7 ms·

Show HN: Cross-Platform Apple IIe Emulator Written in Go

103 points by empressplay 10y ago

empressplay 10y ago
Currently the Octalyzer features full-screen Apple IIe emulation with decent compatibility, USB and mouse-controlled joystick support, cloud disk library (when logged-in to Octa-Link), 3D camera support, 3D LOGO, enhanced BASIC interpreters, custom file browser and editor, and remote screen sharing.
- Hydraulix989 10y ago
  Does it have a CRT filter? A lot of these retro games don't look so authentic on LCD screens because things like blur and shadow masking were actually used by the designers of the original games. http://filthypants.blogspot.com/2015/04/more-crt-shaders.html http://filthypants.blogspot.com/2015/04/more-crt-shaders.htm...
  - empressplay 10y ago
    Thanks for the link! We don't currently (although there is some rasterisation provided by the OpenGL rendering) but we'll look into some CRT shaders =)
  - lloeki 10y ago
    I could care less about games looking like they're "authentic" WRT to curvature or phosphor grid pattern, but things like aspect-ratio correction (non-square pixels), colour switching[0], or cheap transparency tricks through composite[1] are another matter entirely. [0]: http://www.aaronbell.com/secret-colours-of-the-commodore-64/ http://www.aaronbell.com/secret-colours-of-the-commodore-64/ [1]: http://nerdlypleasures.blogspot.fr/2015/03/the-case-for-composite.html http://nerdlypleasures.blogspot.fr/2015/03/the-case-for-comp...
haspok 10y ago
Auto updating? You must be joking. Also, a single binary file download without even a checksum (let alone the source)??? No thank you.
- coldtea 10y ago
  You don't have an application firewall and restricted user rights? Or a VM to run this in?
  - josefx 10y ago
    Implying that both of these have been exploit free? - posted from my totally secure Firefox
meggyMasters 10y ago
example
yobert 10y ago
So cool. I'd love to read the source if it's available?
loppers92 10y ago
That is awesome
giovannibajo1 10y ago
I've been working on and off on a Nintendo DS emulator 100% written in Go. You can have a look here: https://github.com/rasky/ndsemu/ https://github.com/rasky/ndsemu/ It features both the 2D and the 3D engine (with a full software rasterizer with poly-fillers generated through go generate). It's highly concurrent (each graphic layer is drawn in a different goroutine and then mixed together). The ARM interpreter is also generated via go generate. I'll add some screenshots at some point.
- mappu 10y ago
  I think Go has great potential in this area. Some emulators (? PCSX2/Dolphin/...) are famously stuck with very few threads owing to the design of the underlying hardware, so anything that encourages extracting parallelism from within each subsystem could potentially be a major performance win.
  - flohofwoe 10y ago
    Cycle-perfect emulators at least for typical 8- and 16-bit systems need to run each emulator subsystem (CPU, video, audio, ...) in lock-step for each clock cycle. Spreading those emulator systems over multiple threads would mean that the threads need to synchronize with each other after each step (which is just a few host CPU instructions long). It might be easier for more modern hardware where subsystems are much more decoupled from each other (and I guess with Moore's Law dead this is our only hope to emulate more modern hardware in the future).
    - giovannibajo1 10y ago
      That's true. In the case of Nintendo DS, I'm aligning doing line-based emulation; so I first serially emulate the two CPUs (I could in theory parallelize then, but I haven't properly design the emulator around this, so all memory-mapped callbacks are not concurrent safe), and then emulate the graphic subsystem for a single line, spreading the different layers across different goroutines. This means that goroutines synchronize 263*60 times per second, which is something. I measure a high contention, so I'm not even sure it was worth in the end, but I thought it was a good experiment to attempt :) Another Go-related thing I did was using struct tags to configure memory-mapped registers in a declarative way. See for instance: https://github.com/rasky/ndsemu/blob/master/irq.go#L13 https://github.com/rasky/ndsemu/blob/master/irq.go#L13 where I configure the memory-mapped registers of the interrupt controller; "wcb" / "rcb" tags stand for write/read callbacks, which means that specific callbacks (with names matching the register names) will be called for each read/write operation; this is all achieved through reflection. The same applies to mapping the whole register bank, which is done here: https://github.com/rasky/ndsemu/blob/master/nds9.go#L69 https://github.com/rasky/ndsemu/blob/master/nds9.go#L69 The memory subsystem handling these and more features is in emu/hwio, and I'm actually pretty proud of it. For the memory mapping itself, a radix tree is built which is quite quick to lookup and doesn't require much barcoding. In fact, the whole "emu" package is a generic framework for emulators in Go, and I plan to reuse it in the future :)
jlebrech 10y ago
Go is the new C
- meggyMasters 10y ago
  > Go is the new C example
  - pjmlp 10y ago
    "Booting into Go bare bones" http://wiki.osdev.org/Go_Bare_Bones http://wiki.osdev.org/Go_Bare_Bones "Novm Is A KVM-Based Linux Hypervisor Written In Go" https://www.phoronix.com/scan.php?page=news_item&px=MTg4MzA https://www.phoronix.com/scan.php?page=news_item&px=MTg4MzA "A network stack written in pure Go" https://github.com/unigornel/go-tcpip https://github.com/unigornel/go-tcpip Surely there are other similar projects around the web.
    - sigjuice 10y ago
      These do not look like very credible examples. According to NoVM's GitHub page, it has not been updated in two years. go-tcpip does not actually have a TCP implementation.
      - pjmlp 10y ago
        If you pointed out similar examples about C in the 80's, I would provide a similar reply, after all any serious programmer targeting the home market would use professional tools like Assembly. One needs to start somewhere, but apparently to impress HN one needs to hide in some cave and present a done product after some years hiding, as the fashion driven industry has lost most visionaries.
- afdsadf 10y ago
  C is the new C. Go is only going to replace C like Java was going to replace C.
  - 10y ago
z3t4 10y ago
One of the screen-shots looks like Flappy bird: http://octalyzer.com/wp-content/uploads/2017/02/oct16.png http://octalyzer.com/wp-content/uploads/2017/02/oct16.png
- empressplay 10y ago
  It's flapple bird:)
notthemessiah 10y ago
Reminds me of the AppleII+ simulation from XScreensavers: https://www.youtube.com/watch?v=p3QZqhp67l8 https://www.youtube.com/watch?v=p3QZqhp67l8 http://manpages.ubuntu.com/manpages/trusty/man6/apple2.6x.html http://manpages.ubuntu.com/manpages/trusty/man6/apple2.6x.ht...
tombert 10y ago
An emulator has been my "bucket-list" ever since I became a software engineer. I still haven't done it...Do you have any good pointers for someone to get started with making an emulator (particularly for someone who works almost exclusively with with server-ey stuff)?
- girvo 10y ago
  Definitely look into CHIP-8, it's more of a virtual machine than an emulator, but then what's the difference at the edges!
harel 10y ago
I'm afraid this does not appear to work on my system (Ubuntu 16.04, 64bit). None of the key combos work (Shift-ctrl-` etc.), and dropping an image just crashes it. And I was all geared up for karateka...
- empressplay 10y ago
  We will check it out thanks!

