deater

when making the Apple II version of Myst I more or less generated graphs like this by hand based on playing through the game (in order to hook up the data structures for the custom 6502-assembly language engine) I wonder if it would have been easier to automate it like this.

the IA is great for hosting demos too, including running in in-browser emulation. For example see: https://archive.org/details/@deater78

to any fans of TMBG I recommend the two-part AV Club article on them that was just posted a few days ago https://www.avclub.com/they-might-be-giants-interview-set-li...

it's funny how songs with ridiculous lyrics seem unbelievable (especially across generations) can turn out to be real. My father, whose name was Michael, would always sing the chorus from "Playground in my Mind" and we were convinced he was making it up.

Similarly if you ever get a chance you should read the Dave Barry book "Book of Bad Songs" where he relates singing "MacArthur Park" to his increasingly incredulous son.

having VBLANK available works wonders, see this double-hires code I just put together that only looks nice due to the magic of VBLANK on Apple IIe/IIgs (Apple IIc is much harder to get VBLANK from if you're playing music with interrupts) https://www.youtube.com/watch?v=1QwUGFDcQcI

I don't know if there's a good way to search for them. Most of the Lovebyte entries can be found on pouet or demozoo.org but I don't know if there's an easy way to filter out only Linux entries.

I've written a few sizecoded raspberry pi entries, there's even a writeup of one of them in tmp.out where I loaded some code into the ELF headers https://tmpout.sh/3/08.html

for those excited about tiny ELF executables, or tiny programs in general, check out the Lovebyte size-coding demoparty happening next weekend. It's likely there will be a few tiny ELF entries there.

do cloud providers give full, unrestricted access to hardware performance counters?

these days most distros lock down perf_event pretty tightly by default, making it fairly useless unless you have admin access to your machine

this is due to timing attacks you can do with detailed perf info, but also due to the constant stream of bugs found by the perf_fuzzer that took years to fix and it was easier to just lock down by default

if Sally Mckee, who coined the term "Memory Wall", had a nickel for each time it gets mentioned, she'd have a lot of nickels

it's interesting the 4c+ has a Yamaha variant of the chip, probably for the best.

Recent other Mockingboard replicas use AY-3-8193 which turn out to sound awful, especially when trying to play ZX-style chiptune/demoscene music

the idea was the original Apple II was made in 1977 as a game machine (Woz wanted to play breakout in software) but there really wasn't much of a concept of what a "Game Machine" was back then, it was mostly a huge hack trying to get minimal chipcount

years later when the c64 and IBM PC came out, the IIe was released which did have vblank support, but Apple II devs were reluctant to break backwards compatability.

You can still do a lot of cool games w/o vblank support. I'd say it'd barely makes the top 5 list of most annoying things about programming games on the Apple II.

And all these other "better" platforms, tell me do they have a port of Riven? http://deater.net/weave/vmwprod/riven/

it's more complex than that, I think IIe and IIgs have the same register but polarity reversed, the IIc has a weirder interface that generally involves setting up an interrupt through the mouse firmware

you can race the beam, I've written many demos that use this. On the original Apple II you have to do something called "vapor lock" or "reading the floating bus" where you draw a pattern to memory scanned by the video circuitry, then read an unmapped memory address and you get a "ghost" of the last value read by the video circuitry due to capacitance on the bus. You can then find the beam location, but from then on you have to cycle-count everything. Sather describes this in his book.

the discrete hardware part of the Apple II is fascinating window into 1970s hobbyist electronics sometimes. In the flashing text mode, you might think the flashing text (also used for the cursor) is done in software or something. But no, it's a 555 timer gating off the video signal for that particular character.

if you're excited about Apple II graphics, and also about the new Riven remake, but you don't have the VR hardware for Riven, you can try out the recently released Riven-for-Apple-II subset: http://deater.net/weave/vmwprod/riven/

