AndyR

You got... tired of the music? (Edit: just realized this was a necro'd thread, so comment aimed generally and not at the OP) This game's soundtrack[1] is absolutely groundbreaking, it's one of, like, the top five or six most important defining moments in home computer audio. I will occasionally boot the game and let the demo run behind me (it cycles between all the tracks) as background music. Though I guess we should be grateful the Atari even has the music, Origin dropped it (!) for Ultima IV. [1] FWIW: originally written and best expressed on a Mockingboard, though the Atari variant is pretty good translation. Oddly despite the SID's capabilities, the C64 port is sort of a pingy mess.

I won't try to guess at exactly what the effects of a bad 12V rail would be. But, is there an end to this story you're imagining that doesn't involve fixing your power supply? If you know it's broke, it's broke. Fix it. Seems like if you really want to know, get a bench power supply (or just an ATX box from an old PC) cabled to the board instead and see if that fixes the video issue.

I'm in the process of getting a 400 set up, and while I had the board out on a bench I managed to break the lid switch trying to clamp it closed. Unfortunately it's the spring strip that snapped, so repair isn't going to be possible. Obviously one solution would be to just remove it and bridge the connection to be always on, but I'm sort of a purist. Does anyone know if this is a standard part that can still be sourced, or if there are replacements available somewhere, or if something modern works compatibly enough?

I have one of these, got it from the early 2000's from an Atari fan (long since lost his contact information) in Gilroy, CA who was cleaning out his garage. Really these are just 810's, electronically. Apparently the store got hold of a surplus batch of 810 analog/logic/power boards, which they paired with new Tandon mechanisms (themselves dirt cheap as the IBM PC world was rapidly moving to half height mechanisms) and sold in their own no-frills folded metal enclosure. I have no idea if they had a license from Atari for the copyrighted ROMs, but the one I got absolutely had an Atari ROM in it. (Per an advertisement I found, these were also available with Happy kits, I think.) Mine works fine still, but there's nothing behaviorally notable about it. It's just an 810.

I'm getting back into this world after a decade or so, and am in the process of trying to get a stack of drives working that haven't been touched since the 90's. In fact straightforward cleaning and lubrication has recovered almost all of them[1]. But I have one 810 (MPI, not Tandon) that is missing its faceplate. The drive otherwise works great though, so I'm hoping there's some kind of restoration option here. Does anyone collect and sell these? I found someone on eBay with Tandon plates, so I guess there's hope. Are there 3D printable replicas anywhere? Does someone have an equivalent stack of dead drives and want to arrange a part swap? [1] With a few permanent casualties: one broken Tandon door latch, one drive head assembly was so stuck to the rails that I broke an arm off trying to release it, one Percom drive had a dead logic board so I pulled out the factory-standard drive mechanism to use with a Greaseweazle.

I'll try to reinstate it in my folders, I also screwed up the torrent when I moved the files. I'll let you all know. I just put my copy back up, with a 100kB/s cap. Should be up for a few days at least.

Maybe I'm misunderstanding (I don't know jack about the CoCo), but that sounds just like a "DDR" version of the architecture of the Apple and Commodore, with the CPU and Graphics sharing the memory in strict alternation. The limit there is DRAM speed, not really clock or bus design. If you have and are willing to pay for DRAM that will cycle at 3-4MHz you can do it, if not, it's not an option. It wasn't in the late 70's -- fast refresh DRAM was being sucked up for devices like the VAX 11/780 (which ran the interleaved memory bus at 5 MHz, with a wait state for sequential accesses to the same bank, IIRC) and was extremely expensive.

OK, here's the disconnect right here. You're thinking about a product comparison made in 1983, when Apple was the established market leader that had been passed technologically by its competitors but was still commanding premium prices. I was an Atari user at the same time, and felt the same way (to be fair, I was twelve). But what I'm talking about is the computer released in 1977, which was cheaper, cleaner, and better than any of its competitors by an enormous margin. S-100 boxes were clunky hobbyist things. S-100 video output was a joke. S-100 audio didn't exist as such. The TRS-80 and PET were similarly limited to being straightforward packagings of the existing features for non-hobbyists. The Apple, on the other hand, had actual graphics, in color even. It had sound. It had a built-in BASIC interpreter. It used 16k DRAMs and could expand to 48k right on the board as-shipped. It had an expansion bus that actually made sense. It has a built-in monitor with assembler. The Apple II in 1977 defined the features that we'd come to expect in home computers over the coming years. That later computers did the same stuff better or more cheaply isn't, to me, very interesting; of course they did, because if they didn't then they would simply have failed. But someone had to make those first leaps -- either doing something new or integrating something in a new way, or making something cheap enough to live in a new market space -- and the Apple II took a whole lot more of those jumps than other platforms did. That's really my point. If you want to write the history of 8 bit computing, an awful lot of the most important stuff happened in Woz's lab.

