Author Archives: Obliterator918

Pi1541: a cycle-exact 1541 emulator for Raspberry Pi

Steve White has developed a wonderful application for a Raspberry Pi 3: Pi1541

Pi1541 is a cycle-exact emulator for the 1541 disk drive. Have a look-see. If you want to try this out, you’ll need some soldering skills to make the cable that attaches the C64 IEC bus to the Pi’s GPIO.

If you’ve already got Gideon’s 1541 Ultimate, there’s not much call for the Pi1541, but a Pi costs you less and you might have fun with the DIY aspect of putting it together. (The 1541 Ultimate still can’t be beat, especially considering the freezer functions you get with it.)

Also, I haven’t tried the Pi1541 yet, but I suspect the SD2IEC output  from GB Organizer would work well with it. Steve’s Pi1541 seems to work much like an SD2IEC on the computer-side.

Here’s one of Steve’s videos on the project:

Galactic Rasterbar Power

Today I am releasing a new C64 Demo: Galactic Rasterbar Power.

PRG file: Galactic Rasterbar Power.prg
Music only: Phosphor Advance.sid

screen shot

Galactic Rasterbar Power screen shot

I coded this demo in my spare time to accomplish a few goals:

  • Broaden my understanding of 6502/6510 assembly and the C64 memory map
  • Learn more about the VIC-II and how it works along with the CPU
  • Create some interesting multicolor bitmap graphics for my C64
  • Master the raster bar demo effect that I have always really enjoyed
    • And by extension, understand and implement cycle-exact code
  • Make a demo that works equally well on PAL and NTSC hardware.
  • Write some music for the SID chip, and make it work on both major revisions of the SID
  • As a bonus: make the raster bar effect look absolutely perfect in VICE debug borders.

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Why doesn’t GameBase64 Reorganizer include Extras?

Two reasons:

  1. When I originally wrote the Reorganizer, I had no interest at all in including the GB64 Extras. My goal was to keep the emitted archive as reasonably small as possible, and including a bunch of stuff I didn’t need wasn’t in keeping with that goal.  I didn’t even explore the possibility to including extras at that time.
  2. Now that the 1541 Ultimate has grown in capability and storage space is approaching “free,” I would actually like to include the Extras. For my European retroheads who really like their tapes, it would be nice for them to be able to play the original TAP files from their 1541 Ultimate, and I like the idea of being able to mount-and-run a .crt from a game, too. However, including these files is problematic because:
    • GameBase 64 Reorganizer uses the NFO files in each .zip file to figure out the name of the entry and the linked sid file. Without the NFO files, Reorganizer can’t do anything useful.
    • GameBase 64 doesn’t include any of the Extras information in the NFO files. This information is only included in the actual Microsoft Access database file that lies at the heart of GameBase 64. There is no pattern of file naming in the Extras folders that would make it clear which extras go with which entries– they are manually linked when the database is edited by its curators.

How could I work around this?

Essentially, I would also need to have Reorganizer open and analyze the Microsoft Access database file that GameBase 64 uses. This wouldn’t be all that difficult, but it does mean a lot of new code in Reorganizer and some significant retrofitting to its scanning engine.  Will I ever do this? Maybe at some point. But no time real soon.

Alternatively, the GameBase 64 team could opt to start including linked extras in the NFO files, just like they include links to the game sids in the NFO files. That would make this considerably easier, but I do not know if that is in keeping with their goals in curating the collection.

Why post this?

Because people have asked me to include Extras, and this is an easy answer to point them to. That’s all.

GameBase 64 Reorganizer released

A minor update to Gamebase 64 Reorganizer has been uploaded. The new version is

In previous versions, the program would fail to extract the archives if there were 251 or more items in the Z folder. The most archives present in the Z folder up through GB v14 was less than 250, so nobody ever came across this until some recent testing and made me aware of it. It was a simple bugfix. Upgrading to this version is strongly recommended. You can download the new version or read the full changelog here.

Compatibility status of Gamebase Reorganizer SD

Nothing major here, just a post confirming that (as far as my testing shows) GB Reorganizer SD works correctly with Gamebase v14 and runs properly on Windows 10. I have not bothered to update the documentation in Reorganizer to reflect this information but wanted to post it somewhere.

I do not test in virtual setups that don’t use Windows drive volumes so I can’t comment on compatibility with something other than NTFS or ReFS file systems and Windows emulators or VMs.


