News and Site Updates  Projects  Code  Documents  Tools  Forum
13 Nov 2022 A new Application Brief from Commodore Semiconductor Group, #5 Dual Processor Configuration with the MPS 6508, has been added to the Documents Archive. Thanks to Frank Hughes for providing the original.
 
8 Nov 2022 A reconstructed version of Lee Davison's website, formerly hosted at http://mycorner.no-ip.org, is now available on 6502.org. Lee passed away on September 21, 2013.
 
7 Nov 2022 Dietrich Lausberg's CPM-65 operating system has been added to the software section on the Homebuilt Projects page. Full assembly language source code for this CP/M-derived operating system is available, including an assembler, BASIC, FORTH, and many utility programs. This system is very complete and can assemble itself.

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.

 
25 Oct 2022 A copy of Andrew Jacobs' website, formerly hosted at www.obelisk.me.uk and before that www.obelisk.demon.co.uk, is now available on 6502.org. Andrew passed away on January 8, 2021.
 
12 July 2022 Added a link to James Salvino's 6502Asm assembler to the Development Tools page.
 
17 June 2022 Two off-site links to macros have been removed from the Soure Code section as they are not assembly language routines, which is what the page was originally intended to collect. The links were removed in response to a user request that even more macros be added. Instead, the page has been returned to its original purpose.
 
3 Oct 2020 Added Heiko Pruessing's MARVIN-1 project to the Homebuilt Projects section.
 
1 Jun 2020 A preliminary datasheet for the WDC W65C365 microcontroller dated March 1991 has been added to the Western Design Center section of the documents archive. Thanks to Garth Wilson for providing the original for scanning.

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.

 
29 Aug 2019 The December 1981 issue of PRINTOUT has been replaced with a new PDF that fixes two missing pages.
 
26 Aug 2019 The October-November 1978 issue of PET Gazette has been added to 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.

 
7 May 2019 Mike Barry provided a new version of the Print Immediate (PRIMM) routine for the 65C02 that is short and preserves the Y register.
 
16 Oct 2018 A link to the 6502bench SourceGen disassembler has been added to the Development Tools page.
 
11 Oct 2018 Added new 2018 versions of the W65C02S and W65C816S datasheets to the Documents Archive. Thanks to Garth Wilson for pointing them out.
 
24 Apr 2018 Added the MOS Technology 65E4 Final Design Specification, an internal document describing a 6502 successor that was never produced, to the Documents Archive. Thanks to Frank Hughes for providing it.
 
24 Apr 2018 Added the Rockwell R6500/1E datasheet to the Documents Archive. Thanks to Frank Hughes for providing the scan.
 
11 Apr 2018 A link to RCC16 has been added to the Compilers and Languages section. Thanks to Paul Womack for submitting it.
 
26 Mar 2018 A link to the asmx assembler has been added to the Development Tools page.
 
23 Mar 2018 A Synertek SY6500 Microprocessor Products datasheet dated April 1979 has been added to the Synertek section of the Documents Archive. Thanks to Josh Bensadon for scanning it.
 
15 Mar 2018 Added the complete 1981 Data Catalog to the MOS Technology section in the Documents Archive. Thanks to Frank Hughes for providing the originals.
 
10 Mar 2018 Added more MOS Technology datasheets: 6500, 6500/1, 6520, 6523, 6525, 6530, 6532, and 65245. Thanks to Frank Hughes for providing the originals.
 
8 Mar 2018 Added MOS Technology datasheets for the 2316, 2332, and 2364 ROMs. Thanks to Frank Hughes for providing the originals.
 
6 Mar 2018 Seven Application Briefs from Commodore Semiconductor Group have been added to the Documents Archive. Thanks to Frank Hughes for providing the originals.
 
28 Feb 2018 A cover page has been added to the MOS 6509 datasheet to warn that the pinout contains an error.
 
26 Feb 2018 A MOS Technology 6526 CIA datasheet dated March 1981 has been added to the MOS datasheets section of the Documents Archive. Thanks to Frank Hughes for scanning it.
 
14 Feb 2018 Volume 14 of Dr. Dobb's Journal has been added to the Documents Archive.
 
26 Dec 2017 Added Marek Karcz's VM6502 emulator to the Emulators and Simulators section.
 
28 Oct 2017 Efficient Nybble Swap has been added to the Source Code Repository.
 
18 Sep 2017 Volume 15 of Dr. Dobb's Journal has been added to the Documents Archive.
 
27 Sep 2017 The Summer 1979 issue of PET Gazette in the Documents Archive has been replaced with a new PDF that adds four missing pages.
 
26 Sep 2017 Volume 1, Issues 3, 6, and 10 of the Commodore PET Users Club newsletter have been added to the Documents Archive.
 
18 Sep 2017 Volume 7 of Dr. Dobb's Journal in the Documents Archive has been replaced with a new PDF that adds several missing pages.
 
19 Jun 2017 Fixed the link to SYM1_1.BIN on the SYM-1 Resources page. Thanks to Paul Beaupre for finding the broken link.
 
