CERBERUS 2100™

The software-rewireable, educational, multi-CPU, BASIC-programmable microcomputer with powerful, generic expansion capabilities! CERBERUS 2100™ is the successor of <a href="https://github.com/TheByteAttic/CERBERUS2080">CERBERUS 2080™</a>, which is now obsolete. Check out the project's <a href="https://www.thebyteattic.com/p/cerberus-2100.html">official homepage</a>. <br><br> <b><i>BREAKING:</i></b> <a href="https://www.olimex.com/Products/Retro-Computers/CERBERUS2100/open-source-hardware">Olimex is now selling ready-to-use CERBERUS 2100™ units!</a> <br>

CERBERUS 2100™ is an educational multi-processor 8-bit computer, featuring both Z80 and 6502 CPUs, plus an AVR processor as I/O controller. Built with CPLDs, CERBERUS 2100™ is fully programmable even with respect to its hardware, at the level of individual gates and flip-flops. It runs BASIC interpreters for both CPUs, but can also be used in a 'bare metal' mode through its built-in BIOS. It can even be extended through its expansion slot, which comes paired with a powerful, generic communications protocol that allows for Direct Memory Access (DMA). A detailed description of CERBERUS 2100™ is available in the <a href="https://github.com/TheByteAttic/CERBERUS2100/blob/main/CERBERUS%202100%20Hardware%20Manual.pdf">Hardware Manual</a>. And for the latest technical developments, you can join the <a href="https://www.facebook.com/groups/cerberuscomputer">developers' group</a>.<br><br> CERBERUS 2100™ is a collaboration of three developers: Alexander Sharikhin (<a href="https://github.com/nihirash/cerberus-w65c02s-basic">6502 BASIC interpreter</a>, BIOS optimizations, and test code optimizations), Dean Belfield (<a href="https://github.com/breakintoprogram/cerberus-bbc-basic">Z80 BASIC interpreter</a> and BIOS optimizations), and myself (hardware, original test code, and original BIOS code). The <a href="https://github.com/TheByteAttic/CERBERUS2100/blob/main/CERBERUS%202100%20Hardware%20Manual.pdf">Hardware Manual</a> does not document the software, so you should visit <a href="https://github.com/nihirash/cerberus-w65c02s-basic">Alexander's</a> and <a href="https://github.com/breakintoprogram/cerberus-bbc-basic">Dean's</a> repositories for that.<br><br> The applications in the directory <a href="https://github.com/TheByteAttic/CERBERUS2100/tree/main/Cerberus%20uSD%20card%20files">Cerberus uSD card files/</a> contain code from Alexander and Dean, but also software developed by others, namely: a <a href="https://github.com/lennart-benschop/cerberus-z80-forth">FORTH interpreter for CERBERUS 2100's Z80 CPU</a>, ported by Lennart Benschop, and the <a href="https://github.com/envenomator/cerberus2080-sokoban">SOKOBAN game ported to CERBERUS 2100's 6502 CPU</a>, by Jeroen Venema.<br><br> CERBERUS 2100's BIOS code uses a modified version of the <a href="https://github.com/PaulStoffregen/PS2Keyboard">Arduino PS/2 Keyboard Library by Paul Stoffregen</a>, which we gratefully acknowledge.<br><br> The directories in this repository are as follows:

