Six WDC datasheets have been updated to their latest versions: W65C02S, W65C816S, W65C134S, W65C265S, W65C21, and W65C51N.

David Given's CP/M-65 operating system has also been added to the software section on that page. Unlike CP/M itself, David's system supports relocatable binaries to enable machines with incompatible memory maps to run the same programs. Ports of the system are available for several computers. This system developed using tools on a modern computer, with some portions being written in C.

A W65C265S datasheet dated December 1992 and a W65C816S datasheet dated July 1994 have been added to the Western Design Center (Older Versions) section of the documents archive.

A Developer Guide dated July 1994 has been added to the Western Design Center section of the documents archive.

A preliminary datasheet for the WDC W65C832 microprocessor dated March 1991 has been added to the Documents Archive. Thanks to Garth Wilson for providing the original for scanning.

Volume 1, Issues 8 and 9 of The PET Paper have been added to the Documents Archive.

The MOS Terminal Interface Monitor (TIM) Manual has been added to the Books section of the Documents Archive. Thanks to Bill Goble for donating the original for scanning.

Volume 0, Issue 5 (Incomplete) of the PET Users Group Newsletter has been added to the Documents Archive. Thanks to John Toebes for loaning it for scanning.

The Ensoniq 5503 Digital Oscillator Chip (DOC) datasheet has been added to the Documents Archive. Thanks to Bil Herd for loaning it for scanning.

Volume 9, Issue 3 of the ICPUG newsletter has been added to the Document Archive. Thanks to David Viner for scanning it.

The May 1979 issue of The Number Cruncher has been added to the Documents Archive. This was an internal company publication of Rockwell International with Commodore PET content.

Volume 1, Issues 1 and 2 of PET User Notes have been replaced with higher quality scans.

Volume 2, issue 1 of The PET Paper has been added to the Documents Archive. This PDF was made by retouching scans found on the commodore.ca website.

Volume 2, Issue 3 of The PET Paper has been added to the Documents Archive.

Volume 1, Issue 6 (August 1978) of The PET Paper has been replaced with a new PDF that adds missing pages. Thanks to Ethan Dicks for noticing this issue.

Volume 1, Issue 9 of the Commodore PET Users Club Newsletter is now available in the Documents Archive. Thanks to Ernie Chorny for providing the original and Steve Gray for scanning it.

Added a link to Brit Butler's cl-6502 emulator in the Emulators and Simulators section.

Added a link to "6502 Pages" to the SYM-1 Resources section.

Added a link to Seth Morabito's Symon simulator in the Emulators and Simulators section.

Add links to three more homebuilds in the Homebuilt Projects section.

Add section for 6502 test suites in the Emulators and Simulators section.

Update the descriptions of the Development and Emulators pages.

Add a section on HDL 6502 models in the Homebuilt Projects section.

Added links to new SBC project pages from BigDumbDinosaur and Dajgoro on the Homebuilt Projects page.

Added several new links to Garth Wilson's site on the Source Code page.

Removed several dead links and fixed others on the Homebuilt Projects page.

Added links to dev65 and cc65 on the Assemblers and Disassemblers page.

An older version of the MOS 6500-series datasheet (marked Preliminary and dated May 1976) is now available in the MOS section of the datasheets archive. Thanks to John Toebes for loaning us the original to scan.

Updated the link to Mertkan YILDIRIMLI's "My Little Simulator" on the Emulation and Simulators page. Thanks to both Mertkan and Ed Spittles for letting us know.

Updated the description of Piotr Fusik's XASM assembler on the Assemblers and Disassemblers section. XASM was previously DOS-only but is portable since version 3.0.0.

Updated the link to Halldor's 6502 project on the Homebuilt Projects page.

Added Virtual6502 to the Emulation and Simulator pages. Virtual6502 is a multi-purpose 6502 emulator for Win32, written by Rich Whitehouse.

Fixed the link to Sierra Circuit Design on the Commercial Resources page.

Added a new source code listing, Convert 32-bit Binary to ASCII Number String, to the Source Code Repository. Contributed by BigDumbDinosaur.

Fixed the link to RAE_E000.BIN on the SYM-1 Resources page. Thanks to George Leibman and Dallas Shell for finding the broken link.

Fixed line wrapping that broke assembly of the Intel HEX File Downloader listings in the Source Code Repository. Thanks to Garth Wilson for noticing this.

Added a new source code listing, Convert ASCII Number String to 32-bit Binary, to the Source Code Repository. Contributed by BigDumbDinosaur.

