*Warning* C64 Lack of Love on this board!

[yojo!]

Regarding Andy Braybrook; I don't know about his C64 work(never owned one) but his Amiga games were spectacular; His Rainbow Island conversion was close to arcade perfect (for 80s standards anyway). Virocop, Fire and Ice and Uridium 2 showcased his talent as a programmer. I think he did some work on First Samurai too but I'm not sure. I remember reading one of his article on programming tricks in one Amiga magazine back in the days...
As for 80s programming gods; I think that Rafael Cecco must be in the top 3.

[mr_m0nks]

sorry to be a pain but ive never heard of the SID having a crystal oscillator (in fact ive never heard of a crystal oscillator at all)

it was basically a small digitally controlled analog synth

Only the filtering is analog; the actual synthesis is digital. The "smoking gun" here is that it doesn't support a sine wave, which is easy to do with analog and hard to do with digital. However, people who have looked at the output on a scope also say that it very clearly looks to be DAC output.

as i said in my orig post it is a digitally controlled analog synth. The Oscillators are controlled via digital signals ( as is the filter and other modulation sources) however the audio signal is an analog voltage. a lack of sine wave is no indication that an oscillator is digital and in practice a triangle wave is easier to produce from a multi waveform oscillator and is almost audibly indistinguishable from a sine. (note that the orig minimoog oscillators dont offer a sine but do offer a tri wave, and thats as analog as you can get!)

and i dont know about sine waves being hard to do in digital. i know in CSound when programming oscillators it is alot easier to program a sine wave than a complex waveform as every harmonic must be individually entered with its relevant amplitude. (it may be a little different in digital hardware but ive never built a digital oscillator!)


In synth terms they would be called DCO's or Digitally Controlled Oscillators, as oppose to Digital Oscillators (which if used with an analog filter would usually have a D/A converter built in)

[Ex-Cyber]

as i said in my orig post it is a digitally controlled analog synth. The Oscillators are controlled via digital signals ( as is the filter and other modulation sources) however the audio signal is an analog voltage.

Of course the output is analog, but that's because the D/A conversion is done internally (see below).

a lack of sine wave is no indication that an oscillator is digital and in practice a triangle wave is easier to produce from a multi waveform oscillator and is almost audibly indistinguishable from a sine. (note that the orig minimoog oscillators dont offer a sine but do offer a tri wave, and thats as analog as you can get!)

Fair enough; I can buy that explanation for lack of a sine wave. Still, it is "easier" to actually synthesize a sine wave with analog circuitry than with digital, because the math involves a power series, which are mathematically straightforward but hard to evaluate in real time. With analog circuitry you can use components that naturally have exponential characteristics. The other waveforms are all essentially linear, so it's pretty much a matter of manipulating the input and output signals of a counter.

and i dont know about sine waves being hard to do in digital. i know in CSound when programming oscillators it is alot easier to program a sine wave than a complex waveform as every harmonic must be individually entered with its relevant amplitude. (it may be a little different in digital hardware but ive never built a digital oscillator!)

Triangle, sawtooth, and square waves can all pretty much be implemented with counters and some extra logic. Combining these all into a unified block is not trivial but I think a decent engineer shouldn't have a great deal of difficulty with it. Noise can be done (and is in the SID; IIRC someone even reverse-engineered the tap configuration) with a linear feedback shift register. Some early digital synths have sine waves, but AFAIK that was done by basically having a tiny ROM for the sine wave samples (or maybe they were actually triangle waves, as you mention).

Anyway, I didn't want to spend the time last time to dig up this interview, but here it is from the man himself:

It's pretty brute-force, I didn't have time to be elegant. Each "voice" consisted of an Oscillator, a Waveform Generator, a Waveform Selector, a Waveform D/A converter, a Multiplying D/A converter for amplitude control and an Envelope Generator for modulation. The analog output of each voice could be sent through a Multimode Analog Filter or bypass the filter and a final Multiplying D/A converter provided overall manual volume control.

As I recall, the Oscillator is a 24-bit phase-accumulating design of which the lower 16-bits are programmable for pitch control. The output of the accumulator goes directly to a D/A converter through a waveform selector. Normally, the output of a phase-accumulating oscillator would be used as an address into memory which contained a wavetable, but SID had to be entirely self-contained and there was no room at all for a wavetable on the chip.