<UL> <LI><a href="https://github.com/TheByteAttic/CERBERUS2100/tree/main/CAT">CAT</a>: contains the BIOS code for FAT-CAT, CERBERUS 2100's I/O controller. This code is simply an Arduino sketch written in C and resides in FAT-CAT's on-board flash memory.</LI> <LI><a href="https://github.com/TheByteAttic/CERBERUS2100/tree/main/CERBERUS%20Applications%20Source%20Code">CERBERUS Applications Source Code</a>: contains the assembly source codes of four test programs, which illustrate how assembly code can be written for CERBERUS 2100™, including communication between CPU and I/O processor.</LI> <LI><a href="https://github.com/TheByteAttic/CERBERUS2100/tree/main/CPLD_Files">CPLD_Files</a>: contains the design and JEDEC files for the three CPLDs used in CERBERUS 2100™ as its custom chipset.</LI> <LI><a href="https://github.com/TheByteAttic/CERBERUS2100/tree/main/Cerberus%20uSD%20card%20files">Cerberus uSD card files</a>: contains the files users should copy to a class-10 (or higher), FAT32-formatted micro SD card to be inserted in CERBERUS 2100™ prior to starting it up. The files contain the character set definitions, both BASIC interpreters, BASIC programs, test code, and other applications.</LI> <LI><a href="https://github.com/TheByteAttic/CERBERUS2100/tree/main/Design">Design</a>: contains the design files of the CERBERUS 2100™ board, including schematics and PCB design files.</LI> <LI><a href="https://github.com/TheByteAttic/CERBERUS2100/tree/main/Manufacturing">Manufacturing</a>: contains the files needed to have CERBERUS 2100™ boards made by your favorite PCB manufacturer. The files include the Gerber set, Bill of Materials, and Pick & Place (a.k.a. centroid) specifications.</LI> <LI><a href="https://github.com/TheByteAttic/CERBERUS2100/tree/main/Photos">Photos</a>: contains high-resolution, properly illuminated photos of a correctly assembled CERBERUS 2100™ unit. These photos can be used as reference for manual assembly, or to illustrate articles on CERBERUS 2100™. If you are a journalist, member of the media, or tech blogger, please feel free to use these photos without need to request explicit authorization from me.</LI> </UL> <br> Copyright © 2023-2024 by Bernardo Kastrup. All rights reserved. Provided under <a href="https://github.com/TheByteAttic/CERBERUS2100/blob/main/LICENSE">license</a>. <br> <hr> <b>CHANGE HISTORY:</b><br><br> <UL> <LI><b>26 March 2024:</b> Small change to the BIOS code so to avoid the possibility of an annoying beep upon software reset.</LI> <LI><b>25 March 2024:</b> Alexander Sharikhin has updated his BASIC interpreter and demo code (basic65.bin, c1.src, c2.src, and c3.src in the <a href="https://github.com/TheByteAttic/CERBERUS2100/tree/main/Cerberus%20uSD%20card%20files">/Cerberus uSD card files</a> folder) to take into account the new color capabilities of the system. He has also created a <a href="https://github.com/nihirash/cerberus-w65c02s-basic/blob/main/Quick%20start%20manual.pdf">manual for the CERBERUS 6502 BASIC interpreter</a>. <LI><b>05 March 2024:</b> New startup screen options by <i>Movie Vertigo</i> have been added to the folder <a href="https://github.com/TheByteAttic/CERBERUS2100/tree/main/Cerberus%20uSD%20card%20files/AlternativeBootScreens">/Cerberus uSD card files/AlternativeBootScreens</a>. These change the character definitions and may have side effects in earlier software. To solve the latter, just reload the default character definitions file.</LI> <LI><b>18 February 2024:</b> Several applications by Lennart Benschop, in the <i>/Cerberus uSD card files</i> folder, have been updated to take advantage of CERBERUS's new color capabilities (see update from 28 January 2024 below).</LI> <LI><b>8 February 2024:</b> The game Sokoban, by Jeroen Venema, in the <i>/Cerberus uSD card files</i> folder, has been updated to take advantage of CERBERUS's new color capabilities (see update from 28 January 2024 below).</LI> <LI><b>3 February 2024:</b> Update to the firmware (faster reads and writes by FAT CAT) through a pull request from Jeroen Venema.</LI> <LI><b>28 January 2024:</b> FAT-SCUNK (files FAT-SCUNK.PLD, FAT-SCUNK.fit and FAT-SCUNK.jed in the <a href="https://github.com/TheByteAttic/CERBERUS2100/tree/main/CPLD_Files">/CPLD_Files</a> directory) has been updated so to display up to 8 colors simultaneously on the screen. Specific foreground colors are assigned to specific character codes (not screen positions). The <a href="https://github.com/TheByteAttic/CERBERUS2100/blob/main/CERBERUS%202100%20Hardware%20Manual.pdf">Hardware Manual</a> has been updated accordingly, including the video architecture diagram on page 14. See page 19 for more details. <i>These changes are unrelated to the PCB, BoM and centroid files, and even the firmware;</i> they are accomplished simply by reprogramming one of the CPLDs, and can be applied to all existing boards.</LI> <LI><b>30 August 2023:</b> Correction to the BIOS code (affecting expansion port control), as pull request from Jeroen Venema.</LI> <LI><b>28 August 2023:</b> Minor typo corrected on page 49 of the Hardware Manual.</LI> <LI><b>26 July 2023:</b> Corrections and extensions to the Hardware Manual.</LI> <LI><b>26 July 2023:</b> Full initial commit.</LI> </UL>