by Steven B. Combs, Ph.D. tags: commodore - mega65 - firmware - rom - core - m65connect
Updating the MEGA65 requires several steps that can confuse new owners (count me in that group!). This blog post and associated FAST LOAD video will demonstrate the process and serve as a reference to update a MEGA’s SD card essential files,
MEGA65.ROM, core (bitstream), and the M65Connect software. Before reading the rest of the post, I recommend you watch the retroCombs FAST LOAD video. You will find it after the table of contents below.
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Table of Contents
In the video below, I demonstrate the process to update the MEGA65 (Dev Kit), core, SD card essential files,
MEGA65.ROM, and M65Connect software.
MEGA65 ownership (especially the Dev Kit), means continual updates full of fixes, compatibility enhancements, and new features. Luckily, there’s a community on developers devoted to these updates. In their free time, they even help non-developers like me.
I reached out to atdbm (@adtbm#1347) and asked, “What’s the priority for updates, the
MEGA65.ROM or the CORE.” Below is the answer used to guide the flow of my update process. He wrote (not a direct quote and modified):
- Always use the latest SD card essential files
- Choose a bitstream that works for you, (I use the latest version after confirming that all standard functions work)
- ROM, chose either 911210 (latest as of this writing) or the latest MEGA65 ROM by BitShifter (I use Bitshifter’s ROMs because they are super fast and clean)
Let’s get started!
This step assumes you have an SD card formatted. If you do not, check out the BONUS: Format an SD card in the MEGA65 section below. The first step is to update the SD card “essential” files listed below:
MEGA65.ROM(Not included in download)
WARNING: If you have .d81 or .d64 files (other files) on the SD card, this process won’t overwrite them; however, I recommend you make a backup.
.rarand operating systems (OSs) usually include the ability to extract these files.
Copy/Move the extracted files to the SD card.
NOTE While it is not necessary to reformat the SD card to update the MEGA65, I do include the instructions in the BONUS: Format an SD card in the MEGA65 section below in case you have a brand new SD card.
If you have the latest
MEGA65.ROM file on the SD card, your update is complete. If you need to update the
.ROM file, continue to the next section.
Download the latest MEGA65 SD Kernal ROM. The file will have a
NOTE: The link above works for MEGA65 FILE HOST account holders who own hardware. An Open ROM for MEGA65 is available for XEMU emulator users.
MEGA65.ROMon your SD card to the previous version number (for example:
MEGA65-3-6.ROM). This will archive the previous
.ROMin case the new one doesn’t function properly.
920124.BINas of this writing) file to
MEGA65.ROMfile to the root directory of the MEGA65 SD card along with the other essential files.
With the essentials file on the SD card updated, you can now explore the new features and upgrades; however, there is one more thing to do; update the hardware, via a bitstream (core), as I demonstrate in the next section.
Use the Search tool in the upper-right corner to search for the bot, Jenkins. These posts will contain a link to the latest version of the cores in
.mcs file formats.
NOTE: In the future, MEGA65 cores will come in
.corfile format. For now, we convert
.mcsfiles and transfer the core via M65Connect or copy it directly to the SD card (my preferred).
In the main menu, select File / Create COR File. The Create COR file dialog box will appear as shown below:
.bitfile, you downloaded in step #3.
.corfile in the same directory as the original
.corfile to the root directory of a MEGA65 formatted SD card that contains all essential files.
Hold the No Scroll button and turn on the MEGA65. The cores utility screen will appear as shown below.
NOTE: THE MEGA65 supports eight cores. Core 0 is reserved and will always contain a default MEGA65 core that is hard, by design, to change. This ensures a working core is always available.
Select an empty core, or a core to replace using
CTRL + the core number (1→7). The screen border will flicker and the core selection screen, listing new cores found on the SD card, will appear as shown in the image below:
↓ keys to move through the list, select the core to flash, and hit
⏎. The MEGA65 will first erase the core in the flash slot (if there is one), install the new core/bitstream, and then verify the core/bitstream. When complete, the MEGA will indicate, Flash slot successfully written. Press any key to return to menu.
NOTE: This is not a fast process and can take up to 20 minutes if a core needs to be erased first. Luckily, the MEGA65 includes a progress bar.
⏎and the core menu will appear again.
↓to move to the new core item in the menu and press
⏎. The MEGA65 will restart with the new core and use flag this core as the default core until you load the core menu and select another core. That’s a lot of core!
As mentioned, you have seven usable cores. You can use them to test various MEGA65 cores, or in the future, there will be new cores for more computers such as Atari and Amiga computers. As of this writing, you can install a ZX Spectrum core, the ZX-Uno!
While not required to update the MEGA65, go ahead and check on a M65Connect update. The latest version (1.2 as of this writing) of the M65Connect software is available to anyone on the MEGA65 File host or you can click the links in the instructions below for specific operating systems versions:
The link’s page lists the current version number to compare with the currently installed version. Once downloaded, install the M65Connect software following your operating systems process. I don’t cover the features of M65Connect in this blog post. If you are interested, drop a comment below and let me know.
Remove all cards from the MEGA65 except the one you intend to format. This will ensure you don’t accidentally format a working SD card.
NOTE: The internal SD card is on bus 1, and the external card is on bus 0. The MEGA65 will always attempt to boot the external, bus 0, SD card first.
While holding down the [ALT] key, power-on the MEGA65 and the MEGA65 Hypervisor Menu will appear as shown in the image below:
Select SDCARD FDISK+FORMAT UTILITY from the menu and the screen below will appear and then poll each SD card reader to determine if and what size card is attached.
⏎. The MEGA65 will format the SD card.
When the process is complete, you will need to either copy an archive of your essential files, or follow the steps beginning in the Update the SD Card section.
Those are the steps for keeping the MEGA65 (DevKit) updated and I hope these will be the same steps for the product’s final release. If not, no fear. I’ll update this post with the most up-to-date process. When and if I do update, you will find
strikethroughs and timestamps.
Since these procedures are not something I do everyday, I’m sure I will come back to this post the next time I need to upgrade my MEGA65. Hopefully, you will too! Let me know in the comments below, or under the video, if there’s something missing or I could explain with better clarity. Enjoy the MEGA65 folks! I know I am.
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