22 Apr 2017 Added Gianluca Ghettini's mos6502 emulator to the Emulators and Simulators section.
 
7 Apr 2017 Added Paul Gardner-Stephen's GS4502B project to the Homebuilt Projects section.
 
5 Apr 2017 Updated the VTL-02 article in the Source Code Repository.
 
2 Mar 2017 Updated the description of WFDis disassembler in the Development Tools page.
 
8 Feb 2017 Added several web-based assemblers and IDEs to the Development Tools page.
 
6 Feb 2017 Added BeebAsm to the Development Tools page.
 
28 Jan 2017 Added the Radix 256 Counting Sort by Dwight Elvey to the Source Code pages.
 
10 Jan 2017 Dieter Müller's pages have been updated.
 
21 Dec 2016 A Synertek SY6522 VIA datasheet dated January 1978 has been added to the Synertek datasheets section of the Documents Archive.
 
21 Dec 2016 The complete Synertek 1978 Data Catalog has been added to the Synertek datasheets section of the Documents Archive.
 
19 Dec 2016 The complete GTE Microcircuits 1984 Data Book has been added to the CMD/GTE datasheets section of 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.

 
13 Dec 2016 The 65c816 Interrupts tutorial has been updated, with permission.
 
8 Dec 2016 The G65SCxxx CMOS 8-bit Microprocessor Family datasheet has been added to the CMD/GTE datasheets section of the Documents Archive.
 
7 Nov 2016 Andrew Holme's phase-accurate HDL core has been added to the Homebuilt Projects section.
 
18 Sep 2016 Volume 12 of Dr. Dobb's Journal has been added to the Documents Archive.
 
12 Sep 2016 Added errata section to Bruce Clark's Decimal Mode tutorial.
 
14 Aug 2016 Link to Codebase 64 wiki has been added to the Source Code Repository.
 
1 Aug 2016 Link to GCC port has been added to the Compilers and Languages section.
 
23 Jul 2016 Issues 57, 58, and 59 of geoNEWS have been added to the Documents Archive. Thanks to Andrew Fisher for scanning them.
 
1 Jul 2016 Assembly Lines: The Complete Book has been added to the Book List.
 
29 May 2016 Alan Daly's improved 65C02 core has been added to the Homebuilt Projects section.
 
28 Apr 2016 Added the MOS Technology 6567 VIC-II datasheet to the Documents Archive. Thanks to Steve Gray for providing it.
 
13 Apr 2016 Added the Rockwell R65F11/R65F12 and R65FRx/R65FKx datasheets to the Documents Archive. Thanks to J.C. Wren for providing them.
 
12 Apr 2016 An undated Synertek datasheet, SY6500 Microprocessors, has been added to the Documents Archive.
 
11 Apr 2016 The Western Digital WD9914 GPIB Controller datasheet has been added to the Documents Archive. Thanks to Garth Wilson for donating the original for scanning.
 
29 Mar 2016 Volume 1, Issues 4/5, 7, and 8 of the Commodore PET Users Club newsletter have been added to the Documents Archive.
 
28 Mar 2016 Several disassemblers have been added to the Development Tools section.

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.

 
27 Mar 2016 Volume 1 of Dr. Dobb's Journal has been replaced with a new PDF. It fixes two pages that were in the wrong order.

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

 
21 Mar 2016 The Calc65 floating point arithmetic and transcendental function package has been added to the Source Code Repository.
 
20 Mar 2016 Volume 7, Issue 5 of the ICPUG newsletter has been added to the Document Archive. Thanks to David Viner for scanning it.
 
18 Mar 2016 The MCS 6500 Family Programming Manual in the Documents Archive was incomplete. It has been replaced with a new scan by Rich Cini.
 
13 Mar 2016 Several websites hosting 6502 discussions have been added to the Discussion Groups section.
 
10 Mar 2016 Issues 62, 63, and 64 of geoNEWS have been added to the Documents Archive. Thanks to Andrew Fisher for scanning them.
 
28 Feb 2016 Volume 7, Issue 2 of the ICPUG newsletter has been added to the Document Archive. Thanks to David Viner for scanning it.
 
27 Feb 2016 Volume 5, Issue 6 and Volume 6, Issue 6 of the ICPUG newsletter have been added to the Document Archive. Thanks to David Viner for scanning them.
 
1 Feb 2016 The Western Digital Storage Products Handbook (June 1984) has been added to the Documents Archive. Thanks to Garth Wilson for donating the book.
 
8 Jan 2016 A collection of embedded emulators on microcontrollers has been added to the Emulators and Simulators section.
 
29 Dec 2015 Volume 5, Issues 3 and 5 of the ICPUG newsletter have been added to the Document Archive. Thanks to David Viner for scanning them.
 
26 Oct 2015 Issues 1-75 of The Zero Page, the newsletter of the Commodore Users of Wichita, has been added to the Documents Archive. Thanks to Dale Lutes for scanning them.
 
25 Oct 2015 Issues 50, 56, 60, and 61 of geoNEWS have been added to the Documents Archive. Thanks to Dale Lutes for scanning them.
 
24 Oct 2015 Volume 5, Issue 4 of the ICPUG newsletter has been added to the Document Archive. Thanks to David Viner for scanning it.
 
23 Oct 2015 Issues 65-88 of geoNEWS, a publication of the UK-based geoCLUB that supported GEOS on Commodore computers, has been added to the Documents Archive. Thanks to Kevin Steele for scanning them.
 
13 Oct 2015 The complete 1981 and 1982 years of the ICPUG newsletter, published by the Independent Commodore Products Users Group, have been added to the Document Archive. Thanks to David Viner for scanning them.
 
10 Oct 2015 SPOT, the Society of PET Owners and Trainers, has been added to the Documents Archive. SPOT covered the early years of Commodore PET computers. It was first published in the People's Computers newsletters and then in Recreational Computing magazine. Thanks to Harry Saal, the former editor of SPOT, for providing these extracts.
 
