An Intro to 6502 Assembler

In the bad old days of the 80s and 90s computers weren’t as fast as they are now. You had to fill ’em up with leaded fuel and they were noisy and hot and you had to keep the windows open to let the fumes out.

Well, maybe not. They weren’t as fast as the handheld machines in our pockets now but I’ll bet that a larger percentage of users back then at least tried to code something. People had to because it wasn’t always easy to get games. You had to go down the shops and get out of the house to buy any new software! You had to open the manual to find out how to load anything!

So it was that I figured out that I’d rather be coding than playing games, and with the purchase of a book on assembly (that has sadly gone missing in the last year) I got busy and created a bunch of demos on the C64.

I wish I’d had this video to watch when I was starting out! If you’ve done any sort of assembly programming it won’t be anything new but it’s presented in an easy to understand manner and is worth watching if you’re at all curious about how computers work because a lot of the terminology is going to apply to other systems too.

I’m really looking forward to seeing the rest of this series. I want to get back to doing some assembly programming. There’s plenty of documentation out there but it’s a matter of finding the time and energy to do it.

We Come in Peace Demo

This is just amazing. All done on a lowly C64 by Censor Design and Fairlight. Grab the demo from csdb. Unfortunately it doesn’t work in the SD2IEC because it has a fastloader. I should buy an Ultimate II+ or Ultimate 64 shouldn’t I?

C64 Spotted in Cash Connectors

In Cash Connectors, North Main Street Cork. €119.99 for a C64, datasette and I think 4 games. No mention of whether it’s working or not or even if it comes with a power supply.

First time I’ve seen a C64 in a shop here in years. Last time might have been in Maddens on Princes Street some time in the early nineties.

New C64 Adventures

It’s no secret that I’ve been a fan of the Commodore 64 for many years. It was my family’s third computer, after a Vic20 and 48K ZX Spectrum. I don’t count the Telesport, I couldn’t program that! The C64 was my main computer from 1989 to about 1994 and I went from programming in BASIC to exploring the depths of the machine with an Action Replay cartridge and programming demos in assembly. Since the late nineties I contented myself by using different emulators like PC64, Frodo and Vice but in the last year or so I’ve wondered about owning one again.

What I would consider the first resurgence of the C64 world for me was finding the Commodore Format blog. There’s also Zzap64.co.uk which has been going for ages but it’s an invaluable archive site. The CF blog has regular blog posts about this old magazine and features about new developments and I love it. I could blame the community of C64 fans on Twitter, the C64 sub Reddit and various C64 groups on Facebook. They’re always going on about playing this game or that game on “real hardware”, or how a certain demo doesn’t look perfect in an emulator. But really, I’d say it was the fanzine FREEZE64 that finally piqued my interest again. It’s a great read and Vinny, who publishes it, is always posting photos of the things he’s doing on the machine. The fanzine brings me back 30 years to when I first got the machine.

Peer pressure finally won. I bought a C64 on eBay and it arrived yesterday!

I’ve always wondered if it was possible to use a modern controller with the C64 and there are a few adaptors to do that. One of those is the TOM Rev2 adaptor and extension cable. It’s due to arrive at the end of the month, so fingers crossed it works well.

I have a 1541 II disk drive in the attic but there are better storage solutions available for the C64 now. One of those is the SD2IEC, an SD card reader for the machine. I bought the thefuturewas8bit SD2IEC and Fastload Cartridge. Conveniently an 8GB SD card can be purchased which is enough room to fit practically every C64 game on it!

The C64 produces a composite video signal and a video signal that was s-video before that was even a standard. My monitor doesn’t have either RCA/phono sockets, SCART or s-video port but it does have HDMI so I needed a converter. Scouring websites and forums for information about the best way to connect a C64 to HDMI is exhausting. Recommendations to buy one converter are followed by discouraging remarks from others about the same device. In the end I checked Amazon reviews and this Ex-Pro video converter seemed to fit the bill. It has phono and s-video sockets too!

Finally, I needed a video cable. I messed up and bought a C64 DIN to phono/RCA cable instead of s-video, but it works well enough. The screen image is nowhere near as clear as an emulator like Vice but I’ve ordered a similar cable with an s-video plug that I hope will be better.

The first thing I tried was one of my demos, Bits ‘n’ Bobs and it was amazing to see it run! The picture isn’t perfect and especially on this wide monitor everything is stretched. 4:3 it is not!

In a later demo, the CFORCE demo, I displayed a FLI picture in one part. That picture annoyingly bounced up and down which is probably a result of displaying on a modern monitor. On an old CRT it was fairly solid, apart from the usual fuzziness when displaying FLI pictures.

Getting it all set up was a challenge, mainly to find space for it, but I made room. Using the “picture in picture” mode of my monitor the display is smaller and the effects of the component cable less noticeable.

The SD2IEC and fastloader cartridge are a game changer. No more fiddling with ageing physical disks that are likely to be unreadable. I’m already missing the Action Replay though. F1 to load and F3 to list a disk is just that tiny bit more convenient than the Epyx Fastloader equivalents.

I just bought an Over Voltage Protector as I’m paranoid. This machine came with a Micro Mate power supply but power supplies fail and the C64’s chips are sensitive to more than 5.5V. This should hopefully stop that happening if the PSU fails.

