AppleSqueezer GS Turbo
Today, I'm really happy to announce a brand new AppleSqueezer accelerator: the AppleSqueezer GS Turbo. And as you may well guess from its name, the main difference is in the speed, although it's not limited to that. It comes with quite a few other improvements as well! While the existing AppleSqueezer GS v2 is already significantly faster than an Apple IIGS, at around 15 MHz, compared to the stock IIGS speed of 2.8 MHz, this time I tried to aim higher. Quite significantly. I basically felt that I needed to squeeze the IIGS with more force.
The 65C816 bottleneck
The AppleSqueezer GS v1 and v2 have a real physical 65C816 on board, and the clock frequency of this is limited to, officially - according to the datasheet - 14 MHz. It's already a bit overclocked on the AppleSqueezer, but overclocking it a lot more would risk making it unreliable, and would only marginally improve speed, if at all. Given that, I had to look into a different direction.
Squeezing more juice out of the Apple IIGS, get ready for 48 MHz!
In order to reach even higher speeds, while at the same time remaining super reliable, I created a brand new 65C816 core from scratch, running on a more powerful FPGA that is fitted on this new AppleSqueezer. It reproduces the exact instruction behaviour and cycle timing of the original processor, making it cycle accurate to the real 65C816: it was tested against about 5 million test vectors (10,000 emulation-mode and 10,000 native-mode tests for every opcode), plus real software such as GS/OS, Doom and Out Of This World. The core is fully implemented in hardware, but the difference from the physical 65C816 chip is that it can run quite a bit faster: 48 MHz. So, with the new AppleSqueezer GS Turbo, the CPU in your IIGS runs about 17 times faster than a stock GS setup, and at least 3 times faster than the fastest TWGS, ZipGS, or previous AppleSqueezer GS. This is some serious speed. To put this into perspective, at 48 MHz with zero-wait-state RAM execution, this new 65C816 setup gives you CPU processing throughput that compares well to some of the 68030-based Macintoshes of the time, such as the IIci, or even IIfx for certain workloads: it's wicked fast 😀
Ensoniq DOC audio integration, in stereo!
HDMI video output was already a feature in the AppleSqueezer GS v2. With the new AppleSqueezer GS Turbo, the HDMI output now also includes audio! The Ensoniq DOC chip has been implemented inside the FPGA, so you get clean, digitally rendered, accurate sound, in full stereo. This works fully independently of the DOC inside the IIGS. This was requested by quite a few users, so I think it should be a really nice addition to the new AppleSqueezer GS Turbo, and I was happy to be able to add it in! (it was quite a squeeze, to be honest!)
Other improvements
The new AppleSqueezer GS Turbo doesn't just have a faster CPU, it also comes with other improvements, such as:
Faster startup (the time from flipping the switch to the first display)
More data read from its built-in DDR3 RAM as opposed to the slower IIGS RAM (further increasing general performance)
More reliable updates with the help of a Golden core, made possible by a larger flash memory, which is now 4MB rather than 1MB. This golden core stays in flash while updating, and acts as a fall-back in case the upgrade fails. I actually haven't heard many issues with users upgrading previously, but it's nice to be extra safe.
The Golden core will also help in case of incompatibility issues or other core-update issues: a user can simply put a jumper on two header pins on the AppleSqueezer GS Turbo to boot from the original known-good factory core again, and then perform an update to a different core. This should make core updating worry-free. The jumper also forces factory settings, so that e.g. if you disabled memory extensions, but you don't have enough physical memory in your IIGS (leaving you without being able to boot into GS/OS), you can just use the jumper to get back in.
The AppleSqueezer GS Turbo uses less power, thanks to the absence of the physical 65C816 + level shifters, so it runs a little bit cooler
Enough of the purple: it's yellow! 😀
The new AppleSqueezer also fits physically better into a ROM01 machine, as the PCB is smaller and doesn't reach the capacitor that the AppleSqueezer GS v2 would reach (which, for some people, made it a bit tricky to install on a ROM01).