5 Oct 2015 The Summer 1979 issue of PET Gazette has been added to the Documents Archive.
 
4 Oct 2015 The Spring 1979 issue of PET Gazette has been added to the Documents Archive.

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.

 
3 Oct 2015 Mike Barry's port of VTL-2 in the Source Code Repository is updated to revision B, adding bitwise operators, peek and poke, and supporting indentation.

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.

 
2 Oct 2015 Added a guide to 65C816 opcodes by Bruce Clark to the Tutorials and Primers section.
 
30 Sep 2015 The March 1983 issue of PRINTOUT has been replaced with a new PDF where page 23 is not damaged.
 
28 Sep 2015 Volume 11 of Dr. Dobb's Journal has been added to the Documents Archive.
 
23 Sep 2015 The March, June, August, and December 1982 issues of PRINTOUT have been added to the Documents Archive.
 
18 Sep 2015 The December 1987 issue of Commodore Computing International has been added to the Documents Archive.
 
16 Sep 2015 Selected 6502-related articles from Dr Dobb's Journal have been added to the Documents Archive.
 
11 Sep 2015 Volumes 8-10 and 13 of Dr. Dobb's Journal have been added to the Documents Archive.
 
10 Sep 2015 Mike Barry's port of VTL-2 is now available in the Source Code Repository.
 
6 Sep 2015 Dieter Müller's pages have been updated with a new design, X02, which is an experimental 6502 compatible CPU.
 
2 Sep 2015 Volumes 1-7 of Dr. Dobb's Journal have been added to the Documents Archive.
 
7 Aug 2015 The May, July, September, October, and November 1982 issues of PRINTOUT have been added to the Documents Archive. These PDFs were made from images that had been posted on the World of Spectrum website and were found by David Viner.
 
4 Aug 2015 The March and April 1983 issues of PRINTOUT have been added to the Documents Archive. Thanks to David Viner for scanning them.
 
2 Aug 2015 All issues of MICRO: The 6502 Journal have been replaced with new PDFs that have OCR behind the images.
 
31 Jul 2015 MOS Technology preliminary datasheets dated August 1975 for the 650x microprocessors and 6530 RRIOT have been added to the Documents Archive. The PDFs were made from scans found on the Fountainware 6502 Memorabilia page.
 
25 Jul 2015 The February 1983 issue of PRINTOUT has been added to the Documents Archive. Thanks to David Viner for scanning it.
 
24 Jul 2015 The Fall 1986 issue of CBUG Escape has been added to the Document Archive.
 
15 Jul 2015 The December 1979 through June 1981, December 1981, and January 1983 issues of PRINTOUT, a Commodore PET magazine, have been added to the Document Archive. Thanks to David Viner for scanning them.
 
4 Jun 2015 All issues of AIM Interactive have been replaced with new PDFs that have OCR behind the images.
 
2 Jun 2015 Added a new datasheet for the Rockwell R65C00/21 Dual CMOS Microcomputer and R65C29 Dual CMOS Microprocessor. Thanks to Jeff Laughton and Garth Wilson for submitting it.
 
27 May 2015 Volume 3, Issue 1 of the ICPUG newsletter has been added to the Document Archive. Thanks to David Viner for scanning it.
 
23 May 2015 Commodore Club News Volume 3, Issues 4-11 and Volume 4, Issue 1 have been added to the Documents Archive. Thanks to David Viner for scanning them.
 
22 May 2015 All of the California Micro Devices (GTE) datasheets have been replaced with new PDFs that have the images deskewed and OCR behind the images.
 
18 May 2015 The Rockwell R65C52, R6549, R6545-1, R6531, R6530, R65C24, R6522, R65C21, and R6520 datasheets have been replaced with new PDFs that have the images deskewed and OCR behind the images.
 
15 May 2015 All of the MOS Technology datasheets have been replaced with new PDFs that have the images deskewed and OCR behind the images.
 
9 May 2015 Fourteen issues of Commodore Computing International have been added to the Documents Archive. Thanks to David Viner for scanning them.
 
17 Mar 2015 Volume 3, Issues 6 through 10 and Volume 4, Issues 1 through 4 of The PET Paper are now available in the Documents Archive. Thanks to Ernie Chorny for providing the originals and Steve Gray for scanning them.
 
16 Mar 2015 All issues of SuperPET Gazette in the Documents Archive have been replaced with new PDFs that have OCR behind the images.
 
15 Mar 2015 Volume 3, Issues 1 through 5 of The PET Paper are now available in the Documents Archive. Thanks to Ernie Chorny for providing the originals and Steve Gray for scanning them.
 
12 Mar 2015 "Best of the PET Gazette" is now available in the Documents Archive. Thanks to Ernie Chorny for providing the original and Steve Gray for scanning it.

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.

 
10 Mar 2015 Volume 1, Issue 2 of the Commodore PET Users Club Newsletter is now available for download in the Documents Archive. Thanks to Ernie Chorny for providing the original and Steve Gray for scanning it.
 
9 Feb 2015 Datasheets for the WDC W65C02S, W65C134S, and W65C51N have been updated in the WDC section of the datasheets archive.
 
