pfau Zeh for Linux for the future :

6502

speed up code

VIC
- a better graphic emulation, at the moment a whole line is drawn, a pixel-based emulation would do better...
- correct NTSC emulation (first line)
VIA 1
- tape
- shift register emulation, but no program use it (except serial transfers)
- RS-232 (see above)
VIA 2
- tape
- shift register (see above)
- serial bus (disc drive, printer)
I/O
- tape
- disc
- printer
Misc.
- Port Pfau Zeh for Linux to other OSs
- snapshots of the VIC 20 memory and registers on disc e.g. PCV file format
- fixing some bugs (a never-ending story...)
- a debugger window
- using better color model, with the used global color model the colors are different depending on the colors used by other programs.
- possibility to run Pfau Zeh for Linux with other X-Server color depths (16, 24 bit)
- synchronize Pfau Zeh for Linux with the speed of host computer. My documentation about the Linux syscalls is very rare.
- better paddles emulation
- suggestions are always welcomed

Compatibility

Here're the programs I've tested with the current version of Pfau Zeh for Linux and the results I get. If you've got corrections or additions, please mail them to me. Thank you !

These programs should work fine with Pfau Zeh for Linux :

Name of tested program :	Comment :
AE
Aggressor
Alien Blitz
Alien Side-Step
Amidar	use -ram parameter and PAL timing
Andes Attack
Andromeda
Ape Escape
Apple Panic
Arachnoid
Arrow of Death
Artillery Duel
Astro Blitz
Astro Panic
Atlantis	needs NTSC timing
Attack of the mutant camels
Avenger
Bandits	needs NTSC timing
Battle Zone
Bewitched	ROM version needs SYS 40985
Black Hole
Buck Rogers	needs NTSC timing
Bumper Bash
Car Race
Catch a Snatch
Caterpilla
Cave in
Centipede
Chariot Race
Choplifter
Chuck Norris Superkicks
Cloudburst	needs PAL timing
Clowns
Commodore Artist	needs NTSC timing
Computer War
Congo Bongo
Cosmic Cruncher
Cosmic Firebirds
Cosmic Jailbreak
Crawler
Creepy Corridors
Crossfire
Dancing Bear
Dark Dungeons
Deadly Duck
Defender
Dig Dug
Donkey Kong
Doolhof
ET	needs SYS 43762 from BASIC
Face Maker
Fast Eddie
Final Orbit	needs NTSC timing
Flightpath 737
Football Manager
Forth Encounter
Fort Knox
Frogger
Galactic Abductors
Galaxian
Garden Wars
Ghost Manors	needs NTSC timing
Gold Fever
Gorf
Grandmaster
Gridder
Gridrunner
Guardian
Hellgate
Hesmon
Heswriter
Home Babysitter
ICBM
In the Chips
Jawbreaker
Jawbreaker II
Jelly Monster	use the "fixed" version from ftp.funet.fi
JetPac
Jungle Hunt
Jupiter Defender
Kids on Keys
K-Razy Antiks
Loderunner
Lunar Leeper
Mad Boogie
Mastertype
Matrix
Menagerie
Meteors
Mets
Miner 2049'er
Mole Attack
Money Wars	needs NTSC timing
Monster Maze
Moon Patrol
Moons of Jupiter
Mosquito Infestation	needs PAL timing
Mountain King
Ms. Pac Man
Munchman
Music Composer
Mutant Herd
Number Nabber Shape Grabber
Omega Race
Orbis
Outworld
Pac Man
Paratrooper
Perils of Willy
Personal Finance
Pharaohs Curse
Pinball
Pipes
Poker
Polaris
Pole Position	needs NTSC timing
Predator
Princess and Frog	needs NTSC timing
Programmers Aid	Start Pfau Zeh for Linux, choose 24 KB memory expansion, reset VIC, load cart, don't reset !, type SYS 28681
Protector
Q-Bert
Quackers	needs PAL timing
Radar Rat Race
Rat Hotel
Renaissance
River Rescue	my first game on a VIC !
Road Race
Robin Hood
Robotron
Sargon II
Satellite Patrol
Satellites and Meteorites
Scorpion
Sea Wolve
Seeschlacht
Serpentine
Sir Lancelot
Skibberen
Skramble	seems to use illegal opcodes !
Sky Blazer
Snake Byte
Speed Math
Spiders of Mars
Spike's Peak	needs NTSC timing
Star Battle
Star Patrol
Star Post	needs NTSC timing
Star Trek
Sub Chase
Super Amok
Synthsong
Synthsound
Tank Atak
Terraguard	needs PAL timing
Threshold
Thriller	needs PAL timing
Titan
Tomarc the Barbarian
Tooth Invaders	needs PAL timing
Topper	needs NTSC timing
Tower of Evil
Trashman
Traxx	needs PAL timing
Tron
Turmoil	needs NTSC timing
Type Attack
VIC Blitz
VIC Boogie
VIC Chess
VIC Color Test	Load BASIC, reset VIC
VIC Graph
VIC Super Lander
VIC Super Slot
Video Man
Video Vermin
Wacky Waiters
Wordcraft	needs >= 8 kb memory expansion
World at War
Xeno II	needs PAL timing