Now I’ve got one of these machines I want to get an Ultimate 64. It’s a fascinating bit of kit, and the price of it put me off before, but it’s actually cheap when you consider everything it does!

So, what games should I play on it? I’m without a joystick or controller so it’s keyboard only. I asked on Twitter and I have to try Thrust, The Sentinel, West Bank, Skooldaze and the recently released Neutron on it as they all support keyboard. I already played Stunt Car Racer which brought back plenty of memories. 🙂

Edit: The s-video cable arrived and the video quality is much better. There’s still faint vertical lines but I can live with those.

Edit on 12th June: I just received this female RCA to 3.5mm earphone jack and I can finally hear the SID on decent speakers! The sound from my HDMI monitor is woeful so I’ve been looking forward to this for a while.

A SNES Mini found a new home

The first Nintendo console I owned was the Gameboy Advance. The earlier Nintendo machines passed me by as I was busy coding on the C64, messing with the Amiga and PCs and college then kept me busy!

I never owned a SNES and Nintendo 64 and rarely even used the real hardware. The only game in the SNES Mini collection that I’m nostalgic about is F-Zero as I loved playing that on the Gameboy and it plays perfectly on this diminutive machine.

This is a lovely piece of kit though. I like the menu system and the two controllers are wonderful. Now I know why people go on about these and seek out their modern equivalents in 8bitdo equipment.

Apart from games I’m looking forward to tinkering with the machine, and maybe adding a C64 core although the lack of a proper keyboard can cause problems..

The Great Giana Sisters on Ebay

I was going to make a joke about how a clone of The Great Giana Sisters had been released on the C64 a few weeks ago, but I would hazard a guess that only a handful of my readers will have the faintest idea what I’m talking about. Instead, you’ll probably remember that most gaming sites were abuzz with the news that Super Mario Bros had been released for the C64. That excitement then turned to fear and anger as Nintendo issued a takedown notice to one blogger who had a download link on their site. They have to protect their IP but the game is still available in several places including the Internet Archive and should be easy enough to find in the future.

If you’re at all interested in Super Mario Bros then grab your copy as quick as you can, just in case a massive database of copyright works is unleashed on the Internet blocking everything no matter how old it is.

The conversion of the game to the C64 is more than just a direct port. Both machines use the same (or similar?) CPU, a modified 6502 in the case of the NES and 6510 in the C64. The developer ZeroPaige spent 7 years modifying the raw assembler from the NES so it would work on the C64. He had to modify the graphics system to use C64 sprites and the sound system had to be reworked to use the SID chip of the C64.
The port also takes advantage of any extra hardware you might have plugged into the C64, or even uses the extra power of a Commodore 128 if you’re using that. Here are two videos showing the game off on a C128 and also on a Turbo Chameleon V2, an FPGA based C64 machine. The game suffers slowdowns on an original C64 so it’s best played when the machine has some help, or in an emulator. I have a C64 DTV. I wonder how hard it would be to get it running on that?

Super Mario Bros on a Turbo Chameleon V2
Super Mario Bros on a Commodore 128D with SuperCPU

It seems Nintendo aren’t really interested in the C64. Many years ago Gary Lidon and Gary Penn created an SMB demo for Firebird who sent a video of it to Nintendo. They responded with a cease and desist order!

Rainbow Arts apparently did the same and were rebuffed but they reused their code and cheekily created The Great Giana Sisters. Nintendo promptly came after them at the time and the game was taken off the shelves within weeks. Pirated copies are simple to find but the original must be very rare. A version of the game with the main character changed to Mario did find it’s way online but it’s basically Giana Sisters. No bad thing since The Great Giana Sisters is a great game. It’s one of my favourite C64 games.

After that detour down Nintendo lane, let’s get back to reality. If you want your very own physical copy of The Great Giana Sisters then check out this Ebay auction. Priced at an eye watering £199.99+postage I don’t think it’ll be an impulse buy but some collector is sure to snap it up.

As a historical note, there are two conversions (Atari and Ocean) of the original Mario Bros for the C64 if you really want to play it. I haven’t played either of them. I didn’t even know they existed until a couple of years ago!

Prodigy in Wonderland XIII

The death yesterday of Keith Flint left many shocked and reaching for their CD collections but I remembered that one of their songs was featured in a Commodore 64 demo.

Censor Design sampled Prodigy’s “Smack my Bitch Up” and used it as the sound track to the final part of their excellent demo Wonderland XIII. Click play on the video above to see it in action. It’s really amazing!

It’s worth watching the whole video but if the embedded version above doesn’t load at 7:33 then load it from here instead or here’s another video of the music played back by two SID chips which IMO sounds even better!

For those at the back who don’t know, the C64 was released in the early 80s but developers made it work magic and do things thought impossible, such as in this case playing sampled sound!

Edit (2019-03-22): Here’s a version of Voodoo People from Bad Boy by Samar Productions. Amazing what the SID can do!


Road of Excess

Road of Excess by Triangle is a Commodore 64 demo released in 1990 that totally blew me away when I saw it.

Yes, you could play Breakout in one of the parts if you had a joystick plugged into the computer. This demo had quite a few interactive parts.