The Sawtooth waveform was created by sending the upper 12-bits of the accumulator to the 12-bit Waveform D/A.

The Triangle waveform was created by using the MSB of the accumulator to invert the remaining upper 11 accumulator bits using EXOR gates. These 11 bits were then left-shifted (throwing away the MSB) and sent to the Waveform D/A (so the resolution of the triangle waveform was half that of the sawtooth, but the amplitude and frequency were the same).

The Pulse waveform was created by sending the upper 12-bits of the accumulator to a 12-bit digital comparator. The output of the comparator was either a one or a zero. This single output was then sent to all 12 bits of the Waveform D/A.

The Noise waveform was created using a 23-bit pseudo-random sequence generator (i.e., a shift register with specific outputs fed back to the input through combinatorial logic).The shift register was clocked by one of the intermediate bits of the accumulator to keep the frequency content of the noise waveform relatively the same as the pitched waveforms. The upper 12-bits of the shift register were sent to the Waveform D/A.

Since all of the waveforms were just digital bits, the Waveform Selector consisted of multiplexers that selected which waveform bits would be sent to the Waveform D/A. The multiplexers were single transistors and did not provide a "lock-out", allowing combinations of the waveforms to be selected. The combination was actually a logical ANDing of the bits of each waveform, which produced unpredictable results, so I didn't encourage this, especially since it could lock up the pseudo-random sequence generator by filling it with zeroes.

The output of the Waveform D/A (which was an analog voltage at this point) was fed into the reference input of an 8-bit multiplying D/A, creating a DCA (digitally-controlled-amplifier). The digital control word which modulated the amplitude of the waveform came from the Envelope Generator.

The Envelope Generator was simply an 8-bit up/down counter which, when triggered by the Gate bit, counted from 0 to 255 at the Attack rate, from 255 down to the programmed Sustain value at the Decay rate, remained at the Sustain value until the Gate bit was cleared then counted down from the Sustain value to 0 at the Release rate.

A programmable frequency divider was used to set the various rates (unfortunately I don't remember how many bits the divider was, either 12 or 16 bits). A small look-up table translated the 16 register-programmable values to the appropriate number to load into the frequency divider. Depending on what state the Envelope Generator was in (i.e. ADS or R), the appropriate register would be selected and that number would be translated and loaded into the divider. Obviously it would have been better to have individual bit control of the divider which would have provided great resolution for each rate, however I did not have enough silicon area for a lot of register bits. Using this approach, I was able to cram a wide range of rates into 4 bits, allowing the ADSR to be defined in two bytes instead of eight. The actual numbers in the look-up table were arrived at subjectively by setting up typical patches on a Sequential Circuits Pro-1 and measuring the envelope times by ear (which is why the available rates seem strange)!

In order to more closely model the exponential decay of sounds, another look-up table on the output of the Envelope Generator would sequentially divide the clock to the Envelope Generator by two at specific counts in the Decay and Release cycles. This created a piece-wise linear approximation of an exponential. I was particularly happy how well this worked considering the simplicity of the circuitry. The Attack, however, was linear, but this sounded fine.

A digital comparator was used for the Sustain function. The upper four bits of the Up/Down counter were compared to the programmed Sustain value and would stop the clock to the Envelope Generator when the counter counted down to the Sustain value. This created 16 linearly spaced sustain levels without having to go through a look-up table translation between the 4-bit register value and the 8-bit Envelope Generator output. It also meant that sustain levels were adjustable in steps of 16. Again, more register bits would have provided higher resolution.

When the Gate bit was cleared, the clock would again be enabled, allowing the counter to count down to zero. Like an analog envelope generator, the SID Envelope Generator would track the Sustain level if it was changed to a lower value during the Sustain portion of the envelope, however, it would not count UP if the Sustain level were set higher.

The 8-bit output of the Envelope Generator was then sent to the Multiplying D/A converter to modulate the amplitude of the selected Oscillator Waveform (to be technically accurate, actually the waveform was modulating the output of the Envelope Generator, but the result is the same).

Hard Sync was accomplished by clearing the accumulator of an Oscillator based on the accumulator MSB of the previous oscillator.

Ring Modulation was accomplished by substituting the accumulator MSB of an oscillator in the EXOR function of the triangle waveform generator with the accumulator MSB of the previous oscillator. That is why the triangle waveform must be selected to use Ring Modulation.

