• Commodore
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  CBM PETindex
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  CBM hardware and mods
• Hardware
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  The 65k Project
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  CS/A65 Caspaer and Gecko computer
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  Advanced 6502
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  ICs and Standards Info
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  Other hardware (e.g. tools)
• Software
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  GeckOS operating system
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  Lib6502 standard
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  O65 file format
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  Misc software
• Knowledge Bits
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  Computer/OS Architecture
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  6502 Hardware Bits
• Misc
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  Contact
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  Sneak preview
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  Web design

Discuss my site on this 6502.org forum thread

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Dive into the retro feeling and build yourself a Commodore PET replica

Need more speed? Speed up your 6502 computer with this 10 MHz 6502 CPU replacement board

Interested in electronics design? Look at the design lesson I got from Bil Herd, the hardware designer of the C128

Want 64bit? - pimp the 6502 with the 65k processor design!

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  2011-01-02 Some small updates to the 65k programming specs. Moved some opcodes around to achieve a more regular mapping
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  2011-01-02 Updated the CS/A Ramdisk board. Now a CPLD-based version is available in addition to the older TTL-based version.
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  2010-12-28/2010-12-22 Minor update to the 65k programming specs - added the "NF" prefix bit. Moved some LSB $f opcodes to ext page to add "abs,Y" addressing mode opcodes.
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  2010-12-22 Updated the CPU816 board (v2) to fix the ROM programming, and make it compatible with the PET816 board.
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  2010-12-20 Reorganized the CRTC pages.
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  2010-10-23 It took a while, but now I published the first draft of my 65k processor design - Pimp your 6502 with 64 bit! :-)
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  2010-09-12 Some more web design updates. Using web sprites, css and javascript compression should result in better load performance. Total files for this start page goes from 23 down to 9, the total size to load goes from 182k down to 150k.
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  2010-09-05 I managed to use my 65816 board successfully in a PET4032, even use it for debugging the hardware problems of the 4032
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  2010-08-29 I have added some experience and sample measurements with my new oscilloscope on the oscilloscope bits page.
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  2010-08-28 Again (and again :-) I have updated the PET 65816 board, to speed up the PET to 10MHz by replacing the 6502 with a 65816 card. As far as I am concerned, this version now works as much as I can test it! The page now also contains in-depth explanations of the features and how it works!
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  2010-08-22 Again I have updated the PET 65816 board, to speed up the PET to 10MHz by replacing the 6502 with a 65816 card.
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  2010-08-22 Improved the CS/A VDC and CPU boards with better layout and a bug fixed.
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  2010-08-11 I have updated the PET 65816 board, to speed up the PET to 8MHz by replacing the 6502 with a 65816 card.
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  2010-08-02 Improved the CS/A BIOS and CPU boards with better timing.
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  2010-06-06 Major web design update. New (menu) icons, new stylesheet with a new 3-column layout, and a much more functional menu. The menu is now dynamic, and allows filtering it for keywords. I hope you like it. Caveat emptor: I have tested with a number of browsers and system but not everything is perfect yet. Let me know if you find anything annoying.
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  2010-05-31 Added a Sneak Preview page with my 8-bit plans...
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  2010-05-11 Added some links and updates to the PETindex page
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  2010-05-11 Added a patched PET BASIC4 kernal ROM to enable the CS/A PET replica to run at 2MHz
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  2010-04-21 Updated the page for the Xilinx tools with information about VHDL simulation tools I use.
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  2010-04-20 I have added a PET 65816 board, to speed up the PET to 10MHz!
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  2010-04-12 Added a new error pattern for the PET repairs page.
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  2010-04-11 Added a page for the Xilinx tools I am using for my newest designs
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  2010-04-11 Updated the PET extensions page.
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  2010-04-11 I finally made my first CPLD design work. See the CSA 65816 CPU page.