These programs have some problems with Pfau Zeh for Linux :

Arcadia	needs PAL timing, game timer seems too fast
Bongo	needs PAL timing, problems with keyboard emulation
Demon Attack	needs PAL timing, minor graphic problems
Dragonfire	needs PAL timing, minor graphic problems
Krell	problems with keyboard emulation, use joystick instead
Meteor Run	Seems to work correct, I don't know the original
Robot Panic	seems to have some timing problems ???
Star Defence	needs PAL timing, start screen is invisible, press fire button to start

These programs don't work with Pfau Zeh for Linux :

Cannonball Blitz	program jumps into empty RAM, maybe a corrupted image file
Plasma from VVV (PAL timing)	Pfau Zeh for Linux got serious problems with this but NTSC version seems to work

Questions and answers :

Question :	Answer :
The screen position of a program isn't right. What is wrong ?	Perhaps you use the wrong video timing for this program. Please change this setting in the Video menu.
I can't run Pfau Zeh for Linux and I get only a message "failed" at startup. Why ?	Use the "-verbose" parameter to see why Pfau Zeh for Linux fails to start.
Program XXXX seems not to work correctly with Pfau Zeh. What can I do ?	Have a look at the compatibility list in this file for a comment to this game. Change the video timing. If this doesn't help, please send me the game for testing
Pfau Zeh for Linux fails when it tried to allocate colors. Why?	You run another program which uses much colors. Please close it first and try again.
Pfau Zeh for Linux is too fast. What can I do ?	Set the frame rate to a higher value or/and increase the slow down delay. Use a higher resolution with "-highres" parameter
Pfau Zeh for Linux is too slow. What can I do ?	Set the frame rate to a lower value and set the slow down delay to 0. Use the normal resolution. You can disable the sound with -nosound parameter or the -tvsound option. You should use the key joystick control because it's faster than the /dev/js0 joystick emulation. And last but not least buy a faster computer ;-)
Where can I find the joystick driver for Linux ?	Try this URL : sunsite.unc.edu I think the latest version is 0.8.0. There's a patch for kernel versions 2.1.X too.
Will there be ports of Pfau Zeh for Linux for other OS ?	A Win32 port is available. It runs with Win95/98 or WinNT. Perhaps there will be other ports, too. If you want to port it to other operating systems feel free to contact me !
Where can I find games or tools ?	Download them from : ftp.funet.fi/pub/cbm/vic20/
What the hell does Pfau Zeh for Linux means ?	Well, a good question. At the very beginning it was a joke name for my project. The german VIC 20 was called VC 20, I think the reason for that name was the similarity to VW (Volkswagen, a german car manufacturer), the VC 20 should be the VolksComputer, a computer for everybody (like the Volkswagen, a car for everybody). You pronounce the "V" in german like "Pfau" and the "C" like "Zeh". Pfau Zeh simply means "VC" like the german name for the VIC !