(from here)

[mr_m0nks]

Well you learn something everyday

my apologies , id never read that interview (thanks for the link)

no wonder nothing else sounds like a SID except maybe the odd ensoniq synth


i cant say i fully understand the math behind what he's saying but i cant think of any other digital oscillator that works like that, most as you say use small samples of actual waveforms (usually as small as a single cycle) to generate a signal.

[Ex-Cyber]

Well you learn something everyday

my apologies , id never read that interview (thanks for the link)

no wonder nothing else sounds like a SID except maybe the odd ensoniq synth

Yeah, I don't mean to denigrate the SID at all when I say it's not an analog synth. It is different, just not for that reason. The really impressive thing is that it turned out so well despite the huge compromises that had to be made. It's fun to imagine how things would have played out had it not been rushed.

i cant say i fully understand the math behind what he's saying but i cant think of any other digital oscillator that works like that, most as you say use small samples of actual waveforms (usually as small as a single cycle) to generate a signal.

That approach requires memory to store the samples as well as counters to sequence the samples. In the early days it was probably quite a bit cheaper to synthesize the waveform directly from the counters. A counter naturally outputs a discrete sawtooth wave without any special effort. For a triangle wave you could reverse the count direction halfway through the cycle. For a square wave you could just take a suitably significant bit from the counter. Not surprisingly, SID's approach is more flexible than this, but those are the basics.

[neorichieb1971]

If anyone can find me the Tetris tune I'd appreciate it. That tune just somehow mesmerises me. Its like a heart beating in tune.

[Emperor Fossil]

Direct download the SID file: Click! From lemon64.com

You'll need something like SIDplay to play it (or maybe the SID plugin for winamp).


And while I'm on the c64 subject, here are a few YT vids:

Armalyte:

Level 1 - Level 2 - Level 3 ...in fact, all 8 levels are up there. Link.


Io:

Level 1 -Level 2 - Level 3 - Level 4


Also, I'm not a big fan of Katakis, but many people love it:

Longplay part 1 - part 2 - part 3

[Herr Schatten]

And while I'm on the c64 subject, here are a few YT vids:

Armalyte:

Level 1 - Level 2 - Level 3 ...in fact, all 8 levels are up there. Link.


Io:

Level 1 -Level 2 - Level 3 - Level 4


Also, I'm not a big fan of Katakis, but many people love it:

Longplay part 1 - part 2 - part 3

Io. What an amazing game. Now that I have rigged up my C64 along with the other consoles I need to play this again. I used to be able to 1CC it, but I doubt I'd get through the first stage if I tried today.

Watching the videos in a row makes it even more apparent how many things Io did get right, which Armalyte didn't.

[Emperor Fossil]

Man, Armalyte's a great game. Quit yer hatin' on it, dagnabbit!

[Herr Schatten]

Man, Armalyte's a great game. Quit yer hatin' on it, dagnabbit!

It's not quite as great as most people seem to remember it. It's okay-ish and I wouldn't say I hate it, but, nostalgia goggles removed, I think it's terribly flawed and doesn't deserve half the praise it gets.

[Emperor Fossil]

I dunno... I read your review, and I have to ask, were you (or are you) familiar with the battery and generator powerups and what they do... because you don't really mention them or they way they contribute to one of the key factors in the game, ie: striking a balance between increasing the effectiveness of your always accessible but less powerful primary firepower versus increasing the accessibility of your much more powerful but less accessible secondary weapons. Maintaining that balance is one of the main things that makes the game enjoyable and separates it from other c64 shooters, imo.

And I don't know if you captured those screenshots yourself, but the colour saturation in them is jacked up way higher than normal. It doesn't normally look so eye-gougingly lurid.

However I do agree that the way the explosions keep moving is a problem. I understand there were technical reasons behind that decision, but if they had to have moving explosions and couldn't even make them a different colour, they could at least have made the explosion animation shorter so it was less distracting.

I also agree that the bosses generally aren't very exciting/challenging (some are clearly designed only with 2p in mind), however they shouldn't take ages to kill -- usually under 30secs, provided you've built up your generator + batteries.

[MJR]

I remember when Armalyte came around - I used to think its sh*t until I discovered the battery powerups and different lasers you can switch with C= key. Then I began to absolutely love that game!

Io can be nice too, if you can get past the first level, which is totally annoying, until you get your powerups.