27 Jan 2015 Added Dirk Grappendorf's mobile home computer to the Homebuilt Projects section.
 
27 Jan 2015 Added m6502 emulator by Chad Page to the Emulators and Simulators section.
 
31 Dec 2014 Added Steckschwein, a 65C02-based homebuilt computer, to the Homebuilt Projects section.
 
11 Dec 2014 Added Ariejan de Vroom's i6502 emulator to the Emulators and Simulators section.
 
4 Nov 2014 Added Saturn Software Limited documents (SK-FORTH79, SYM-PASCAL, and X-RAY) to the Synertek SYM-1 Resources pages. Contributed by Phillip Musumeci.
 
19 Oct 2014 Added documentation for the perSYMone FDC-1 Floppy Disk Controller to the Synertek SYM-1 Resources pages. Contributed by Andrew Dunn.
 
31 Jul 2014 We are very sad to report that Lee Davison (leeeeee) has passed away.
 
12 June 2014 Added a link to Paul Annesley's go6502 emulator to the Emulators and Simulators section.
 
29 May 2014 Added a link to Aaron Mell's 6502Net emulator to the Emulators and Simulators section.
 
17 May 2014 Added Seth Morabito's 6502 SBC and Andy Vorontsov's RW6HRM 6502 SBC to the Homebuilt Projects section.
 
17 Apr 2014 Added InfoWAT volume I numbers 3 through 8 to the Documents Archive. Thanks to Michael Cook for loaning the originals for scanning. Please contact us if you have any additional issues of InfoWAT or WATCOM News.
 
15 Apr 2014 Added SuperPET Gazette volume II numbers 5, 6, and 9 to the Documents Archive. Thanks to Michael Cook for loaning the originals for scanning.
 
9 Nov 2013 Added a new tutorial on 65C816 by BigDumbDinosaur to the Tutorials and Primers section.
 
17 Oct 2013 Added version 2 of BigDumbDinosaur's W65C816 String Manipulation Library to the Source Code section.
 
8 Oct 2013 Fixed the download link for TASM on the Assemblers and Disassemblers page. Thanks to Bryant Keller for finding the broken link.
 
6 Oct 2013 Added the W65C134S and W65C265S monitor ROM manuals and listings to the WDC section of the datasheets archive.
 
15 Jul 2013 Added BigDumbDinosaur's W65C816 String Manipulation Library to the Source Code section.
 
13 Jul 2013 Added Dieter Müller's DRC2 to the Homebuilt Projects section.
 
12 Jul 2013 Dieter Müller's pages have been updated.

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

 
29 Jun 2013 Added Marco Granati's MB01 to the Homebuilt Projects section.
 
16 Apr 2013 Added a link to the Ophis assembler to the Development Tools section.
 
6 Jan 2013 Added a link to Don Buska's SYM-1 pages to the SYM-1 Resources section.

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

 
5 Jan 2013 Added most issues of CBUG Escape, the newsletter of the Chicago B128 Users Group, to the Documents Archive. Thanks to Bill Degnan and Steve Gray for loaning the originals for scanning. If you have issue 6, issue 11, or any other CBUG materials, please contact us.

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

 
2 Dec 2012 Several issues of Northwest Computer News are now available in the Documents section. Thanks to Derrick Brundage for loaning the originals.
 
4 Nov 2012 We are very sad to report that Tony Gonzalez (Nightmaretony) passed away today.
 
2 Nov 2012 Correct two mistakes in the 6502 opcode timings.
 
11 Oct 2012 Link to two 6502-related mailing lists and a Google Plus page on the Discussion Groups page.

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.

 
21 Sep 2012 Fix up link to Grant Searle's UK101 page in the Homebuilt Projects section.
 
25 Aug 2012 Added a link to Nick Morgan's Easy 6502 website in the Emulators and Simulators section.
 
19 Aug 2012 Added a link to the Acheron VM project on the Homebuilt Projects section.
 
14 Aug 2012 Added a link to BigDumbDinosaur's 65C816 macros for Michal Kowalski's 6502 Macroassembler and Simulator on the Source Code page.

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

 
12 Aug 2012 Added links to Garth Wilson's 6502 Primer, RS-232 Primer, and Tip of the Day to the Tutorials & Primers page.

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

 
6 Aug 2012 Fixed links for T65 and Free-6502 on the Homebuilt Projects page.
 
5 Aug 2012 Fixed link to The Microtan65 Page on the Simple Microcomputers and Trainers page.
 
4 Aug 2012 Fixed links to ACME and WLA DX on the Assemblers and Disassemblers 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.

 
3 Aug 2012 The source code for the website is now available in a public repository on GitHub. If you would like to contribute to the site directly, you can fork the repository on GitHub and then send pull requests with your changes.
 
27 May 2012 Added a new datasheet for the Rockwell 65C24 PIAT.
 
24 May 2012 The forum is back after a week of downtime.
 
18 Feb 2012 Added the SYM-1 version of "Microprocessor Fundamentals, a Short Course for Scientists and Engineers" to the Books section of the Documents Archive. Thanks to Andrew Lankford for sending an original copy.
 
3 Jan 2012 Fixed links to Lee Davison's website.
 
2 Jan 2012 Fixed the link to Michal Kowalski's 6502 Macroassembler and Simulator.
 
4 Apr 2011 Volume 0, Numbers 0 though 2 of the PET Users Group Newsletter are now available for download in the Documents Archive. Number 2 is incomplete, please contact us if you have it or any other issues.
 
18 Dec 2010 Updated all of the Western Design Center datasheets in the Documents Archive to newer versions. Thanks to BigDumbDinosaur for noticing the updates on the WDC website.
 