Added Jeff Laughton's KimKlone to the Homebuilt Projects section. The KimKlone is a computer that uses a standard 65C02 enhanced by off-chip circuitry. Its features include extensions that give it a 16MB address space and hardware acceleration for the Forth programming language.

Volume 0, Number 3 and Volume 0, Number 4 of the PET Users Group Newsletter, published by the University of California at Berekely's Lawrence Hall of Science under the Computer Project, are now available for download in the Documents Archive.

The first six issues of The PET Paper, published by ARESCO of Audubon, Pennsylvania, are now available for download in the Documents Archive.

The first issue of the Commodore PET Users Club Newsletter, an official Commodore publication, is now available for download in the Documents Archive.

A new tutorial on Decimal Mode has been contributed by Bruce Clark.

A new tutorial on 65C02 Opcodes has been contributed by Bruce Clark.

Added Py65, a 6502 simulator written in Python, to the Emulation and Simulators page.

An updated W65C02S datasheet (dated April 14, 2009) is now available in the WDC section of the datasheets archive.

An updated W65C22S datasheet (dated Jun 1, 2009) is now available in the WDC section of the datasheets archive.

Added Evatronix, an IP core developer and supplier, to the Commercial Support section.

Added Halldor's 6502 SBC Project Site to the Homebuilt Projects section.

Special thanks to Hans Otten who helped us correct many links on the Homebuilt Projects page.

A link to DOS/65, an interesting operating system with file system compatibility to CP/M-80, has been added to the Homebuilt Projects page.

A link to the Oric SDK has been added to the languages section of our tools listing. Thanks to Mickael Pointier for telling us about it.

A link to the 6502 Assembler & Emulator in JavaScript has been added to the emulators section of our tools listing. Thanks to Leslie Ayling for sending in the link.

Another JavaScript-based assembler and emulator, Virtual 6502, has been added to the emulators section of our tools listing. Thanks to Norbert Landsteiner for sending in the link.

The link to Erik van den Broeck's KIM-1 Page on the Simple Microcomputers and Trainers page has been updated. Thanks to Erik for letting us know.

Added the SYM-1 Supermon and audio cassette interface sources to the SYM-1 Resources page. Thanks to Lee Davison for contributing it.

The link to Chris Ward's 6502 Computer on the Homebuilt Projects page has been updated. Thanks to Chris for letting us know.

Nice reproductions of the 6526 CIA and 6545 CRTC datasheets are now available in the MOS Technology Datasheets. Thanks to Markku Alén for building these.

A link to the SYS8 Platform & Simulator been added to the emulators section of our tools listing. Thanks to Markku Alén for sending in the link.

A link to Mertkan YILDIRIMLI's My Little Simulator been added to the emulators section of our tools listing. Thanks to Mertkan for telling us about it.

Many additions and corrections have been made to the Book List thanks to Wilfred Bos.

The picoViewer interactive 6502 disassembler for PalmOS has been made available as a direct download from the assemblers and disassemblers section of our tools listing. Thanks to Shirley Chin of Picodoc Corporation.

Two new Synertek documents, "1981 Domestic Price List" and "Popular Microcomputer Products from Synertek" have been added to the Documents Archive. Thanks to Dallas Shell for contributing these.

A link to the CMD Obsolete Product Datasheets has been added to the Commercial Support area. Thanks to DiGGr for pointing it out.

A link to Grant's MicroUK101 has been updated in the Homebuilt Projects section. Thanks to Derek Peschel for finding it.

Paul Fellingham contributed a new mini-project for Clock Speed Switching.

The old "Supporting Materials" area of the site has been removed because we never received much useful content to put in it. We may bring it back in the future if good content becomes available for it.

The link to Samuel Falvo's Kestrel Project has changed. Samuel has built a small number of 65C816-based projects and his site provides schematics, software, and design documents.

Warren Moore's 6502 project pages have been taken offline and the link has been removed from the Homebuilt Projects section.

MATHPAC, an extension to KIMATH for the KIM-1, has been added to the Microcomputers & Trainers section. Thanks to Paul R. Santa-Maria for submitting it.

Dave Dixon sent in a link to Reverse Engineering the 6502. These Hungarian-only pages include high-resolution scans of the actual 6502 silicon and an impressive attempt to make a schematic from them.

Brian M. Phelps submitted a link to his project, S/O/S SyMon II, a 65(C)02 BIOS with a monitor and assembler. His pages contain photos and descriptions of several 6502 SBC projects along with documentation and software for S/O/S SyMon II.

Kevin Savetz submitted a link to Machine Language for Beginners, a book published in 1983 by Compute! Books to shows BASIC programmers how to program in 6502 machine language. It has now been made available online at AtariArchives.org with permission from the copyright holder.