I guess we'll all have to go back to using "linux_logo" for our sysinfo ansi-art needs, though that author seems to spend most of their time on the demoscene/video-game demakes these days.

no, you could very easily clone the Apple II easily and it was done many, many times

it's true that eventually Apple started suing people, but until Apple vs Franklin it was unclear if you could even copyright a BIOS. And once that was determined, people had to clean-room reverse engineer the BIOS but it was possible to make clones (see the Laser 128 and many many others)

this is just as open as the IBM PC was. You couldn't just drop a copy of the PC bios into your clone, you had to go to a 3rd-party reverse-engineered BIOS

I'm a bit curious about this part of the article:

> Unlike all of its major rivals—including the Apple II—the IBM PC was built > with an open architecture.

The Apple II, designed by Woz, is famously open, to the point the original model came with full schematics and ROM listings which made it trivially cloneable. I'm curious why this isn't considered an open architecture.

strange they seem unaware of the RR deterministic debugger work

especially as that builds off of the extensive work done on x86 counter determinism here: https://web.eece.maine.edu/~vweaver/projects/deterministic/

it turns out x86/amd chips many of the perf counter events are offset by the (unpredictable) interrupt count because the interrupt return instruction uop gets counted as both a user and kernel instruction. On many processors the retired store instruction avoids this issue.

it just seems a shame there are so many projects like this where people spend so much time making it, but then run yet another pong or snake on it. there are a lot of cool game concepts you can do on a 40x48 RGB grid, as shown by some recent 8-bit releases. Check out pico-8 and tic-80 for examples too. Having a multiply or divide instruction available is game changing

you should make it 40x48 and then you can run Apple II lo-res games on it like Myst or Another World

it pains me to have an ANSI animation called "MS-DOS Escape Sequences"

It's likely it's 3 bytes of BCD (binary coded decimal). It's a handy way of storing things like scores, especially on 6502 processors which have built-in BCD handling support.

My Apple II "Mode 7" demo relies heavily on a "table of squares" multiply alogorithm, though it's signed (vs unsigned) which is even more of a pain on 6502. https://www.youtube.com/watch?v=o8427JsfGwk

So many 16-bit demo effects assume you have a decently fast multiply or divide instruction, which makes it really hard to do the same effects on 6502 (as I found with the second reality remake)

yes, some people ask why I rushed this out the door rather than finishing it later and releasing at some other party. But I really wanted to support Demosplash, and as a US scener I try to release something nice there each year.

I really would have liked to be there in person this year but things came up. November is awkward timing for me, both with the college schedule but also because it often overlaps with the big Supercomputing Conference that happens around the same time.

And as why not release at a European demoparty: most of the crowd there don't really appreciate/understand the Apple II limitations, but also with Covid over they expect you to show up in person and bring along working hardware (sourcing a local Apple II, especially an NTSC one with a compatible power supply would be a challenge).

It's a fake BIOS/DOS bootscreen to parody the startup of the original DOS demo (the c64 version of the demo does something similar).

It says DOS3.3 as a joke, because Apple DOS3.3 was a real, long-running operating system for the Apple II that predates MSDOS.

The actual demo runs no operating system at all, it's a custom bootsector designed by qkumba that can load arbitrary tracks off of a raw Disk][ floppy and is much faster than DOS3.3 or ProDOS and also requires very little memory overhead.

I do plan to release a "final" version that improves a bit in places. There's no video of it yet but if you view the in-browser-emulator at archive.org you can see disk2 the full length 3d-flying sequence is finished (the party version cuts out about 2/3 the way though).

The challenges of trying to be on the demoscene while holding down a full-time job ;)

some more of the effects (or better attempts at them) should be possible. The tunnel, the bouncing dots, the bounce effect with the polar bear image. A lot got thrown together at the extreme last minute to hit the Demosplash deadline.

Second Reality for Apple II!!!! http://deater.net/weave/vmwprod/second/