26 Nov 2010 Added most Volume II issues of SuperPET Gazette to the Documents Archive. Thanks to John Toebes for loaning the originals and assistance with scanning. We are still missing the following issues from Volume II: Number 5, Number 6, Number 9. Please contact us if you have these issues.

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.

 
20 Nov 2010 Added a new link to the Visual Transistor-level Simulation of the 6502 CPU on the Emulation and Simulators page.

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.

 
13 Nov 2010 SuperPET Gazette, all of Volume 1 and the first issue of Volume 2, are now available from the Documents Archive. Thanks to Barry Bogart for loaning the originals for scanning.
 
3 Apr 2010 Added a link to ReCo6502, John Kortink's remake of the Acorn 6502 Second Processor, on the Homebuilt Projects page.

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.

 
28 Mar 2010 Updated links to Adam's Great 6502 Projects, Daniel's T65, Pete's Robot, and Roland's Atom-in-PC on the Homebuilt Projects 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.

 
3 Jan 2010 PET User Notes volume 1, issue 7 is now available from the Documents Archive.

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.

 
1 Nov 2009 Several additional issues of PET User Notes are now available from the Documents Archive.
 
2 August 2009 Dieter Müller's pages are now hosted on 6502.org. 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.
 
26 July 2009 MICRO issues 44, 45, 46, and 47 are now available from the Documents Archive.
 
25 July 2009 MICRO issues 24 and 43 are now available from the Documents Archive.
 
28 June 2009 MICRO issue 65 is now available from the Documents Archive. Thanks to Ken Sumrall and Richard Cini for contributing it.

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

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

 
20 June 2009 An updated W65C816S datasheet (dated June 18, 2009) is now available in the WDC section of the datasheets archive.

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

 
11 June 2009 An updated W65C816S datasheet (dated June 10, 2009) is now available in the WDC section of the datasheets archive.

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.

 
18 May 2009 Updated the link to Sheldon Simms' Sim65 simulator. Thanks to Ed Spittles for pointing it out to us.
 
20 Apr 2009 Added the MOS 6500/1 One-Chip Microcomputer datasheet to the Datasheets Archive. Thanks to Richard Cini, whose website was the original source for this datasheet.
 
14 Apr 2009 Added Sitronix to the Commercial Support page. Thanks to Oscar Lindberg for letting us know about them.
 
21 Mar 2009 Added Joachim Deboy's 65816 Projects to the Homebuilt Projects section.

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.

 
1 Mar 2009 Added Enhanced Day of the Week to the Source Code Repository. Thanks to W.J. Brier for this submission.
 
9 Jan 2009 Added a link and mirror of Ian Piumarta's lib6502 to the Emulators page of the Development Tools section. Thanks to Ed Spittles for letting us know about it.
 
5 Oct 2008 Updated datasheets for all Western Design Center parts are now available in the datasheets archive.

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

 
20 Sep 2008 MICRO issue 53 and Compute II issue 3 are now available from the Documents Archive. Thanks to Bill Degnan for loaning us the originals for scanning.
 
7 Aug 2008 MICRO issues 21 though 23 are now available from the Documents Archive.
 
22 Jul 2008 MICRO issues 26 though 30 are now available from the Documents Archive.
 
7 Jul 2008 A link to DASM, a cross-platform macro assembler, has been added to the Assemblers and Disassemblers 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.

 
30 Jun 2008 A large number of CompuKit UK101 documents have been added to the Documents Archive. Our thanks to Neil Chadderton for scanning them.
 
26 Jun 2008 If you are interested in acquiring a Compukit UK101, check out this eBay auction. We don't normally post this kind of announcement but the seller was kind enough to send us scans of the documentation for inclusion on 6502.org. Thanks.
 
19 Jun 2008 A new book, "6502 Machine Code for Humans", has been added to the Book List. Thanks to Adam Trionfo for pointing it out.

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.

 
17 Jun 2008 Registration for the forum is open again after being temporarily disabled due to spam problem. We've added some measures to help prevent forum spam in the future.
 
25 May 2008 6502.org is now the official home of iDOC=, the Commodore documentation archive, that was previously run by Peter Karlsson for many years. Its new location is cbm.6502.org.
 
18 May 2008 The link to Sunplus Technology on the Commercial Support page has been updated. Thanks to Lee Davison for pointing it out.
 
13 Jan 2008 The comp.sys.org newsgroup has been added to the Discussion Groups page. Thanks to Mike Brown for letting us know about it.
 
3 Dec 2007 Bruce Clark's tutorial, The Overflow (V) Flag Explained, has been updated to include a short story about the SO pin from former Commodore engineer Bil Herd.
 
22 Nov 2007 Several SYM-1 links have been corrected on the site. Thanks to Dwight Elvey for pointing these out.
 
11 Nov 2007 We've updated a number of different areas of the site, including pages that have not been updated in some time like Development Tools and Simple Microcomputer and Trainers. We will be continuing updates throughout the week, so please let us know if you have any issues.
 
10 Nov 2007 Daryl Rictor has submitted a new datasheet for the Rockwell R6501Q One-Chip Microprocessor. It has been added to the Rockwell section of the Datasheets Archive.
 
7 Nov 2007 A small error has been corrected in the NMOS 6502 Opcodes tutorial. Thanks to David Wilson for noticing this.
 
11 Oct 2007 Simon Jansen has built a replica of Bender, a robot character from the television series Futurama. In addition to brewing beer, Simon's project includes a 6502 SBC with IR control and audio playback. It has been added to the Homebuilt Projects section.
 