103 points by empressplay 10y ago

Currently the Octalyzer features full-screen Apple IIe emulation with decent compatibility, USB and mouse-controlled joystick support, cloud disk library (when logged-in to Octa-Link), 3D camera support, 3D LOGO, enhanced BASIC interpreters, custom file browser and editor, and remote screen sharing.

Hydraulix989 10y ago
Does it have a CRT filter? A lot of these retro games don't look so authentic on LCD screens because things like blur and shadow masking were actually used by the designers of the original games. http://filthypants.blogspot.com/2015/04/more-crt-shaders.html http://filthypants.blogspot.com/2015/04/more-crt-shaders.htm...
- empressplay 10y ago
  Thanks for the link! We don't currently (although there is some rasterisation provided by the OpenGL rendering) but we'll look into some CRT shaders =)
- lloeki 10y ago
  I could care less about games looking like they're "authentic" WRT to curvature or phosphor grid pattern, but things like aspect-ratio correction (non-square pixels), colour switching[0], or cheap transparency tricks through composite[1] are another matter entirely. [0]: http://www.aaronbell.com/secret-colours-of-the-commodore-64/ http://www.aaronbell.com/secret-colours-of-the-commodore-64/ [1]: http://nerdlypleasures.blogspot.fr/2015/03/the-case-for-composite.html http://nerdlypleasures.blogspot.fr/2015/03/the-case-for-comp...

haspok 10y ago

Auto updating? You must be joking. Also, a single binary file download without even a checksum (let alone the source)??? No thank you.

coldtea 10y ago
You don't have an application firewall and restricted user rights? Or a VM to run this in?
- josefx 10y ago
  Implying that both of these have been exploit free? - posted from my totally secure Firefox

meggyMasters 10y ago

example

yobert 10y ago

So cool. I'd love to read the source if it's available?

loppers92 10y ago

That is awesome

giovannibajo1 10y ago

I've been working on and off on a Nintendo DS emulator 100% written in Go. You can have a look here: https://github.com/rasky/ndsemu/ https://github.com/rasky/ndsemu/ It features both the 2D and the 3D engine (with a full software rasterizer with poly-fillers generated through go generate). It's highly concurrent (each graphic layer is drawn in a different goroutine and then mixed together). The ARM interpreter is also generated via go generate. I'll add some screenshots at some point.