Lee Davison has fully disassembled SYM-1 BASIC and made it available for download on his site.

Paul Zaleski sent in a link to Breadboard a Computer, J.B. Calvert's tutorial page that uses small 6504-based circuits to teach the fundamentals of a microcomputer system.

Doug Felton of Avocet Systems submitted updated company information for the Commercial Support page.

Mike Naberezny's 6504 SBC was slightly updated and has returned to the Homebuilt Projects section.

Dieter Müller's M02 project has been added to the Homebuilt Projects section. Dieter has built a homebuilt 6502-based project without a microprocessor IC or even FPGAs. Instead, he built his own 6502 work-alike using 40 ICs on two PCBs: mostly spare EPROMs and 74xx-series logic. The custom CPU has several improvements over the original 6502, such as a 16MB address range, most 65C02 opcodes, and some 65C816 features. The M02 computer includes a graphical LCD display and keyboard, and runs the KERNAL and BASIC ROMs from the Commodore 64.

Eugene Dorr has written a KIM-1 emulator for the Palm called vKIM ("Virtual KIM"). It is now linked in the Simple Microcomputers & Trainers section.

A link to Anton Treuenfels' cross assembler, HXA, has been added to assemblers list in the Cross-Development section.

The "MOS6500 Microcomputer Programming Manual" was submitted by both Antonio Giuliana and Mats Rosengren. It has been added to the book list.

Gary Becker's OSI-SOC has been added to the Homebuilt Projects section. Gary has built an enhanced OSI Superboard system in an FPGA. It currently features: 64x32 character, 8 color video on a VGA monitor, 40K main RAM memory, 8K BASIC in ROM, PS/2 keyboard that emulates the original matrix keyboard two 6850 UARTs, an enhanced monitor, and some tape software.

Jurgi submitted a Polish language book to the book list, "Asembler 6502".

A broken link to the Rockwell R65C21 PIA datasheet was fixed in the Documents Archive.

A new category, Application Notes, has been created in the Documents Archive. The first item to be place here is an application note called "The CMOS 6502": /documents/appnotes

Paul Beaupre has submitted the RAE Reference Card from the SYM-1 Users Group and it has also been added to the SYM-1 section of the Microprocessors & Trainers area.

Daryl Rictor's 65C816 converter, an adapter board to allow a 65C816 to be installed in a 6502 socket, has been added to the Hardware Mini-Projects section.

Mats Rosengren has expanded his Optimal Sort to sort large numbers of 16-bit elements. It can be found in the Sorting Algorithms section of the Source Code Repository.

Invector Embedded Technologies produces embedded controller boards including the IET6502SBC, a small SBC with a 65C02, 65C22, four-port UART, 128K RAM, ethernet controller, and connections for a graphical LCD display. A link has been added to the Commercial Support area.

Bruce Clark has submitted another contribution to the Tutorials and Primers section, this one explaining the sometimes mysterious Overflow (V) Flag.

Andrew Jabobs' Hexadecimal to Decimal Conversion routines have also been added to the Source Code Repository.

Fredrik Ramsberg's Shell Sort, an efficient sorting routine for large collections of 16-bit values, has been added to the Source Code Repository.

Marco Baye's ACME cross-assembler, an assembler supporting the 6502/65C02/65C816 that runs on several different platforms including DOS and Linux, has been added to the list of assemblers in the Cross-Development Tools area.

Warren Moore's 6502 Project has been added to the Homebuilt Projects list. This is Warren's first attempt at constructing a 6502-based computer and he chronicles his construction experience in a daily, illustrated log.

Carsten Strotmann's instructions for porting Sweet 16 have been added to the Source Code Repository. Sweet 16 is a metaprocessor or "pseudo microprocessor" implemented in 6502 assembly language. Originally written by Steve Wozniak and used in the Apple II, Sweet 16 can also be ported to other 6502-based systems to provide useful 16-bit functionality. This article includes the source code for Sweet 16, along with a brief history, programming instructions, and notes to help port it.

Daniel Wallner's T65 core has been added to the Homebuilt Projects section. The T65 is a free 6502 VHDL core that supports the 6502, 65C02, and 65C816 instruction sets. A reference SoC design is also provided, complete with ROM, RAM, and two 16450-compatible UARTs.

Toshi Morita has ported LCC to compile for the 65C816. It is now available for download, including source code for the compiler itself, from the Languages area of the Development Tools section.