GameBase 64 Reorganizer SD version 4 released

GB Reorganizer has had quite an update today. I’ve posted version 4.0 with some important improvements and fixes. Don’t know what this is? Read about it here.

Someone pointed out to me that the Reorganizer was creating empty (no disk) output on archives with .TAP or .G64 images in them. Well, when I originally coded this utility for use with my 1541 Ultimate, the only image formats supported were .T64 and .D64. But that has changed and GameBase 64 is now using quite a few different image formats — .TAP, .T64, .G64, .D81, as well as the ubiquitous .D64. So now these are all recognized and extracted. (Whether or not your chosen device will support the images is a different matter — my 1541-U Mark 1 unit, with my custom firmware, can handle .D64, .G64, .CRT, and .T64 images, but not .TAP or .D81.) Still, it is better to include the files in the output for possible future support by your device.

Another important change for 1541-U users is how filename case is handled. Again, way back in the days of pre-2.0 1541-U firmware, the sorting and searching in the file browser were all case-sensitive, so it was necessary to upper-case all of the output for more useful browsing behavior. Somewhere along the line Gideon fixed all of the sorting and searching to be case-insensitive so this is no longer necessary. But if you are using a really old firmware, such as what was flashed in the old mark-1 units, you will want to restore the previous behavior with the “Ancient 1541-U Uppercase Mode” option. Or better yet, use my custom firmware so you don’t need to. (1541 Ultimate II users shouldn’t need to worry about it.)

I’ve also added a way to save and load your settings. This makes it easier to deal with different output configurations you want to have.

There’s a test mode now, too, which writes out the GameList.csv file but doesn’t build the folder structure or extract the archives.

There are some other changes. Download it here. sd2iec device users shouldn’t feel left out. There are bug fixes in here that affect output for the sd2iec optimized folders as well, so everybody should upgrade.

  • Improved GameList.csv output includes error messages on each folder/game (if any).
  • Recognize and extract .D81, .CRT, .G64, and .TAP files from archives (in addition to .D64 and .T64 files).
  • Change 1541-U folder name case to be mixed instead of forced upper-case. Added “Ancient 1541-U Uppercase Mode” for 1541-U file optimization (uses the previous behavior for file case naming). Use this option if you prefer the old way or if you have a really old firmware and you need it for proper sorting/searching on the 1541-U.
  • Added Test Mode. THIS STILL DELETES ANY PREVIOUS REORGANIZER OUTPUT IN THE DESTINATION FOLDER. This mode does everything except create the folders and extract the files, and you can review the GameList.csv file for results.
  • Added Load/Save Settings function.
  • Some cosmetic changes such as an improved icon design and changes to the faux-C64 status screen, just because.

Commodore: The Amiga Years appears to be back on track!

A few years ago, Brian Bagnall, author of On the Edge: The Spectacular Rise and Fall of Commodore, and Commodore: a Company on the Edge announced that his followup book, Commodore: The Amiga Years was officially cancelled.

Now it seems to be back on.  I was not able to find any official word from Bagnall, either at his publishing website or on his Twitter account, but Amazon is showing The Amiga Years to be scheduled for release in November of 2015.

Get your pre-order in. 🙂 UPDATE June 7, 2015: Looks like Brian has announced a Kickstarter to get this published. It was listed for pre-order on Amazon before that announcement, and if you made a pre-order you may want to see if any of the perks make it worthwhile to cancel and fund the campaign instead.

If you don’t know: The original book, On the Edge, is a single volume history of Commodore which goes all the way to 1994. This is an excellent book and well worth a read, though now out of print.

Bagnall had so much information that he could not squeeze into a single volume that he decided to release a new two-volume history of Commodore. He published Commodore: a Company on the Edge which, essentially, is the first half of On The Edge but much expanded. This is also a great read and should be in your library if you are a computer history buff.

But things did not go well for the second volume (The Amiga Years) and for a long time it looked like we would never see it. But now it looks like we will finally get the “long version” of the definitive history of the fall of Commodore.

Bagnall’s history is great. He sets the record straight about what really happened with Apple and Commodore, showing conclusively that a lot of the “revisionist history” proffered by Apple fans is a lot of nonsense. The reality is that Commodore did more to introduce computing “to the masses” than any other company during its time, and Bagnall’s research and writing does an excellent job reminding us what was going on, and what was so special about Commodore.