To think of it now, those two (and uridium) are actually better than many, many coinop shooters. Have you ever tried checking out in mame all the crap they used to put out in arcades back in the 80's?

[Herr Schatten]

I dunno... I read your review, and I have to ask, were you (or are you) familiar with the battery and generator powerups and what they do... because you don't really mention them or they way they contribute to one of the key factors in the game, ie: striking a balance between increasing the effectiveness of your always accessible but less powerful primary firepower versus increasing the accessibility of your much more powerful but less accessible secondary weapons. Maintaining that balance is one of the main things that makes the game enjoyable and separates it from other c64 shooters, imo.

I'm the first one to admit that my review is crap. It was one of the first I did and it really fails to mention important things. But yes, I was well aware of the battery and generator powerups and the secondary weapons system is really one of the best things about the game.
However, that doesn't really change my perception of the gameplay much. I still think that the levels are (too) long, same-y and dull, that the enemy formations seem random rather than well thought-out and that the flying enemies don't have distinct looks and behaviour. The latter one can be seen done in a good way in Io, where enemies that look the same usually behave the same (or at least similarly).

If I re-wrote the review today, it would tell more about the in-depth gameplay, but the score underneath would still be the same. (Mind you, "5" means "average" to me, not "terrible". I'm not bashing the game, I just think it's overrated.)

And I don't know if you captured those screenshots yourself, but the colour saturation in them is jacked up way higher than normal. It doesn't normally look so eye-gougingly lurid.

I know. I have a real C64 and the original game at home. The colours in those screenshots are the standard palette in my emu, which works fine for most other games, but not for Armalyte, apparently. My criticism of the graphics doesn't come from the choice of colours, however, it's based on the art direction. I think it's a bad decision to cycle the same background blocks through 3-4 colour schemes in each level, as it takes away from the levels's uniqueness until the whole game blurs into an un-memorable mess. Same for the enemies. I'd rather have formations composed of grey, blue or red enemies instead of having all of them on screen at once.
Also, they clearly try to copy Bob Stevenson's style without actually understanding how it works. Just copying his colour palette doesn't do the trick. Io just oozes style. Armalyte (IMO) doesn't.

I also agree that the bosses generally aren't very exciting/challenging (some are clearly designed only with 2p in mind), however they shouldn't take ages to kill -- usually under 30secs, provided you've built up your generator + batteries.

Yes, but it certainly feels longer. I also don't like the reliance on the generator and batteries much, but that's a matter of taste I suppose. I also dislike the length of the boss fights in TF4 and their reliance on certain weapons, after all.
Bosses in Katakis are awful, too, but the game gets away with it due to superior level design.

[Emperor Fossil]

However, that doesn't really change my perception of the gameplay much. I still think that the levels are (too) long, same-y and dull, that the enemy formations seem random rather than well thought-out ...

Fair enough. I really like the frantic, swirling nature of the attack waves, but I can certainly see how it might not be everyone's beverage of choice.

For me, one of the other big pluses for Armalyte is the flexibility of the player's drone ship. I like the way it works as a movable shield as well as a source of firepower (as you mentioned in your review), and also the way you can lock it and leave it to take care of one wave while you go deal with another.

... and that the flying enemies don't have distinct looks and behaviour. The latter one can be seen done in a good way in Io, where enemies that look the same usually behave the same (or at least similarly).

Yeah, that's a good point. It never really bothered me with Armalyte, but I agree it is better to have set enemy types/behaviours.

If I re-wrote the review today, it would tell more about the in-depth gameplay, but the score underneath would still be the same. (Mind you, "5" means "average" to me, not "terrible". I'm not bashing the game, I just think it's overrated.)

grrgrghghgh... OK, I'll shut up about it. I guess Armalyte is to you is as Katakis is to me.

As far as the graphics go, I quite like the style and level design in Armalyte, and I don't mind the colour changes during the level, but I agree that Bob Stevenson's work in Io is superior. Io is just so nicely done, and I particularly like the way the bosses managed to still be interesting and challenging despite being stationary, although admittedly the skull at the end of level 2, while very pretty, is a pushover... gotta love the cannon on level 3, though.

[NAVVARR]

3 pages and still nothing from Minter?

"Revenge of the mutant camels" FTW!

