[C64 - A reappraisal 2017]

Everyone wants to know why the 800 didn't have proper slots and that's pretty much the reason. Atari sold their products through consumer channels and they wanted to target the living room. This meant the 800 was a beast made of cast aluminum with shields on every removable surface. Exposed slots would never have passed, or would have added a lot of cost to make sure they couldn't leak. Then (thanks to the TI fiasco), the FCC relaxed their standards and computers could suddenly be sold wrapped in foil-lined cardboard.

 

Bill, do you know how to get hold of the FCC standards from that time?

[C64 - A reappraisal 2017]

How is it they were able to sell so many to home users?

Anyone can buy and bring home business machines. They just aren't guaranteed not to cause interference, and they cannot be designed to connect to the TV. I'm sure that people who bought the aftermarket modulator for the Apple had noisy picture issues.

 

I'd love to know what the FCC docs from the late '70s say. There were probably other restrictions on how they were sold and marketed as well.

[C64 - A reappraisal 2017]

 

"C64 reliability was all about the VIC chip and a couple of other custom chips. In the early days even the best ones sparkled (so we changed the Kernal so the unused character cells on the blue screen had the foreground and background characters set to the same color, they still sparkled but it was the same color as the background)

I got there just as they were going to a Beryllium lead fram to help pump the heat out of the die."

 

This is one of the problems with NMOS technology. The power consumption is high and goes up with the number and speed of switching transistors. Atari's video was spread over 2 chips and most of the internals (everything not dealing with high-rez output) are switching at 3.58MHz. Vic II is one chip internally running at about 8MHz. That's asking a lot in a passively cooled plastic DIP package.

[C64 - A reappraisal 2017]

Also remember that Apple didn't get their machines FCC certified for home use. This is how they got away with exposed ribbon cables. Everyone else had to devise a low-emission interface, and serial was it.

[C64 - A reappraisal 2017]

As far as speed, The Apple II disk was/is the fastest among the home micros. An entire disk of 143K can be read to memory in something like 14 seconds.

 

The Apple drive card was very fast because it basically piped the raw drive signals to the computer's CPU.

 

The downside was that without a traditional controller to shift in the data, the CPU was pretty much completely utilized during loading and the drives cables had to be fairly short for the drives to work reliably. It was a much cheaper solution than a dedicated microprocessor to serially feed the host machine, though.

[C64 - A reappraisal 2017]

That may be, but the central electronic repair center was chock full of c64's. Cooked chips, cooked power supplies. Very rare to see an Apple or Atari on the sheets. Atari made a number of power supplies, word got out quick which one not to have. You could trade you ingot in at most users groups for a nominal sum.

 

I don't remember the ingot being a problem back in the user group days. I thought it became an issue much later.

 

Everything I heard about bad C64's was that in the early days many were bad from the box, so the issues got sorted before people started using them.

[C64 - A reappraisal 2017]

Also, if a sound chip made years before SID can play a sawtooth, then isn't SID emulating Pokey?

[C64 - A reappraisal 2017]

Erm... POKEY CAN emulate SID. It just doesn't sound muffled...

Emulate is a strong word. It basically implies something can be used in place of another thing. Pokey can't emulate SID. Pokey can make some of the same sounds as SID. SID can make some of the same sounds as Pokey. Playing a sawtooth is not emulation.

[C64 - A reappraisal 2017]

of course POKEY can emulate SID no problem...

I'm not sure I'd say Pokey can emulate SID. The CPU is doing most of the work. So, the A8 can emulate SID.

[C64 - A reappraisal 2017]

Yes, I'd say that overall, the SID was probably the best overall stock sound chip, all things considered (versatility, actual usage, etc.), until the Amiga. The POKEY was definitely right up there, however. If it makes someone feel better to put the POKEY 1 and the SID 2, so be it. The point is, neither are without well-known flaws, but both are superior sound chips, especially compared to their contemporaries.

 

As awesome as Pokey is, it's taken decades to figure out because it's main features are pretty basic, and then there's a bunch of neat things it'll do if you start trying everything.

 

SID presented you with most of its tricks right up front. It was just a matter of applying your music skills.

 

So even if you prefer Pokey, you have to realize that most programmers wouldn't have had the time to do more than the documentation suggested.

 

And yes, they are both great sound chips.

[C64 - A reappraisal 2017]

I've always had a question about the 6809 mod. According to the datasheets, there's a limit on how long you can halt the 6809 (probably due to dynamic cells) and a text badline exceeds that spec. Did I calculate something wrong or is just working anyway?

[Altirra 3.00 released]

I'd like to make a suggestion for the Hardware Manual regarding the Antic NMI bug (p. 56, Note 15).

 

I don't believe this to be specifically an error on Atari's part. The earliest MOS manuals (MOS 1975, Synertek 1976) for the 6500 series state that NMI needs to be 2 cycles long and Antic's NMI is 2 cycles long. However, this is not sufficient when the 6502 is processing an IRQ and represents either a 6502 bug (that is, the designers thought 2 cycles was sufficient) or a documentation bug (that is, the datasheet author put in wrong information). Because the Antic spec complies with MOS's documentation, I suggest that this is a CPU/MOS bug more than an Antic one.

 

What would make this an Antic bug is if the NMI's rise or fall was out of spec (which I don't know).