7 Oct 2007 MICRO Magazine issues 61-76 are now available in the Documents Archive. Thanks again to Richard Cini for contributing these.
 
22 Jul 2007 Datasheets for several Motorola line drivers and receivers often used on 6502-based equipment has been added to the Documents Archive. Thanks to Garth Wilson for contributing these.

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.

 
20 Jul 2007 MICRO Magazine issues 7-10 are now available in the Documents Archive. Thanks to Richard Cini for contributing these.
 
1 Jul 2007 Richard Cini has contributed several complete books to the Documents Archive. The titles are KIM Hints, KIM-1 User Manual, First Book of KIM, MCS6500 Family Hardware Manual, and MCS6500 Family Programming Manual.
 
24 Jun 2007 Paul Fellingham has contributed a new mini-project that shows how to build a priority interrupt encoder with minimum interrupt level masking.
 
21 Jun 2007 "Microprocessor Fundamentals, a Short Course for Scientists and Engineers" was contributed by Steven Stengel and added to the Documents area. This is a 244-page introductory course designed to be used with the KIM-1. It teaches beginning logic and hardware basics up through number systems and software design. The appendices contain KIM-1 software, TTL reference sheets, MOS datasheets, and more.
 
5 May 2007 Larry Wells contributed the GTE datasheet for the G65SC802/G65SC816 microprocessors, dated April 1985. It can be found in the Datasheets Archive area for CMD/GTE.

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.

 
19 Dec 2006 Links to projects from Dieter Müller and PSALM have been updated on the Homebuilt Project page. Thanks to Dieter Müller for reporting them.
 
11 Nov 2006 The 6502.org Forum has moved to http://forum.6502.org. Please update your bookmarks.

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.

 
7 Sep 2006 Updated datasheets are now available for the G65SC02, G65SC21, G65SC22, G65SC51, G65SC150, and G65SC151 from California Micro Devices (GTE). They are now available in the Documents Archive. Thanks to Ronald van Dijk for finding them.
 
6 Sep 2006 The datasheet for the Rockwell R6511Q One-Chip Microprocessor&R6500/13 One-Chip Microcomputer has been added to the Documents Archive. Thanks to Ken Sumrall for scanning it.
 
25 Aug 2006 Richard Cini has scanned nine new issues of MICRO Magazine. Issues 31 through 39 have been added to the Documents Archive.
 
9 Jul 2006 RDY Generation for CMOS 65C02 Microprocessors has been added to the Hardware Mini-Projects section. Andre Fachat describes a generic schematic for generating the RDY line used by the 65C02 microprocessor to hold bus accesses when a device is not ready.
 
29 Jun 2006 6502.org has completed its move to a new server provided by Mike Naberezny. The new server will provide increased bandwidth, storage, and allow for more new features to be added to 6502.org. We'd like to very sincerely thank Ross Archer who has generously donated the previous hosting for the past few years.
 
3 Dec 2005 Ryan's Nixie Clock has been added to the Homebuilt Projects section. Ryan Brooks has built a Nixie tube clock that is driven by a 6502 with 8K RAM, 8K EPROM, and a 6522 VIA. The RAM used is a Dallas DS1742, which also acts as the real time clock. His page includes photos, schematics, and source code.
 
14 Aug 2005 Samuel Falvo's Kestrel 1p3 has been added to the Homebuilt Projects section. This 65C816-based project includes 32K RAM, and a 65C22 for I/O. This computer has no ROM, instead it includes an "IPL" (Initial Program Load) port that a host computer uses to take control of the busses and write the program into RAM.

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.

 
6 Aug 2005 Rafal Szyja submitted another Polish language book to the book list, "Mikroprocesor 6502 i jego rodzina".

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.

 
1 Aug 2005 Brian Lyons submitted Synertek's Application Note AN3 on the 6545 CRT Controller, which was scanned by Richard Cini. It has been added to the Application Notes 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.

 
24 Jul 2005 Esa Vesalainen submitted two books to the book list, "Teach Yourself Assembler 6502" and "Assembler Routines for the 6502".

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.

 
30 May 2005 Antonio Pedreira Rios has submitted the datasheet for the Rockwell R6531 RRIOC (ROM-RAM-I/O-Counter). It can now be found in the Rockwell section of the Datasheets Archive.
 
25 Apr 2005 The datasheets for the Rockwell CMOS parts have been added. Datasheets are now available for the R65C02/102/112, R65C19, R65C21, and R65C52: /documents/datasheets/rockwell

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

 
2 Apr 2005 André Fachat has updated his O65 Binary Relocation Format, and this page now contains a draft for version 2.0 of the format.
 
5 Feb 2005 Shell Sort (for 16-bit Elements) by Fredrik Ramsberg has been improved and now also contains an implementation of the Insertion Sort.
 
5 Feb 2005 Linear Congruential Pseudo-Random Number Generator Routines, a set of routines by Bruce Clark for generating pseudo-random numbers, has been added to the Source Code Repository.
 
5 Feb 2005 A dead link to the VAutomation 6502 synthesizable core was removed from the Commercial Support area. Thanks to Peter Crossley for pointing this out. If anyone has an updated link, please forward it to us.
 
31 Jan 2005 In Zero-Overhead Forth Interrupts, Garth Wilson shows how to efficiently service interrupts in high-level Forth on indirect-threaded Forth systems.
 