The same thought occurred to me as well but I found that most of Jeff's best games were on the Vic20.- His versions of Matrix, Lazer Zone, Hellgate and Gridrunner looked and played better on the Vic's chunkier screen. IMO

[dave4shmups]

What's up with Nintendo's lack of love for the C64 for this region?? I have a good deal of appreciation for the SMS, but I'm pretty sure more people in the US owned, and gamed on, a C64. Just a few months ago, we had a dad come into our store who mentioned Jumpman! I realize Commodore products were bigger in Europe, but the C64 was still huge over here.

EDIT: Thanks Emperor Fossil for putting up IO! The first level looks like blast; the bullets were flying out of that boss almost like Psikyo shmup!

I guess the best you can do over here, is get one of those C64 plug-and-play sticks. Although I would imagine that purchasing a C64 and software would be easier and cheaper then Amiga-I could be wrong, though. People have mentioned emulation, though, and no mods have stepped in-is it legal for this platform?

[Guardians Knight]

ahh my first computer!

indeed my first game i ever played was River Raid, disapointed no one has mentioned this kingly of shoot em ups.

also big love to Dr Destructo and Paradroid - both boarderliners at best but also immense in the gameplay department.

so who still ownes the original hardware? I got the old breadbin somewhere in my room, also got a HUGE amount of old tapes, probs send most of them to the charity shop or something, altho keeping the absolute gems even tho soon the tapes will probs cease to play.

end of my little trip down memory lane for now, might even plug the old girl in and give some proper retro games a whirl....

[mr_m0nks]

i have 2 C64's at the moment, my first proper computer too, there has just always been something special about it.

Paradroid is a fantastic game! In fact i think it has been released on the Wii DL service too (Spadgy has just been talking about it over on the 2d Gaming Forums)


btw if you are looking to get rid of some old tape games i might be interested! PM me

[dave4shmups]

So what about getting into C64 gaming in this country??

[Guardians Knight]

@ mr_m0nks:

i'll take some time to sort some stuff out soon and let you know mate

[spadgy]

I was a dedicated Commodore fanboy as a kid, but at 28 that puts me firmly in Amiga territory. Still love Paradroid on the C64 though. And amazing amazing game.

[Herr Schatten]

Still love Paradroid on the C64 though. And amazing amazing game.

I agree with this. Paradroid is a stroke of genius.

[mr_m0nks]

would anyone know where i could find a scan of the Armalyte Instructions??

[Lloyd Mangram]

Here you go...

click!

[mr_m0nks]

Thanks!

[Guardians Knight]

oh just remembered, Raid Over Moscow, does that count as a shmup or a boarderliner?

oh and same goes for Blue Max while im looking down memory lane with my rosey goggles on, damn that was amazing. remember spending eons on that altho im sure it just kept on looping and couldnt actually be completed. mind i was about 8 when i used to play on it so perhaps my skills 20years on could allow me to complete the bugger assuming its possible. anyone know for sure?

[mr_m0nks]

Picked up this week on ebay the Thalamus Hits collection and Turrican

so with the hits2 i now own

Sanxion, Delta, Hunters moon, Armalyte and Retrograde

Just need to get a copy of R-Type (and katakis if i can track down a copy) for the ol beast and i think im sorted

[Herr Schatten]

Picked up this week on ebay the Thalamus Hits collection and Turrican

so with the hits2 i now own

Sanxion, Delta, Hunters moon, Armalyte and Retrograde

Just need to get a copy of R-Type (and katakis if i can track down a copy) for the ol beast and i think im sorted

You should also check out Catalypse. It's great.

[MadScientist]

You should also check out Catalypse. It's great.

Armalyte is overrated and Catalypse is great? I thought Catalypse was basically a simplistic Armalyte clone? Been a while since I played Catalypse though, so maybe I'll check it out again.

Vice or VicePlus is the best C64 emulator for Mac users. I use the cocoa version which does the job nicely.

Anybody played Metal Dust? Came out in 2005 (!). Looks very Manfred Trenz-y;

http://www.protovision-online.de/md/tra ... _small.mpg

[escadrille]

I was a dedicated Commodore fanboy as a kid, but at 28 that puts me firmly in Amiga territory. Still love Paradroid on the C64 though. And amazing amazing game.

I'm also 28, but I had a C64 until I finally got an NES. Always fantasized about getting an Amiga, but never did. I remember seeing pics of Loom and The Immortal and not understanding how it was possible that something that good-looking was a playable game.


Alcon on C64 was my first shmup.