Reporting bugs, problems, comments and mailing list:

If you got problems to run Pfau Zeh for Linux or if you find any bugs in it, please contact me and send me a mail to my address :

pfauzeh@classicgaming.com

Any kind of comments are welcome, too. If you find a program which doesn't work with Pfau Zeh for Linux or got any glitches, please send it to me. Thank you in advance !

There's also a mailing list where I announce new version of Pfau Zeh for Linux. Please send me an email and I will put you on the list.

New releases and Pfau Zeh for Linux home page:

You can find new releases on the Pfau Zeh for Linux home page at :

http://www.classicgaming.com/pfauzeh

If you want to be notified if a new version has been released I can put you on the Pfau Zeh for Linux Mailing list. For further information see above.

History :

Pfau Zeh is a project I started at the 1st. October 1996. It's the first emulator project I've made and the first program for X-Windows, too

The Commodore VC 20 (the german version of the VIC) was the first home computer I've seen in my life. I've played "River Rescue" on the VIC of a good friend. That's one of the main reasons for me to develop this emulator. And I'm very happy to see that River Rescue runs on Pfau Zeh, it's a very nostalgic feeling, my first computer game ever...
In the past Pfau Zeh was called Pfau Zeh (ASP) but this is obsolete now...

Well, here's the changes since version 0.1beta :

V0.8, build date 24.11.97

changed window sizes (streched x2 in x-direction)
changed menu handling. Changed settings will be applied instantly
video memory is now 4 bit instead of 8 bit
fixed problems with screen positions registers
fixed bug in reset code (e.g. MS. Pac Man)
renamed Pfau Zeh to Pfau Zeh for Linux
other minor changes
ROMs are included now !

V0.7, build date 29.07.97

new Motif-based GUI. No Control Panel anymore...
added scaling option for Pfau Zeh window. Use the command line parameter "-highres" to double the height and the width of the window
added memory initialization. Some games need this (e.g. Poker, AE and Miner 2049'er)
new window sizes in both video modes according to new VIC-I documentation from Marko.
"Overscan" option in Video menu to switch between the old (28 lines) and the new (9 lines) screen size.
added "Remove Cartridges" option in File menu to clear the Cartridge ROM memory.
fixed the bug in illegal ARR opcode (decimal mode). 6502 emulation should be 100 % now !!
startup messages will be only displayed when you use the command line parameter "-verbose"
rewritten mouse and keyboard event handler.
fixed some bugs in sound emulation.
fixed a bug in PRG loading code
other minor bug fixes

V0.6, build date 07.07.97

added joystick emulation for joystick /dev/js0. Please install the joystick module to use the joystick.
added light pen emulation. Use the mouse with any button.
added support for CRT files with loading address in header
changed cursors of Main and Input windows
sound process will be killed if start of Pfau Zeh failed
rewritten documentation and converted it to HTML format.

V0.55, build date 28.05.97

added rest of illegal opcodes and test all with the C64 test suite from Wolfgang Lorenz. ARR seems to have a bug in decimal mode.
changed screen height. It is one scan line smaller now. (intro from VVV, thanks Marko !)
added TV Sound option. You will get a more realistic emulation of the VIC 20 sound over a (bad) television. Use "-tvsound" to get this feeling !
allow loading of (BASIC) programs to all addresses
added support for new VIC 20 Programs on ftp.funet.fi (PRG format) with two bytes header
added the possibility to enter space key in File Input window
fixed a small bug in new VIA timer 1 code (Demon Attack)

V0.5, build date 12.04.97

changed the window sizes once again (the last time ?). Now only the part of the screen is visible which is visible on a real VIC 20. Some demos needs this e.g. intro from Veni Vidi Vic !
tested a modified version of Pfau Zeh ("Zeh 64") with some C64 6510 test suites. Fixed some bugs in SBC opcodes and flag handling. 6502 Emulation should be 100% now. (hopefully...)
added inverted video mode (e.g. Dragonfire, Demon Attack, Intro from VVV)
added reloading of kernel when video timing has been changed. You *need* both ROM sets ==> rename NTSC kernel to "kernel.ntsc" and PAL kernel to "kernel.pal".
fixed a bug in VIA 2 joystick/keyboard code (Jetpac)
timing of VIA timer 1 is perfect now (River Rescue, Final Orbit, Bandits)
changed VIA timer 1 "one-shot" mode emulation
changed initial value of paddles registers
fixed a small bug in "-" key emulation
added limits for video columns and rows in NTSC mode
added some illegal opcodes (Skramble)

V0.41 release, build date 24.3.97

re-added initial value for VIA ACR registers (timer 1), Thriller need this for the smiling skulls.