mappu 10y ago
I think Go has great potential in this area. Some emulators (? PCSX2/Dolphin/...) are famously stuck with very few threads owing to the design of the underlying hardware, so anything that encourages extracting parallelism from within each subsystem could potentially be a major performance win.
- flohofwoe 10y ago
  Cycle-perfect emulators at least for typical 8- and 16-bit systems need to run each emulator subsystem (CPU, video, audio, ...) in lock-step for each clock cycle. Spreading those emulator systems over multiple threads would mean that the threads need to synchronize with each other after each step (which is just a few host CPU instructions long). It might be easier for more modern hardware where subsystems are much more decoupled from each other (and I guess with Moore's Law dead this is our only hope to emulate more modern hardware in the future).
  - giovannibajo1 10y ago
    That's true. In the case of Nintendo DS, I'm aligning doing line-based emulation; so I first serially emulate the two CPUs (I could in theory parallelize then, but I haven't properly design the emulator around this, so all memory-mapped callbacks are not concurrent safe), and then emulate the graphic subsystem for a single line, spreading the different layers across different goroutines. This means that goroutines synchronize 263*60 times per second, which is something. I measure a high contention, so I'm not even sure it was worth in the end, but I thought it was a good experiment to attempt :) Another Go-related thing I did was using struct tags to configure memory-mapped registers in a declarative way. See for instance: https://github.com/rasky/ndsemu/blob/master/irq.go#L13 https://github.com/rasky/ndsemu/blob/master/irq.go#L13 where I configure the memory-mapped registers of the interrupt controller; "wcb" / "rcb" tags stand for write/read callbacks, which means that specific callbacks (with names matching the register names) will be called for each read/write operation; this is all achieved through reflection. The same applies to mapping the whole register bank, which is done here: https://github.com/rasky/ndsemu/blob/master/nds9.go#L69 https://github.com/rasky/ndsemu/blob/master/nds9.go#L69 The memory subsystem handling these and more features is in emu/hwio, and I'm actually pretty proud of it. For the memory mapping itself, a radix tree is built which is quite quick to lookup and doesn't require much barcoding. In fact, the whole "emu" package is a generic framework for emulators in Go, and I plan to reuse it in the future :)

jlebrech 10y ago

Go is the new C

meggyMasters 10y ago
> Go is the new C example
- pjmlp 10y ago
  "Booting into Go bare bones" http://wiki.osdev.org/Go_Bare_Bones http://wiki.osdev.org/Go_Bare_Bones "Novm Is A KVM-Based Linux Hypervisor Written In Go" https://www.phoronix.com/scan.php?page=news_item&px=MTg4MzA https://www.phoronix.com/scan.php?page=news_item&px=MTg4MzA "A network stack written in pure Go" https://github.com/unigornel/go-tcpip https://github.com/unigornel/go-tcpip Surely there are other similar projects around the web.
  - sigjuice 10y ago
    These do not look like very credible examples. According to NoVM's GitHub page, it has not been updated in two years. go-tcpip does not actually have a TCP implementation.
    - pjmlp 10y ago
      If you pointed out similar examples about C in the 80's, I would provide a similar reply, after all any serious programmer targeting the home market would use professional tools like Assembly. One needs to start somewhere, but apparently to impress HN one needs to hide in some cave and present a done product after some years hiding, as the fashion driven industry has lost most visionaries.
afdsadf 10y ago
C is the new C. Go is only going to replace C like Java was going to replace C.
- 10y ago

z3t4 10y ago

One of the screen-shots looks like Flappy bird: http://octalyzer.com/wp-content/uploads/2017/02/oct16.png http://octalyzer.com/wp-content/uploads/2017/02/oct16.png

empressplay 10y ago
It's flapple bird:)

notthemessiah 10y ago

Reminds me of the AppleII+ simulation from XScreensavers: https://www.youtube.com/watch?v=p3QZqhp67l8 https://www.youtube.com/watch?v=p3QZqhp67l8 http://manpages.ubuntu.com/manpages/trusty/man6/apple2.6x.html http://manpages.ubuntu.com/manpages/trusty/man6/apple2.6x.ht...

tombert 10y ago

An emulator has been my "bucket-list" ever since I became a software engineer. I still haven't done it...Do you have any good pointers for someone to get started with making an emulator (particularly for someone who works almost exclusively with with server-ey stuff)?

girvo 10y ago
Definitely look into CHIP-8, it's more of a virtual machine than an emulator, but then what's the difference at the edges!

harel 10y ago

I'm afraid this does not appear to work on my system (Ubuntu 16.04, 64bit). None of the key combos work (Shift-ctrl-` etc.), and dropping an image just crashes it. And I was all geared up for karateka...

empressplay 10y ago
We will check it out thanks!