Huge 6.5GB of C64 demos, games, music and stuff on

Well, this is quite amazing. Jason Scott is archiving all the programs found on The Old School Emulation Center on

That means there is now a gigantic collection of retro computing history on There’s lots of stuff from the C64 to the Speccy, from the Apple Lisa to the TRS 80 there. I’m bowled over by the huge Commodore 64 collection and even found some tunes ex-Ozone member Merman created in the late 90’s. None of our demos there yet though.

One name that caught my eye was Derbyshire Ram, a swapper/cracker I have a vague recollection of. He died a few years ago but others put his huge disc collection online. I wonder if I should do the same with mine? My collection is much smaller and I think I’ll need to check any notes for personal messages but someone might find it interesting. I’m not the only one either.

Go have a look, you may find something you remember from your childhood!

A Red Storm brewed some Beatles

Earlier this evening while listening to “I am the Walrus” by The Beatles my wife asked how I knew that song. She wasn’t familiar with it you see. I replied that I had heard it used in a Commodore 64 demo and then spent the next few minutes wracking my brains for the name of that demo.

I thought it might have been made by Nato, and the title started with “Red” but nothing jumped out at me. Then I thought of Fairlight but again, nothing there except some of their demos were produced with another group, Triad! Yes, that was it!

Triad created Red Storm in 1992, it’s not the most technically sophisticated demo but it’s one of my favourite C64 demos ever. It has some nice effects but I really loved the Zoo TV inspired visuals and poetry. The music was great too, but I didn’t realise it was covers of Beatles music. Granted, it was done on a C64 SID chip so it has that 8 bit sound but it still sounds great. ‘Course, that might just be my nostalgic ears playing tricks on me.

What do you think? Yay or Nay?

C64: Wanted Dead or Alive

Bon Jovi’s “Wanted Dead or Alive” as played on a real Commodore 64. The song was digitized on an Amiga, downsampled to 4 bit audio and copied onto a 3.5″ inch disk that the Commodore 1581 drive could read from. The song data was streamed in realtime from the drive to the tiny 64Kb of memory in the computer and fed to the SID chip for our aural delight. I presume the screen has been blanked to save processing power, or the data for the sample gets dumped into screen memory.

This did require an Amiga with the Perfect Sound digitizer. I hooked up the CD player to the digitizer and then using a custom routine on the Amiga, my brother would convert the data to a 4 bit sample. Then we used a null modem cable and Novaterm with a cartridge port adapter to transfer the data to a 1581 floppy. Quite a bit of work went into this.

20 years ago I recorded my own voice onto a cassette saying the word “Ozone” (the name of my demogroup) and I figured out how to sample my voice using the Commodore cassette deck hooked up to the C64. I can’t remember now what memory register it used, I’ll have to search my disk images or examine a C64 memory map one of these days. The quality was terrible but if you knew what was being said you could make it out. It had to be kept short because I’d ran out of memory! I think I used it in the last part of my demo “Awareness of Reality”. (via)

Commodore 64: 8 Bit Legend

Impressive video showing off some of the most popular games of the C64 and the biggest or most famous groups in the C64 demoscene. Must have taken ages to make.

Skip forward to 10:00 into the video for a message from Jim Butterfield. Though recorded in the 80’s I presume, the message still applies. Programming can be fun.

(via Jaz)

Happy Birthday Commodore 64!

issue 50 of Zzap 64!
Issue 50 of Zzap! 64

The Commodore 64 is 30 years old this year and it went on sale in August 1982 so I think it’s about time I wished it a happy birthday. Back then I was messing on a Commodore Vic 20 (or more likely it was 1984 or so), then I had a Speccy and I didn’t get my hands on a C64 until 1989. It was already declining somewhat but it still had a few years of life left in it. Issue 50 of Zzap! 64 was the first issue of that famous magazine I owned. My brother and I bought it in Paul’s Street Shopping Centre! The newsagent is long gone but I have that issue around here somewhere ..

Matt Allen visited a primary school and a secondary school and asked kids there what they thought of the Commodore 64. I don’t think they were impressed by loading errors and long loading times. He probably should have brought a 1541 disk drive and an Action Replay cartridge!

Continue reading “Happy Birthday Commodore 64!”

My early memories of programming

My earliest memories of programming are directly related to the pain of not being able to save my work.

The first proper computer my family owned was a Commodore Vic-20. I guess my parents bought it in 1984 or 1985 but it might have been earlier. The Vic-20 came out years before but this was recession hit 80’s Ireland. I’m pretty sure the computer was bought in O’Callaghan’s shop, where the betting shop is now on Pembroke Street.

