DYCP 2018 (A8)

So Blok Copy on the Atari 8-bit wasn’t the only Cosine contribution to the New Years Disk 2018 because Cosine also churned out a little demo called DYCP 2018. And yes, I know that’s a terrible title but I was taking the Roy Walker approach to naming for this one and, after scratching my head for a few hours, nothing better presented itself!

The main reason for this one is that Andy Vaisey sent along a great cover of the loading music from Uridium 2 on the Amiga; he’d produced it whilst getting his head around the Atari 8-bit’s POKEY sound hardware but the tune was triple speed (so is called 150 times a second rather than just 50) and needed code around it which wouldn’t mind being interrupted from time to time if you’ll excuse the “pun”. I wasn’t thinking about that as I delved through my workfiles but realised that one of my five year old DYCP prototypes would work in that respect and spent a morning making the two work together.

Why is there a copy of the C64’s power up screen here…? That’s mostly because the DYCP routine has been written the “C64 way” using one character set and arranging everything in memory to make drawing the letters as fast and efficient as possible.

Blok Copy (A8)

Blok Copy on the Atari 8-bit is an action puzzle game that I originally wrote for the Atari 2600 but bodged the code so badly that it crashes real consoles – one of these days that’ll need sorting out – before porting the game logic to the Commodore PET and onwards to other platforms. And now there’s a new version in town, during the Christmas period the source code was pulled apart and introduced to the Atari 8-bit before some demo-like vertical colour splits were added to make it look pretty and Andy Vaisey produced a lovely rendition of the Sean Connolly tune Sporting Chance which has been the Blok Copy soundtrack since the C64DTV2 version. This new iteration was released as part of the New Years Disk 2018

The gameplay is simple enough, the playfield has five rows of seven tiles which are randomly mixed up at the start of a level and the player has to shift them around until the first column is all 1 tiles, the second has all 2 tiles and so on. A joystick in port 1 controls the on-screen cursor and holding fire whilst moving up or down will shuffle the current column accordingly with left or right moving the current row. The time limit might seem generous on the first level where only three computer-controlled moves take place, but won’t feel so as the game progresses.

The Atari 8-bit code and graphics were ported from the C64 version, but before that happened I wanted to make some tweaks; the source has been “sanitised” to make it more readable, the in-game graphics reworked so that it’s easier to tell the tiles apart – people complained about that with the previous version – and a couple of bugs squidged which were introduced when reworking the PET code. That means there’s a new version for the C64 too, so welcome to Blok Copy RX which was also released today!

Happy new year and all that gubbins… there’ll be a second post along in the near future for the other release from today!

MD201706 (accelerated C64)

Another release so soon? MD201706 is merely a plotter with some cosmetic niceness, but the code is a little unusual; it needs a SuperCPU (which can be emulated in recent versions of VICE and, unless it’s lying, it should run on either PAL or NTSC) or the Turbo Chameleon set to 6MHz or faster in order to run. Its single buffered and can clear, update and draw four hundred points a frame courtesy of the expansion hardware. It isn’t fully using the capacity of either device, the current firmware of Chameleon with its speed set to “no limit” is slightly faster than the SuperCPU but I restricted myself to 6MHz in case that top speed changes downwards with future updates.

A few people are probably going to ask “why” and the simple answer is “because”, but I’d actually been prodding around my unrolled plotter which was used in MD201704 on the C128, using 2MHz mode in the borders and found myself wondering just what my Turbo Chameleon could do with it. Then Wolf 3D for the SuperCPU arrived and I decided to make my code run with both. As always, GitHub is the source for… erm, the source and questions can be passed on in the usual manner.

This is probably going to be the end of season two for the Monthly Demo series because I want to take a little break to work on games… and yes, I’m already braced for the influx of responses that’ll probably get, so will be running away before this post goes out!