 

The text is as follows:

Page 38, Section 1.4.1.2.9, Paragraph 2.

 

"The NMI signal must be low for at least two clock cycles for the interrupt to be recognized, whereupon new program count vectors are fetched."

 

Later datasheets seem to be less detailed and don't give a minimum spec. I think it is usually assumed the program will reset the NMI hardware manually in the service routine. Since NMI's on the Atari occur at spaced intervals (400/800 reset is an exception), Atari decided to make them clear themselves according to the 2 cycle spec since they cannot happen back to back.

[C64 - A reappraisal 2017]

Also, even though people discount the Atari's ~1.8MHz clock due to the 50% or so DMA losses during the screen, you have to remember that it was almost twice as a fast other 6502 machines during the blank which is arguably the best place to have it.

[C64 - A reappraisal 2017]

To me, the best A8 games are the ones with graphics suited to the capabilities of the system. Things like Fort Apocalypse and Shadow World have a good high-contrast look. I know that with that big color palette it's tempting to waste all your colors on shading, but many of the later games just look too bland and monochrome because they tried to use extensive shading on everything.

[C64 - A reappraisal 2017]

The A8's cartridge port is limited to 16K without banking.

[C64 - A reappraisal 2017]

The C64 scene in the US is anemic compared to the Atari 8 bit, a reversal of the way things were in the old days, Lemon64 is the main C64 enthusiast site, and the forum is not nearly as lively and filled with projects as this one.

Interesting. I based that on the rather ambitious WIP game projects I see on YouTube.

[C64 - A reappraisal 2017]

For me, the 8-bit era is the A8 and the C64. They were machines built from custom silicon no one else had.

 

Spectrum and Amstrad didn't exist here. The Apple II was important but just so limited unless you were using it in a home business. Stuff on the Coco was always so ugly. People forget that a smooth full-screen scrolling game was only possible on a few machines. How many machines could do Blue Max? How many machines could play multi-voice music over a game? Just because a platform has a vast library doesn't mean there's much variety in the style of the games.

[Sex Pong. Clickbait Maybe?]

Something that I think is missing in all this is just because things were happening that look bad on paper doesn't mean the women involved weren't also a part of that scene. If Atari grew out of a free love, hook-up culture, then how the women viewed the environment is as important as what happened.

 

In other words, we've always looked back at things like Woodstock and seen men and women participating in drugs and sex equally. Today we're more likely to call it a giant sea of female victims. Which is it?

 

I'm going to cover my bases and mention that I always believe you have to be respectful when someone declines, but a sexually charged atmosphere isn't necessarily a predatory one and it seems like the women at Atari had their power as well.

[C64 - A reappraisal 2017]

Read one of the designer's bluntly honest interviews where he talked about how much they cut out of the C64 to minimize costs. IIRC $134 in parts at the initial $600 price. Simple is good in many ways but they took it to a new extreme. IIRC Basic 4.0 was available but they had a bunch of 2.0 in stock so they threw those in. Stuff like that but a lot more of head scratching moments. Can't find the interview now but it's very enlightening. After reading it I was thinking... OMGWTFBBQ.

 

At the time ('84-'86) did not like it for many valid reasons. In retrospect I judged it too early. The C64 hit its prime later, after the Amiga was already out.

 

That's one reason the C64 is kind of a love/hate thing with me. Everything about the 400/800 needed was about quality. The construction was solid, the expansion methods were elegant, it had unmatched graphics and sound capabilities, the OS was robust. Unlike other PCs of the day, this one was being made to be friendly for non-techie types while still costing less than many of the options out there.

 

Commodore recognized that many households were holding off getting a computer because of the cost and that bringing the price down was more important than a premium system. Revamping their budget machine with the new chips and 64K of RAM (which is what really got people's attention before they knew what the chips could do) is what did the trick. There was a wave of enthusiasm for that machine like the industry hadn't seen before.

[C64 - A reappraisal 2017]

I'm not sure from your reply if you're following what I meant, but...

 

You're right. I follow both scenes, and the Atari 8-bit developers, especially hardware, are far more active than the C64 developers are.

 

What I meant was that the C64 is a great games machine even though I hate to admit it. I always figured the C64 scene was bigger.

[C64 - A reappraisal 2017]

Despite the C64's shortcomings (and all the years I hated it for the stuff it got that I didn't), it's got it where it counts.

[New Atari Console that Ataribox?]

Oregon and Idaho are now combined into one big state!

Oh, that's Idagon.

[WARLORDS! Legal way to get around Atari @ names!]

#1 fact of IP law.

 

A party does not need to be right. A party only needs enough money to bleed the other party dry.

[Found this in an 800 OS card]

It appears to drive Pin 20, which looks unused in the schematic. I'm guessing it's an address decoder for some other device.

[C64 - A reappraisal 2017]

i tried the A8 first and struggled with it so the C64 seemed easier to me personally, and for the kind of things i prefer coding the C64 is easier overall. But mileage varies depending on what y'want to write, really.

 

IMO both these machines are very easy to program for as long as you're painting by numbers. A program that draws a simple background and has a few moving objects and sound effects probably won't take much time at all. They become difficult when you want to write something more than a magazine game and you have to start doing things on the fly instead of once per frame.