Revision history

"Those days, the Third Age of Middle-earth,
are now long past, and the shape of all lands
has been changed."

This emulator started as a player routine for C64 music on the Amiga. Versions V1.x were written in 68K assembly language, versions V2.x in a mix of 68K assembly and C. V3.x/V4.x are portable versions written in C++.

V1.x/V2.x

Amiga 68K versions

V3.0

First release of BeOS/Unix version, features processor-level 1541 emulation and built-in SID emulation

V3.0a

Implemented SID test bits
Combined SID waveforms respect pulse width
Corrected idle state graphics display
Processor-level 1541 emulation respects .d64 error info
CPU emulation optimized (6510 and 6502 split)
VIC emulation optimized (raster counter in local variable in EmulateLine())
BeOS: Now exiting the audio subscriber with ExitStream(TRUE)
Unix: Fixed missing thread_func() declaration
Unix: getcwd(AppDirPath) was missing in main_x.i
Unix: Speed limiter works

V3.0b

Implemented REU emulation
Formatting disks with ID possible under processor-level 1541 emulation
Corrected and optimized SID waveform/envelope calculation (signed arithmetic)
Corrected idle state display again (ECM text)
1541 D64 mode ignores drive numbers when opening the directory
Processor-level 1541 emulation deactivates when idle
BeOS: Sound output quality is now 16 bits
Unix: Quits more cleanly, reactivates key repeat
Unix: Fixed alignment problem with text_chunky_buf in VIC.h

V3.0c

1541 DIR mode can load directory with "$0"
Rearranged the CPU code (more macros, less inline functions)
SID envelope generators rewritten, envelopes are now recalculated for every sample
SID calc_buffer function now takes pointer to WORD buffer
Unix: Sound for Linux
Unix: Prefs window implemented (needs Tcl/Tk)
Unix: Corrected x64 disk image detection on little-endian systems
Unix: SVGAlib support works again, accesses frame buffer directly if possible
Unix: Added support for SHM under X11

V3.0d

SID filter emulation implemented
SID master volume setting works again
Flags are recalculated in MOS6526::SetState()
Changed CBOOL->bool in some places
Fixed bug with char_in in MOS6510::new_config()
BeOS: Emulation thread priority lowered
Unix: Some changes for DEC Alpha
Unix: Joystick support for Linux

V3.0e

Removed the CBOOL data type
Unix: Sound for HP-UX
Unix: Keyboard layout matches the picture in the docs more closely
Unix: Diagonal directions of keypad joystick emulation work
Unix: +/- on numerical keypad modifies SkipFrames
Unix: F9 invokes SAM
Unix: Drive LEDs and speedometer implemented
Unix: Some changes to the GUI
Unix: Random number generator is initialized
Unix: Name of prefs file can be given as an argument
Unix: Calls XFlush() and XSync() in C64Display::Update()

V3.0f

Improved DIR/D64 drive reset, resetting the C64 resets the drives
Implemented 'G' command for DIR/D64 drives
Corrected translation of 0xc1..0xda characters in conv_from_64()
BeOS: Implemented smart "Insert next disk" menu item
Unix: Improved the speedometer/LED bar
Unix: Self-calibrating joystick routines
Unix: No need to enter path of 'wish' in TkGui.tcl

V3.0g

New T64/LYNX mode for 1541 emulation
1541fs.cpp/match() used to treat the pattern "foo" as "foo*"
1541 DIR mode uses tmpfile() for opening temporary directory files
1541 D64 mode allows wildcards for selective directory reading
Increased compatibility of processor-level 1541 emulation in various places (C64<->1541 communication, VIA registers, memory map, disk change flag)
Inlined MOS6526::EmulateLine() and some small public functions of MOS6502_1541
New prefs option to enable/disable SID filter emulation
Joystick calibration is reset when joystick options change
BeOS: Self-calibrating joystick routines

V3.0h

Implemented SID notch filter, better resonance frequency calculation
Fixed bug with SID filter option
CIA timer B one-shot mode stops timer when counting undeflows of timer A
Implemented lightpen trigger
BeOS: Fixed for BeOS DR8, improved the GUI a bit
Unix: Some fixes to the TkGui (T64, SIDFilters, removed speed display)
Unix: Main window no longer resizable
Unix: SVGALib support works again

V3.1

BeOS: Joysticks work again

V3.1a

Frodo SC ported
Processor-level 1541 emulation supports reading GCR data, removed the faked job loop
Corrected ISB, RRA, SBX and SHA instructions
The last line of Y expanded sprites wasn't drawn
Light pen registers work
Small fixes to 1541d64/1541t64
CIA 2 PRA write: IEC lines respect DDRA
Better triangle waveform (12 bits)
SID emulation can play sampled sounds
New "Ignore SID Volume" prefs item for better sample playing
'*' on numerical keypad toggles speed limiter
BeOS: '/' on numerical keypad toggles processor-level 1541 emulation
BeOS: Safer quitting
BeOS: Option to use GameKit (screen)
BeOS: Replaced srand(system_time()) with srand(real_time_clock())
Unix: Sun makefile

V3.1b

Corrected SID sustain behaviour
Reading from write-only SID registers returns the last byte written to the SID
No more distortions when playing samples
Removed the "Ignore SID Volume" prefs item again
Combined SID waveforms now sampled from a 6581R4
Improved 1541 VIA timer operation
Fixed bug in 1541 head movement
Raster IRQs can be triggered by writing to $d011/$d012
Some changes for the MacOS port
Included autoconf stuff from Bernd
Frodo SC: Fixed some CIA timer bugs

V3.1c

Ported to AmigaOS
Fixed bug in IEC::Reset()
Fixed bug when writing to SID registers >24
The SID noise waveform should now sound the same on all platforms
Removed all calls to tolower() in SAM.cpp because of possible side-effects if tolower() is a macro
Drive LEDs are only updated once per frame
.d64/.t64 files are opened with read permissions only
Fixed bug with read_char buffering in 1541fs.cpp/1541t64.cpp
Frodo SC: Fixed memory trashing bug in MOS6569::draw_background()
Unix: Drive LEDs blink on error
Unix: Added more patches from Bernd

V4.0

The C64 ROM files are now included
Unix: Added SVGAlib keyboard patches from Bernd