V0.4 release, build date 24.3.97

6502 :

fixed a bug in READMEM code, it will return the page number in non-existing memory instead of a 0.
better opcodes timings
better NMI/Interrupt timing (River Rescue)
fixed a bug in JMP (indirect) opcode
fixed a bug in indirect indexed addressing mode opcodes

VIA :

Via 1+2 timer 2 will start timing at power-on too
changed defaults for VIA 1 timer 1 latches
rewritten NMI/Interrupt/VIA IFR code, should be more accurate now (Scorpion)
added some other positions of the VIA registers in memory.
fixed a bug in VIA timer 1 code for PB7 output
fixed a small bug in VIA 1 timer 1 "one-shot mode" code
fixed a bug in VIA IER code
added initial value for VIA shift registers

VIC :

added automatic window resizing of main window in dependence of the video timing. NTSC timing mode has now a smaller window. (Starpost) ==> please use the right ROMS (NTSC, PAL) to get a proper screen position
fixed a bug with scan line counter registers in NTSC mode (Final Orbit, Ghost Manor, Spike's Peak, Bandits etc.)
minor changes in sound emulation
optimized graphic emulation code => should be a bit faster now

Misc. :

added slow down option to Control Panel for fast computer. Removed 1/7 to 1/10 frame rate options.
fixed some bugs in reset code
fixed a bug (?) in window code (caused sometimes a XLib error)
added support for 8193 bytes CRT files (ssmash.crt)
changed input window title and cart loading code in Control Panel
fixed a bug in memory expansion size option in Control Panel
found many bugs in Data Becker's "VC 20 intern" (2. Edition) ;-)

V0.4 beta1, build date 15.3.97

rewritten VIA Output/Input/Data Direction Register code => better keyboard, joystick etc. emulation (Type Attack, Snake Byte, Robin Hood)
rewritten VIA timer 2 code
added some workarounds for missing disc/tape/RS 232 emulation (e.g. unex) => you will get a "device not present error" instead of an emulator crash
VIA 1 timer 1 will start timing at power-on too
added auto selection of memory expansion size for basic programs
added restoring of window while entering filenames
added numblock cursor keys as joystick emulation (NUMLOCK !)
fixed a bug in some opcodes (ROL abs, LSR abs etc.

V0.3 release, build date 9.3.97

added file loading/saving options to the Control Panel
adjusted some colors, should be more accurate now
added auto detection of sound card
main window gets the focus at startup (at last !)
added saving of video timing to configuration file
added "-nocfg" parameter to use the default settings
added "-nosound" parameter to turn sound emulation off
removed "-PAL" parameter
new compiler gcc 2.7.2 -> 2.7.2.1, libs etc.
minor other changes

V0.3 beta2, build date 10.2.97

added sound emulation (3 melodic + 1 noise channel + volume control)
added "quick'n'dirty" Pfau Zeh Control Panel. It is VIC 20 like, isn't it ?
fixed a bug in optimized 6502 code
changed Basic saving code. When you try to save a program without having one in memory, nothing will be written now
major internal changes for faster developing
removed auto saving function. Please use the Control Panel to save the configuration
added game Thriller with permission of Bernd Wiebelt

V0.3 beta1, build date 2.2.97

rewritten graphics emulation. Now real scantiness are emulated. There should be less flickering and nice raster effects, but the emulation is slower. The raster counter emulation is accurate now, the timing should be better with some games. (try Pole Position :-)))))))))).
changed border emulation. Now raster effects are supported. This is the main reason for the slowdown of the emulation.
changed speed control. With F2 and F4 you can control the frame rate. Default is 1/2 (every second frame is drawn)
added "-PAL" option. You can change the video timing with this parameter. Some games need this video timing. PAL timing is slightly slower. Default is NTSC.
changed event handler code (slightly faster)
optimized 6502 code (slightly faster)