30 Jan 2005 Bruce Clark has submitted a new tutorial on Register Preservation that has been added to the Tutorials and Primers section. It shows common methods for preserving registers on the stack and also teaches how to properly distinguish whether an interrupt was caused by IRQ or the BRK instruction.
 
12 Dec 2004 Greg Cook's CRC Calculations have been added to the Source Code Repository. These routines execute in constant cycle time and do not require lookup tables.
 
30 Oct 2004 Jack Rubin has scanned five more issues of the magazine "MICRO: The 6502 Journal", issues 11 through 15, and they are now available for download.
 
31 Aug 2004 Jack Rubin has scanned the first year of the magazine "MICRO: The 6502 Journal". All six issues are available for download from the Documents Archive: /documents/publications/micro.
 
12 Jul 2004 Jonathyn Bet'nct has submitted two routines for comparing strings in Pascal format (length byte followed by string) that have been added to the Source Code Repository.
 
7 Jun 2004 Garth Wilson has written an excellent primer on programming interrupts that can be found in the Tutorials and Primers section. It introduces the concept of interrupts, demonstrates how to code interrupt handlers, explains special interrupt types (NMI, BRK, WAI), provides three sample projects that make good use of interrupts, and discusses performance considerations.
 
6 Jun 2004 The Datasheets Archive has moved. It can now be found here: /documents/datasheets/. In addition to having a new layout, all of the existing datasheets have now been converted to PDF format. A large number of additional datasheets have also been added, particularly from Rockwell and WDC.
 
31 May 2004 Andrew Dunn's SYMulator, a working SYM-1 simulator based on Daryl Rictor's 65C02 simulator, has been added to the SYM-1 section of the Microprocessors & Trainers area.

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.

 
26 May 2004 The Western Design Center has redesigned their website: http://www.westerndesigncenter.com
 
4 Apr 2004 Tony Gonzalez's address line test routine has been added to the General Purpose category of the Source Code Repository.

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

 
3 Apr 2004 Bruce Clark has made two excellent submissions. Practical Memory Move Routines can be found in the General Purpose category of the Source Code Repository. It presents several very useful routines for block memory moves. Beyond 8-bit Unsigned Comparisons is an extensive tutorial on signed and unsigned comparisons and it can now be found in the Tutorials and Primers section.
 
20 Mar 2004 Martin Arndt's Fast Multiplication routine, an algorithm that uses tables of squares to quickly multiply two numbers, has been added to the Source Code Repository.

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.

 
4 Feb 2004 Mats Rosengren's Optimal Sort, another improvement on the traditional bubble sort, has been added to the Source Code Repository.

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.

 
27 Jan 2004 Garth Wilson's routines for converting 8- and 16-bit hexadecimal numbers to their decimal (BCD) equivalents have been added to the Source Code Repository.
 
26 Jan 2004 Several broken KIM-1 links in the have been corrected or removed. Thanks to Dallas Shell for pointing these out.
 
25 Dec 2003 Sim65 - Sheldon Simms' 65C02 simulator and debugger for Linux/GTK systems, has been added to the list of emulators and simulators.
 
24 Oct 2003 Two missing binaries on the SYM-1 Page have been fixed. Thanks to Hans Otten for pointing this out.
 
20 Oct 2003 Alexis Kotlowy-Brown's ROMless 6502 Microcomputer has been added to 6502.org. Alexis has created a 6502 single board computer programmable only by DIP switches, built in the spirit of older microcomputers like the Altair 8800.
 
19 Oct 2003 A link to Rob Greene's Electronics Projects has been added to the Homebuilt Projects section. Rob's pages detail his experiments creating a VGA video subsystem for a 65C02-based SBC by using a PIC microcontroller.

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.

 
12 Oct 2003 Garth Wilson's Projects have been added to 6502.org. Garth has detailed several of his 6502-based projects and his pages contain many photographs and schematics.
 
12 Aug 2003 A link to the Index for Issues 0-14 was broken in the SYM-PHYSIS Newsletter Archive. Thanks to Mark Cummings for pointing this out.
 
26 Jan 2003 Keith Howell's Acorn Atom in an FPGA has been added to the Homebuilt Projects section. Keith's project uses an FPGA to implement the glue logic, a superset of the 6847 video controller, and a PS/2 keyboard interface.

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.

 
4 Jan 2003 The datasheet MOS Technology's 6562/6563 Video Interface Chip (VIC) has been added to the Datasheets Archive. Thanks to David Seiter and Cameron Kaiser for providing it.

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!

 
1 Dec 2002 A tutorial on the 6502's Compare Instructions has been added to the Tutorials section.

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.

 
28 Nov 2002 A FireCracker CM17A interface has been added to the Mini-Projects section. This project shows how to connect X-10's RF interface for the PC to a 6502-based machine for home automation projects.
 
21 Oct 2002 The Source Code Repository now includes a new submission from Garth Wilson, UM/MOD. These are routines for the unsigned division of a 32-bit dividend by a 16-bit divisor, resulting with a 16-bit quotient and a 16-bit remainder. Versions are presented for the 65C02 (with changes for use on the 6502) and 65C816, with notes of interest to Forth users.

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.

 
1 Oct 2002 SYM-PHYSIS Issue 11 is now available.
 
12 Sep 2002 David Wheeler has written some interesting material on 6502 Language Implementation Approaches that has been indexed in the Languages section of the cross-development area.
 
