André 's 8-bit pages

On these pages you will find quite some information concerning selfbuilt 8-bit computers of the 6502 line. Also some stuff for old Commodore machines with this CPU is there, like new C64 kernals, VC1541 modifications etc. A selfbuilt operating system features Multitasking, dynamic memory management, a standard library and internet access.

In the works...

These are the things I currently have in the works - although actually in the works for about two years now...

A board with an Ethernet and two USB connections. I have the board and the parts, but I think I still need to get more up to date with SMD soldering...
I plan to update the GeckOS operating system to improve messaging and communication throughput, add C support and more. This is currently planned only.
A "Blitter" board - to transfer bulk data from one memory location to another - planned.

News:

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.
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 :-)
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.
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.
2010-01-03, 2010-01-07 Fixed a number of links all over the place. Separated the knowledge bits section into two subsections.
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!

Quickfinder

Commodore 8-bit stuff
- PETindex - a list of hardware information and links to the old CBM PET machines
- Commodore Hardware mods and projects : Various CBM hardware projects, like SCSI interface, or a project to build Your own new PET 4032. Other items are C64 kernel mods and IEEE488 interfaces, including one for the PC to use it as disk drive.

General 6502 hardware stuff
- CS/A65 and Gecko are my selfdesigned and selfbuilt multi- resp. singleboard 6502 computers. The CS/A65 features virtual memory, video card, a SCSI interface and many more stuff I have now linked my CS/A65 emulator, based on the VICE emulator, to this page.
- Hardware info : Information on various items and standards used in these pages. Examples are CRTC and 74ls610 MMU info, and information about the SCSI and I2C standards.
- Hardware Tools and Stuff : Miscellaneous hardware stuff. Currently contains a Logic Probe.

6502 software stuff
- GeckOS/A65 A small 6502 multitasking operating system that runs on the Commodore C64 and PET computers, as well as my selfbuilt 6502s.
- LIB6502 is an attempt in defining a C-like standard library for 6502 assemblers. It is used in GeckOS/A65.
- o65 fileformat is a flexible relocatable 6502/65816 fileformat.
- Software I wrote with relation to the 6502. Features cross assembler, C64 basic extension, etc.

6502 knowledge bits
- Articles I wrote about computer system and operating system architecture with relation to the 6502. Currently contains a articles about 6502 multiasking, Use of an MMU with the 6502, and about the GeckOS/A65 multitasking operating system.
- 6502 hardware related articles I wrote. Articles are about hardware like RDY generation, using a UART in a 6502 system, or how to create an infrared remote control. Also has a discussion with - or rather a design lesson I got from - Bil Herd, the hardware designer of the Commodore 128.

Old News:

2007-06-29 The Video board page has helper circuits to convert the output to composite video.
2007-06-27 A new version of the Gecko board, including a PET ROM version using an RS232 interface as editor.
2007-06-07 A new SPI page for the CS/A computer, with a schematics and driver to handle MMC and SD-Cards.
2007-05-28 The new Miscellaneous Hardware page has a logic probe.
2007-05-26 The CS/A65 computer now has a power supply adapter for PC power supplies, and a VIA prototyping board.
2007-01-12 Added a page with PET repair information.
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.
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.
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.
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.
2006-11-26 Added a section to build your own, new, Commodore VC1581 using a PETCPU and DRVIO CS/A65 board.
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.
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.
2006-11-20 Updated the PETindex to version 1.1 by adding more information on the SuperPET and 8x96 boards.
2006-11-12 I have added ROMs and jumper settings to the Roll-you-own-PET page.
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.
2006-11-01 I have added the article page with for now one article how to generate the RDY signal for a slow device.
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.
2006-11-01 For some of the CS/A65 boards I have added the driver code as extracted from the GeckOS operating system.
2006-11-01 The CS/A65 part has been completely overhauled, and some boards have been updated and new boards have been added!
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!
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.
15jun2000 Some of those pages have been rewritten into XML that is transformed into HTML by using an XSL transformation.

Disclaimer

All Copyrights are acknowledged. The information here is provided under the terms of the GNU Public License version 2 unless noted otherwise.

Last updated 2010-01-07.