And similarly, Atari came up with one of the dozen or so audio synthesizer ASICs floating around in the late 70's based on divided square wave counters and LFSRs. Pokey was undeniably more capable than the Apple II circuit, but it certainly wasn't more innovative. Again, it's about aesthetics. I'm trying to explain to you why I find the Apple design beautiful, I'm not trying to get into a pissing contest about whose pl@+form was teh R0xor. Just as you view the Apple design as a simple device unworthy of praise, I feel the same way about Pokey: Pokey is exactly the chip you'd expect Atari to have designed, given their market position and engineering focus. It's a fine chip, and among 8 bit home computers it was king for several years, at least until the SID came out and introduced new features to the market. But in the broader world of music synthesizers or arcade chipsets it was only one among many, and not terribly distinguished. And FWIW, I'd argue that the 6502 itself was distinguished mostly by its price, not capability. The 8080 and 6800 were "thicker" and overall clunkier parts, but worked fine as CPUs. Had Motorola in particular been more responsive to its engineers and more agressive in pricing, MOS might never have spun off.

Even that has to be subject to some qualification as to what "junk" means. The Apple II "stock sound" hardware was a tiny bit of address decode logic and an amplifier for the speaker line. Pokey sounds better because it's a purpose-designed ASIC for video games with a thousand transistors or so. But before Apple shipped it, no one in the broader world had ever heard of PWM, nor thought it would be useful for anything but the simplest beeps. But within a few years, Nazi's were stepping around Castle Wolfenstein screen shouting intelligible "Achtungs!" at us. All with a tiny handful of transistors and a cheap speaker. The Atari solution was clearly better, technically. But it was more expensive and elaborate, and much less constrained. In hindsight, it's not surprising that Pokey worked; lots of other synthesizer chips out there did similar things. It is surprising that Woz made sound work on the Apple as well as it did. So my vote goes to Woz on this one. The aesthetic comparison needs to be informed by context. I mean, if you're just talking about which hardware has the "best sound", then the telephone in your pocket is going to win hands down anyway.

Not sure how to interpret this, so I'll just ignore it. If you'd prefer I not be here, just say so. Indeed, which explains why I'm not, y'know, jealous of the Apple II's graphics capabilities. The whole point of this thread is aethetics -- what do you like vs. not like about different devices. I'm a huge admirer of the Apple, and I haven't hid that fact. That by itself shouldn't be a reason for you to get your feelings hurt and feel you have to "defend" a 30-year old platform. I like the Atari too, I promise.

Really? Do you know which titled used this trick? The problem with this is that there's very little time available in that interrupt. If you take too long, you'll miss the next clock edge in your I/O polling loop and drop a bit. The C64 architecture already has frustratingly non-deterministic interrupt timings (the VIC-II needs to pull sprite data and can lock the bus for dozens of cycles to do it), and that problem is why the 1541's serial speed was so slow to begin with.

An LFSR maybe? Might make sense for a simple dongle, as it's easy to simulate in software (clock in a few random bits, check the output against the software version) but still reasonably non-trivial to replace for a prospective copier. Probably about as good hardware protection as you can get on an 6502. These boxes certainly won't be doing RSA.

No, the Commodore serial bus was bit-banged in software, not interrupt driven. So the CPU had to be constantly polling while the data was being delivered. I'm not 100% this was a hardware issue, actually (the C64 actually did have a working shift register and didn't technically have to poll, IIRC). But I'm not aware of anyone that managed to make it work. It had the same problem the Apple did. The Atari SIO bus, however, was interrupt driven and you could, in fact, do stuff while the disk was working. This was pioneered AFAIK by the Lucasfilm folks c. 1985, whose games would play music and animation while loading. The Ballblazer loader was especially cool. By way of aesthetic argument, though, I'm still not sold. Requiring that the drive be an intelligent microcomputer just to play some nice load-time animations seems to be a poor tradeoff. Given the part manifest involved, if I were an Apple user I'd probably have preferred just having the second computer.

Ah, very cool. I'm not sure where you're taking offense here. My point wasn't to judge your (or anyone else's) reasoning about how the design worked, just to point out that you chose not to put it in the cartridge port. Which you didn't. So modulo an incorrect guess about design choices (I thought market pressure to support older machines, when you actually chose simplicity of implementation) I think we agree, no? Except it is, sorta. The original question was why didn't the Atari cartridge port see use in the same application space as the Commodore one. I'm certainly not trying to start a flame war. But certainly one answer to why the cartridge port was underused was, in fact, that it wasn't a general purpose expansion bus when, in fact, Commodore's was.