29 Aug 2002 A new forum (message board) has been set up on the 6502.org server! The 6502.org Users Forum will replace our old forum on DelphiForums. Please register yourself and start interacting with other 6502 enthusiasts. Since it's hosted right here on 6502.org, you won't be subjected to advertising or unwanted e-mail.
 
27 Aug 2002 Clearing a Section of Memory has been improved by Mickael Pointier and is now in the Source Code Repository.

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.

 
26Aug 2002 Lee Davison's pages have moved and are now linked correctly from the Homebuilt Projects section. Thanks to Gordon Zaft and Daryl Rictor for helping us keep the links up to date.

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

 
15 Apr 2002 Mike Genovy's 6502 pages have moved and the link has been updated.

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

 
27 Feb 2002 Mike Cowlishaw's Acorn Microcomputer Pages contain a large number of excellent pictures of a lesser-known European 6502 kit computer, along with history, documentation, and firmware for the device. This link has been added to the Simple Microcomputers and Trainers section.
 
21 Feb 2002 Delphi Forums has changed their URL. Our forum is still accessible at http://forums.delphiforums.com/6502. Please update your bookmarks and join in the discussions!
 
10 Oct 2001 A new section has been added to 6502.org called Supporting Materials. This area will hold any useful programs, circuits, or tools that may be of interest to the 6502 developer but are not specifically geared towards the 6502. The first entry in this new section is an EEPROM Programmer by Jay Kominek.
 
27 Sep 2001 Mike Genovy's 6502 Stuff has moved to a new location and the link in the Homebuilt Projects section has been updated.
 
20 Sep 2001 Special thanks to Wolfgang Guenther for helping us correct broken links in the SYM-1 and Datasheets Archive sections!

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.

 
31 Aug 2001 Simon Collis has developed a 6502 assembler called A6 which runs on DOS, Unix, and AmigaOS. A link to the program has been added to the Assemblers area of the Cross-Development pages.
 
5 Aug 2001 Lee Davison's Root Calculator has been added to the Source Code Repository.
 
5 Aug 2001 Phil Pemberton's 6502 Appreciation Group now has a mailing list on Yahoo! Groups, 6502AG. It has been added to a new section on 6502.org for Discussion Groups
 
5 Aug 2001 Micetek is a Taiwanese company which makes a product called EasyPack 6502F, an in-circuit-emulator (ICE) for the WDC W65C02. Their link has been added to the Commercial Support section.
 
5 Aug 2001 Christopher Cowen has a new webpage at CPC Microsystems which has been added to our Homebuilt Projects list. Chris' modular 6502 system, called the Jimini Platform, is expandable with cards on a backplane similar to VME and is programmed in C with CC65.
 
3 Jul 2001 Lee Davison has been hard at work on an excellent BASIC interpreter aimed at homebuilt systems. EhBASIC, or Enhanced 6502 BASIC, is a work in progress and includes many unique and powerful features. Check out what has been done so far and if you're interested in the project e-mail .
 
29 Jun 2001 Samir Lohani has created the Data Pod, a serial EEPROM storage device that provides nonvolatile storage to his 65C02 homebuilt computer. The DPOD has been added to the Hardware Mini-Projects section and includes photos, schematics, and a printed circuit board layout.
 
29 May 2001 Rich12345's Hardware Page has been added to the Homebuilt Projects on the Web page. It includes 6502-based hardware projects like Wozbot, the Apple II robot.
 
20 May 2001 Joachim Deboy has submitted a small multitasking kernel to the Source Code Repository.
 
18 May 2001 The Microlab kit is no longer being offered for sale and has been removed from the Commercial Support page.
 
17 May 2001 Daryl's Rictor's Combination Sort routine has been added to the Source Code Repository.
 
  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.
 
10 May 2001 Klaus Mussler's 6502 Single Board Computer has been indexed in Homebuilt 6502 Computers&Projects.
 
7 May 2001 Daryl Rictor's 65C02 Single Board Computer and 65C02 Emulator for Windows have been indexed in the Homebuilt 6502 Computers&Projects and Generic 6502 Emulation and Simulators sections, respectively.
 
6 May 2001 The links to the Western Design Center datasheets have been fixed and they are once again available for download from the Datasheets Archive.
 
23 Apr 2001 California Micro Devices (CMD) G65SC21 Full Datasheets (PDF) are now available for download from the Datasheets Archive.
 
22 Apr 2001 Issue #10 of SYM-PHYSIS magazine has been added to the SYM-PHYSIS archive.
 
17 Apr 2001 Michal Kowalski has written an excellent program for Windows called the 6502 Macroassembler and Simulator. It is an integrated development environment which allows an assembly language program to be written, assembled, and simulated. The author is actively developing and continually improving the program. A link to it has been added to the Generic 6502 Emulators and Simulators page.
 
16 Apr 2001 Ross Archer and Lee Davison were rather unimpressed with Commodore's implementation of the PRIMM routine. They have both submitted improved versions which have been added to the Print Immediate (PRIMM) routine page.
 
30 Mar 2001 John Pickens' 6502 Opcodes information page added to Tutorials and Aids.
30 Mar 2001 A Tutorials and Aids section has been added.
28 Mar 2001 Print Immediate (PRIMM) added to Source Code Repository.
27 Mar 2001 Lee Davison's PC/AT Keyboard Interface added to Hardware Mini-Projects.
22 Mar 2001 Ross Archer's Intel HEX File Downloader added to Source Code Repository.
10 Mar 2001 Added News and Updates page.