Krzysztof Swiecicki's Projects have also been added to the Homebuilt Projects section. Krzysztof is a 6502 enthusiast from Poland. He has built some very interesting projects, including a 16450-based serial port, AD1848-based audio output, an SBC with an overclocked 65C02, and a fuel injection computer based on the 65SC816.

Sprow's MiniB has also been added to the Homebuilt Projects section. Smaller than a 3.5" floppy disk, its features include a 20x4 LCD display, 128K Flash ROM, a Real Time Clock, and a programmable logic device.

There is now a wealth of Synertek SYM-1 information in the new SYM-1 Resources section. Special thanks to Leland Goertz, René Sommerlatt, and Dallas Shell for this material.

In addition to the new SYM-1 section, the Datasheets Archive now contains several new Synertek documents, including a 318-page full databook from 1981-1982!

Datasheets for Commodore Semiconductor Group (CSG)'s 6508, 6509, 6510, and 65245 have been added to the Datasheets Archive. Thanks to Rich Cini for scanning these to PDF format.

Adam Luoranen's 6502-based projects have been added to the Homemade Computers & Hardware Projects section. Adam's projects include a simple LED-blinker and interfacing a KS0108-based graphical LCD panel.

Peter Jennings' famous MicroChess game has also been added to the Source Code Repository, along with a modified version by Daryl Rictor for use over a 6551-based serial port.

The Maniac II has also been added to the Homemade Computers & Hardware Projects section. This site by Tomasz Piotrowski has pictures and details about the Maniac II, an impressive compact 65C816 computer with keyboard and LCD screen that resembles a small laptop.

Vern Graner's KIM-1 Enthusiasts Page has been added to the Simple Microcomputers and Trainers section. Vern's site for KIM-1 users includes documents, programs, and a photo gallery.

Nurettin TOPALOGLU's Turkish book, "Mikroislemciler ve Assemby Dili", has been added to the Book List.

Piotr Fusik's pages are once again hosted on 6502.org. Piotr's pages feature xasm, a cross-assembler for DOS.

Dan Boris's 6502 Processor Page has moved. Thanks to ArchieR for providing the update.

Daryl Rictor has authored a set of X-Modem file transfer routines for 6502-based computers with a 6551 serial port. They have been added to the Source Code Repository.

Paul R. Santa-Maria's SBC&Apple II Resources have moved and the link in the Enthusiasts' Pages has been updated.

Sam Bergmans has created SB-Assembler, a DOS macro assembler with some interesting features like a random fill directive and multi-processor support. It is now linked in the Assemblers&Disassemblers area of the Cross-Development section.

Michael Chapman Martin has created a highly-portable 6502 cross-assembler written entirely in Perl. The P65 Assembler has been added to the Assemblers&Disassemblers area.

Thomas Dettbarn submitted a link to PSALM, a German-only page describing a project that reverse-engineered the 6502 and produced an asynchronous version in VHDL. The link has been added to the Homebuilt Projects on the Web list.

Charles R. Bond now has KIMATH, one of the first high-quality floating point math packages, available for download from his website complete with documentation. It is now listed in the KIM-1 area of the Simple Microcomputers and Trainers section.

Soft6502 is a 6502 simulator for Windows by Charles R. Bon. It resembles early 6502-based computers like the KIM-1 and can now be found in the Generic 6502 Emulation and Simulators area of the Cross-Development section.

Charles R. Bond's Assembler has also been added to the Assemblers and Disassemblers list.

Erik Van den Broeck's pages now contain the entire text of The First Book of KIM and MICROCHESS by Peter Jennings. It is also linked in the Simple Microcomputers and Trainers section.

David Brown has written an impressive Microtan65 Emulator that is now linked in the Simple Microcomputers and Trainers section. Thanks to Dougie Lawson for this and other links.

Ross Archer's KIM-1 Repository has also been added to the Simple Microcomputers and Trainers section.

Ian Pun's KIM-1 Pages have also moved and the link in the Simple Microcomputers and Trainers section has been updated.

The 6502 Webring addresses have also been changed and are now functional again.

Added RICE65, a 65C02 In-Circuit-Emulator from I-Pal Communications, to the Commercial Support page.

Added AS65, Frank Falstaff's two-pass 6502/65C02 assembler for DOS, to the Assemblers page in the Cross-Development section.

Lee Davison now has a new webpage showcasing his 6502 projects. It is also the new home of his BASIC interpreter, EhBASIC. The link has been added to the Homebuilt Projects section.

Floating Point Routines from Steve Wozniak and Roy Rankin have been also been added to the Source Code Repository thanks to Paul R. Santa-Maria.