Allround Amiga music player "HippoPlayer" got a new update, with lots of fixes and enhancements.
It updates HippoPlayer to version 2.52, thus requires an existing full installation.
Here's a quick overview of the changes from 2.50 to 2.52 (skips 2.51), according to the AmiNet readme file (see link below):
Go to AmiNet for full details and download:
http://aminet.net/package/mus/play/hippoplayerupdate
The Sinclair ZX81 is a wonderful little machine. It's limitations create both a simple, fun environment to play with, and a challenge for developers.
About four decades ago, I started learning about computers with a ZX81. Type in stuff on a minimalist keyboard, print characters to a simple 32x24 characters monochrome screen, don't worry about colors or sound, because they're just not there. The ZX81 has very little memory, and the user interface is almost non-existent, so you're done pretty quickly. It's great, but also very limited in terms of sophisticated tools - there's just no extra room for such things, and you're having a hard time entering and editing the required data on the ZX81 anyway.
About three decades ago, I started using an Amiga. The Amiga, in comparison to the ZX81, is a highly capable computer. It has plenty of room, tons of screen size, a proper keyboard, several standard I/O ports, and colors and sound on top of it. Well, obviously it became my main computing platform.
About two weeks ago I got myself a ZX81 again. Oh what pleasures. Nostalgia galore. And that great experience of typing in little things which create immediate results.
Of course I quickly ran into some of the aforementioned limitations, so I decided to create some ZX81 support software for the Amiga: a paint program to paint nice game intro screens.
 |
| First painting with zx81paint. |
It's called "zx81paint" and runs on Amigas with OS2.0 or higher. Currently it can't load or save files, but a first painting was created successfully.
Due to the simplicity of the ZX81, the data that needs to be handled is also very simple, so there are little to no critical issues. For example the ZX81 picture itself is stored as a fixed-size array of bytes filled with ZX81 character set codes. Most of the development time is spent on putting together a pleasant and useful user interface. With the data and program structure in place, functions like line-drawing, flood fill, etc. can easily be added.
File loading and saving is currently missing - and might be one of the more challenging aspects of this little project. Several file formats used by emulators come to mind, but it would also be nice to have something that can directly be played back to the ZX81's tape-in ("EAR") jack.
There's no fixed feature list for "zx81paint", but an early release version will be put on AmiNet in a few days.
Thanks for reading, c u next time!
* * *
Jens Schoenfeld / Individual Computers says Merry Christmas with an update to P96 (Picasso96) that happens to match AmigaOS's latest version number.
According to the announcement (see link below), it's a bugfix release that addresses many little issues that were reported by users via P96's support forum.
Among the changes are updates to blitter emulation, improved use of hardware sprites (mouse pointer) that increases performance, and added support for the ZZ9000 graphics cards' dual-palette feature, removing artifacts when dragging Intuition screens.
For more details, go to Individual Computer's website:
https://icomp.de/shop-icomp/de/newsreader/items/p96-v3-2-1-herausgegeben.html
Additional sources:
http://amiga-news.de/en/news/AN-2021-12-00087-EN.html
Thomas Wenzel has release a new version of his audio player "AmigaAmp" with a decent set of bugfixes and new features. This is the list of changes, as published on AmigaAmp's website on Dec. 23rd:
Bug fixes:
New features:
Thanks, Mr. Wenzel, and Merry Christmas, too!
Go to AmigaAmp's website to download your copy:
Additional sources:
http://amiga-news.de/en/news/AN-2021-12-00067-EN.html
Another project I've been working on is slowly taking shape, and there was quite some headache involved to get it going.
In my pursuit of creating... a game! ...I've arrived at VSprites, tiles, and scrolling. The Amiga is a technical marvel, but it has it's pitfalls. So you read the docs, set up your default, low-res PAL display "View", create a "ViewPort", adjust ViewPort offsets, re-read the docs, adjust the ViewPort offsets properly, read the docs again, re-adjust... and it still behaves weirdly. At some point you try a high-res display mode. Either way, in the end result some VSprites are missing, or the scroll offset is wrong. Well, after hours and hours of experimenting, it turns out that ViewPort->RxOffset and ViewPort->RyOffset are indeed the correct variables that need to be changed to move around a larger source bitmap, but they get interpreted differently by different Kickstart/OS/chipset versions - it looks as if KS3.0 on AGA chipset, and KS3.1 SetPatch'd by OS3.9 on AGA chipset, might be messing up VSprites when scrolling, and earlier KS versions always scroll by low-res pixels, regardless of actual display (high) resolution. As a quick fix I'm focusing on what is probably still the most common Amiga configuration: Amiga 500, OCS chipset, Kickstart 1.3. I'll work on compatibility or maybe a separate version of the game later.
 |
| Basic screen mockup, to get an idea of object's sizes, and screen layout |
And a "bug" in the docs was discovered: When using VSprites, you "reserve" some hardware sprites from VSprite usage by setting/clearing bits in GelsList->sprRsrvd. The docs give contradictory information about what "reserve" actually means - bit set or clear? It has now been proven and confirmed that bits need to be set to allow VSprite usage of that hardware sprite, and bits need to be cleared to "reserve" the corresponding hardware sprite from VSprite usage. Einstein-alike.
Anyway - after overcoming these obstacles it's beginning to look like... a game!
ViewPorts are a great thing, by the way. There are a couple of limitations, but whenever you run low on colors, need a different origin for your drawing coordinates, or maybe are thinking about an alternative to a dual-playfield, a new ViewPort might solve the problem.
So now it's got a scrollable bitmap, separate status bar, sprites, tiles, game map files, and a rudimentary "physics" engine that allows sideways movement and drops. That's a huuuge step forward!
 |
| No, that's not the... game! Just an early tileset. |
Linux IFF picture viewer xiffview, which was created as a side-product of game development, now really comes in handy. I use it regularly, it has become part of my makefiles, and I add features as I need them.
When writing software that's handles data for different architectures, you have to pay attention to a lot of details. The reversed endianness (MSB on m68k vs. LSB on x86) has been mentioned many times. Also different compilers on different CPU architectures may have different data storage types - an "int" on a modern x86 machine is not be the same size as an "int" on Amiga. I encountered this just recently, when adding some code to xiffview that writes Amiga UWORD values to a text file, using something like fprintf("0x%04x", value). The UWORDs written had too many digits, too large for an Amiga 16-bit number. It looks like a bug on first sight, but the Linux x86 compiler is simply made to handle larger numbers (by default) than an Amiga C compiler. The solution is simple: you have to explicitly cast the value to a 16-bit data type, like this: fprintf("0x%04x", (short int) value).
Thanks for reading, c u next time!
* * *
Click here for an overview of all AADevLog articles
Great news from the operating system side of Amiga things: Hyperion has released AmigaOS update 3.2.1, for registered users, and for free.
In a press release published on 21st Dec. 2021 the availability of the first update to AmigaOS 3.2 was announced, along with a list of highlighted features:
Go to Hyperion's website to download the update:
https://www.hyperion-entertainment.com/index.php/downloads?view=files&parent=42
Additional sources:
http://amiga-news.de/de/news/AN-2021-12-00061-DE.html