I remember copying a flying bird BASIC listing from the Vic-20 manual one school morning, and I think I made it fly left and right too. What made it stick in my mind was the anguish I felt because I couldn’t save it. We had a Vic-20 you see but we didn’t have a datasette that could record or play back data on cassette tapes. I left the machine on while I went to school which was risky because they had huge heavy power supplies that had a tendency to overheat (not that I knew that then!) Thankfully we did get a datasette later because I remember playing Wacky Waiters on it. Or it might have been some sort of interface that let me plug a regular cassette player into the Vic-20. Chip Electronics sold them in clear plastic bags I think. All a little hazy now unfortunately!

So, thanks to this site I was able to track down a scanned copy of the Vic-20 manual and immediately jumped to the Flying Birds bit. A little bit of rose tint nostalgia on a murky Friday evening almost 30 years later.

What got you into programming?

Digital Acid

“Turn the lights off, stand in the middle of the room and wave your arms about frantically….”

Watch it fullscreen, but not if you’re averse to flashing lights..

Smiley’s People, a BBC podcast I listened to recently inspired me to look up this old Ash & Dave C64 demo. Unfortunately the podcast is not available any more.

Prince of Persia: the Apple II source

It’s been a good few months for the 8 bit versions of Prince of Persia. Last October saw the release of a C64 version. Yesterday the original source code for the Apple II version was uploaded to github! Read about how Jason Scott recovered that source code from 20 year old disks (similar to what I did recently!)

The game was originally written in assembler so the source code was already out there. How? Machine code is the language a machine understands and assembler is a human representation of that machine code. For example, the machine code “A9 00 8D 20 D0” is actually this more readable assembler: (that inserts the value 0 into the memory location $D020)

LDA #00
STA $D020

The assembler code released yesterday goes one step further. It uses labels, variables and comments. See BOOT.S as a good example. Variables are defined at the top and labels are used throughout making it a lot easier to deal with moving and adding code around. Look for the text “skewtbl” where you’ll find a simple loop that reads in data from memory and inserts it into 2 registers.

:0 ldy sector
 lda skewtbl,y
 sta $3d
 lda sectaddr,y
 beq :1
 sta $27
:rdsect jsr $005c
:1 dec sector
 bne :0

 lda SLOT
 jmp $900

skewtbl hex 00,0d,0b,09,07,05,03,01
 hex 0e,0c,0a,08,06,04,02,0f

sectaddr hex 00,09,00,00,00,00,00,00
 hex 30,31,32,33,34,00,00,00

Jordan Mechner puts it more poetically:

Non-programming analogy: Video game source code is a bit like the sheet music to a piano sonata that’s already been performed and recorded. One might reasonably ask: If you have the recording, what do you need the sheet music for?
You don’t, if all you want is to listen and enjoy the music. But to a pianist performing the piece, or a composer who wants to study it or arrange it for different instruments, the original score is valuable.

Props to this Slashdot post for the extra links. Also worth a look is the development diary of the C64 version and there are videos showing how the game was made back in 1985!

RIP Jack Tramiel

Jack Tramiel, the man who founded Commodore and brought Atari back from the dead died on Sunday at the age of 83. RIP.

lemon64 thread.

Here’s a great Cringley post on Jack Tramiel.

What I learned this week that I didn’t know before was that the people who worked for Tramiel really loved him. Jack Tramiel was no Steve Jobs: he was better.

The Commodore 64 was a phenomenal success. People forget that in the early 1980s the C64 outsold the Apple ][, IBM PC, and the Atari 400/800 combined. Commodore was the first to sell computers through discount retailers, opening whole new distribution channels. And don’t forget it was Jack who saw the value in Amiga, which in many ways set performance targets that took Apple years to beat. It would have been very interesting to see how the Amiga would have faired had Jack Tramiel stayed at Commodore.

I should have written more in this post yesterday but I didn’t have time. The Commodore 64 was the first computer I really obsessed about and learned loads about. Previously I had dabbled in BASIC using the Vic 20 and then a 48K Spectrum but after I got a C64 I learned how games were coded, learned quite a bit of assembler and produced and distributed my first software. That software wasn’t amazing or anything but I was always learning new things.

So, thanks Jack for creating the company that created such an amazing computer that had a huge influence on my life. When Steve Jobs died last year there were glowing blog posts about his machines. I vaguely recall an Apple II in a school lab but I hardly ever used it. The C64s in the same lab were much more interesting!