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  2010-01-12 During the developement of my RAMDisk board I had a very good discussion with Bil Herd, the principal design er of the Commodore Plus/4, C16/C116, and the much more successful Commodore 128, in which I learned a lot about hardware design in a mass production setup. Here is a summary of our discussion about the use of DRAM and schematics and board design in general.
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  2010-01-06 Added a PET extension page, as well as a page for the PET harddisks to the PETindex. Fix an error in the keyboard matrix shown on the keyboard page. Improve layout of some PETindex pages.
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  2010-01-04,2010-01-06 Add block diagram and memory map for 65816 CS/A board. Added V1.2B of the power supply board. Added a (partially working) RAMdisk board using old 30pin SIMM dRAM modules.
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  2010-01-03, 2010-01-07 Fixed a number of links all over the place. Separated the knowledge bits section into two subsections.
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  2010-01-01 Finally here it is! I managed to build the 65816 CPU board for the CS/A65. The CPU runs at 8 MHz and makes a PET real fast :-)
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  2009-12-13 A bit late, but actually in october 2009 the CS/A65 had its 20th anniversary! I had hoped to have a 65816 CPU board ready that I have in the making, but I am still working out some timing issues. Stay tuned!
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  2007-06-29 The Video board page has helper circuits to convert the output to composite video.
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  2007-06-27 A new version of the Gecko board, including a PET ROM version using an RS232 interface as editor.
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  2007-06-07 A new SPI page for the CS/A computer, with a schematics and driver to handle MMC and SD-Cards.
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  2007-05-28 The new Miscellaneous Hardware page has a logic probe.
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  2007-05-26 The CS/A65 computer now has a power supply adapter for PC power supplies, and a VIA prototyping board.
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  2007-01-12 Added a page with PET repair information.
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  2007-01-03 Added an Auxiliary CS/A65 CPU board, that can handle bus error conditions on the main cpu bus, as well as an article on the hardware aspects of multitasking and multiprocessing explaining the reasoning behind the board.
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  2006-12-21 Added a prototype PET CS/A65 adapter board, so that PETs can use CS/A65 boards as well. Also added an old article about the GeckOS operating system.
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  2006-12-16 Finally! Added a new CSA coprocessor board, that allows simultanous multiprocessing :-) Also added a new C64 adapter to use CS/A boards.
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  2006-12-14 Added a new CSA SCSI board, that now includes an I2C controller, and also a test driver for the PETCPU RS232 interface and confirmation that this interface works.
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  2006-11-26 Added a section to build your own, new, Commodore VC1581 using a PETCPU and DRVIO CS/A65 board.
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  2006-11-24 Updated the CS/A computer with a memory map, also added a new I/O board for PC floppies and serial IEC bus. Also added tables with jumper settings for the PETCPU board.
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  2006-11-21 Better graphical look-and-feel by using nicer icons. Also overhauled layout of the CRTC info pages and actually linked the CRTC raster effects test programs. Additionally I have added more information about the PET 8032 and 8296 use of the CRTC to the PETindex CRTC page.
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  2006-11-20 Updated the PETindex to version 1.1 by adding more information on the SuperPET and 8x96 boards.
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  2006-11-12 I have added ROMs and jumper settings to the Roll-you-own-PET page.
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  2006-11-12 There are three new articles in the Knowledge bits sections. One article explains virtual address spaces and how to implement them with a 6502, one describes the use of a UART chip for an RS232 interface with a 6502, and the third article explains an infrared remote control using a VIA 6522.
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  2006-11-01 I have added the article page with for now one article how to generate the RDY signal for a slow device.
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  2006-11-01 I have added a few items, like the MMU replacement board, or the Roll-you-own-PET page where you can build your own PET 4032.
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  2006-11-01 For some of the CS/A65 boards I have added the driver code as extracted from the GeckOS operating system.
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  2006-11-01 The CS/A65 part has been completely overhauled, and some boards have been updated and new boards have been added!
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  2006-11-01 Completely overworked the 8-bit pages. Now includes a navigation menu and is better maintainable (for me :-). I have also streamlined the webpage hierarchy. I hope you like it!
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  2006-08-07 I have updated the links from funet to the new home of the Commodore archive at http://www.zimmers.net/anonftp/pub/cbm/, as well as checked the other links and updated them where necessary.
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  15jun2000 Some of those pages have been rewritten into XML that is transformed into HTML by using an XSL transformation.