V0.2 release, build date 30.1.97

fixed bug in NMI code (e.g. Dig Dug, Deadly Duck)
fixed another Via 1 Timer 1 bug (Thriller, Gorf)
fixed a bug in opcodes with zero-page indexed addressing mode which caused wrong results in floating point arithmetic (it was another bug of my 6502 documentation, I should buy another book)
added saving basic program function (F10)
added support for cartridge files with two bytes header
changed the cartridge loading code

V0.2 beta2, build date 22.1.97

changed interrupt and timer check method, timers and interrupts will be checked after each instruction => timing is better, but emulation might be slower
fixed Via IFR bug (e.g. Atlantis, Donkey Kong, Moon Patrol)
more accurate raster counter emulation
changed configuration file saving
fixed a bug with memory expansions and cart games
fixed a small screen resizing bug (Jungle Hunt)
added support for (basic) PRG files with loading address $a000
added "-ram" parameter, see README for details (Amidar)
added emulation of VIC screen origin registers (e.g. Thriller, Jungle Hunt)
optimized 6502 memory access

V0.2 beta1, build date 12.1.97

fixed major VIA timer 1 bug (e.g. keyboard repeat, nearly all games....)
fixed silly bug in Compare opcodes
fixed bug in screen height calculation (Robot Panic)
changed window size again
added second VIC 20 keyboard scan method emulation (e.g. Battle Zone, Donkey Kong, Pole Position), hard work to find this...
changed raster counter emulation (problems with AE and Sub Chase)
fixed basic program loading bug
added Restore key emulation (F12)
added support for .CRT images
fixed other minor bugs
more optimizations
added list of tested games

V0.1 release, build date 8.1.97

implemented MIT-shared memory support, the display and the whole emulator is much faster now :-)))
added rest of keyboard emulation (keysyms) except Restore key
optimized screen draw method
a few other optimizations
fixed some minor bugs (Starpost should run now but buggy)
minor internal changes

V0.1 beta4, build date 16.12.96

fixed offscreen buffer bug (e.g. Thriller, Buck Rogers, Star Patrol). It caused many illegal opcodes...
changed window size

V0.1 beta3, build date 13.12.96

complete new keyboard and joystick emulation code (VIA Data Direction Registers bug fixed)
added emulation of all memory expansions (F6 and F8)
added support for all basic tapes
added loading of ROMs to addresses $b000, $2000
added reset function (F11)
changed cart loading code, auto detection of address to load (file suffix)
fixed bugs in character address calculation
changed window properties
changed border draw code (less flicker)
fixed RUN-STOP bug
fixed other minor bugs

V0.1 beta2, Build date 27.11.96

No need for a setup program anymore. Speed can be changed within the emulation by pressing F2 and F4 now. Changes will be saved.
Loading of Basic tapes by pressing F9 (8k+ only for now)
added documentation

Thanks to...

I would like to thank for their help on this project :

Lance Ewing (be@ihug.co.nz)
Author of the VIC 20 emulator V20 for DOS for lots of help and for his great documentation.

Marko Mäkelä (Marko.Makela@HUT.FI)
For his very accurate VIA/VIC/6502 documentation, some suggestions to improve Pfau Zeh and for bug reporting.

Bernd Wiebelt (bernado@studi.mathematik.hu-berlin.de)
Author of Thriller for his permission to include Thriller in the Pfau Zeh package and for his beta testing

Marat Fayzullin (fms@freeflight.com)
Author of many emulators, in my case I must thank him for his DASM (6502 disassembler) program. It helps me debugging my emulator.
Wolfgang Lorenz
For his nice 6510 test suite. I've tested my 6502 emulation with it. Unfortunately he stopped the developing of his PC64 emulator...
Sarah Dalrymple ... (saz@jdal.demon.co.uk)
I've taken the VIC 20 picture from her VIC 20 Page. URL : The World of JAZ
all other beta testers for sending me bug reports.

Have a lot of nostalgic feelings !