The CDA and CDev control panels were rewritten, so they support the new AppleSqueezer GS Turbo, while also keeping support for the other AppleSqueezers, and they offer more byte-level verification while updating the core. The speed settings for the new AppleSqueezer GS Turbo are: 2.8, 7, 14, 21 MHz and 48 MHz. The setting takes effect immediately, without reboot. Switching acceleration off (after a Control-Apple-Reset) still gives stock, cycle-exact timing.
What doesn't change
Of course, the AppleSqueezer GS Turbo still includes these features that are already used by many users:
HDMI support. With the same improvements recently introduced into core 15 (see the previous blog post), such as 3200 color mode, mixed mode, centered display, border colors, and more.
SD card support. Even more useful today with the help of the SD Builder tool (available from https://www.applesqueezer.com/downloads) which allows you to add up to 4 .po hard disk image files to the SD card, and it automatically adds the AppleSqueezer control panels to the startup volume. Some great disks are available here for you to try: https://whatisthe2gs.com/bootdisks/ The SD Builder tool also installs the latest AppleSqueezer control panels on the first volume automatically, so it's a great way to get started.
14MB of RAM expansion (13MB available to GS/OS), 224 MB RAM available to programs designed for this.
For those who will ask: like the AppleSqueezers that preceded it, the AppleSqueezer GS Turbo doesn't support DMA (if you have a slot card with a DMA option, such as some SCSI cards, switch it off). DMA wouldn't really benefit from these speeds anyway, as it's limited to the (relatively very slow) speed of the IIGS bus, about 1 MB/s, at any CPU speed. DMA, while nice, would also require access to a slot, which makes the whole setup more unwieldy and slower to produce. And for the main reason people want DMA, fast disk access, the built-in SD card is already faster than DMA could be.
Some benchmarks!
Here are some benchmarks, as tested by BENCHMARKv5.2mg, compared to stock and other accelerators:
These hard benchmarks may be impressive, but of course a typical user isn't running benchmarks all day, so it may be somewhat meaningless. But as some of you know, Doom was recently ported to the IIGS. And this gives perhaps a more imaginative comparison!
The AppleSqueezer GS v2, with the latest core 15, runs it at a pretty decent 6.8 frames per second (FPS). However, if you use the AppleSqueezer GS Turbo, you can run this game at 23 FPS!! This makes it very playable, and in fact, it would allow the creator of this Doom port to improve the graphics for this game on the IIGS!
Booting into GS/OS takes about 11.5 seconds from the built-in SD card (tested with 6.0.4 boot disk from here: https://whatisthe2gs.com/bootdisks/, when the Slots -> StartUp control panel is set to "ROM Disk")
Out Of This World is another game that runs really well, including in full screen mode!
More speed allows for more fun!
Given these improvements, I think the new AppleSqueezer GS Turbo unlocks quite a few exciting new possibilities for Apple IIGS development. With this level of performance, even though the IIGS doesn't come with a blitter or other sprite hardware, like for example the Amiga did, I think software rivaling (and exceeding!) some of the best Amiga games should now be possible on the IIGS. Better yet, impressive 3D games are now a real possibility as the Doom port shows. Perhaps even a game like Quake could be ported now?
I've seen quite a lot of new IIGS game development lately, and hopefully this will allow developers even more freedom, creativity, and push the envelope of what's possible on a IIGS. While AI isn't great in many ways, I do see that a lot of new retro game development is assisted by it, so I'm hopeful that quite a few new games could be ported to the IIGS as a result, in addition to entirely new games being created from scratch!
Famous Amiga games like Flashback (the successor to Out Of This World), The Secret of Monkey Island, perhaps even Turrican II, and many others come to mind. I think some of these could run really well on the AppleSqueezer GS Turbo, while also taking full advantage of the IIGS's excellent sound capabilities. Of course, some games would be more challenging to port than others, particularly those relying heavily on the Amiga's custom graphics hardware. But wouldn't it be great to see them running on a IIGS? (Then again, I may be somewhat biased, having grown up with an Amiga ;)
RAM prices :(
Unfortunately, due to the AI boom, which seems to eat up pretty much all RAM chips the planet can produce, RAM has become very expensive today. The price I pay for these chips has risen about 10x. This means that unfortunately I had to raise the price of the latest AppleSqueezer GS Turbo slightly, to 325 EUR. I hope people will be understanding of this, but at least you're now getting a lot more speed and other functionality for your money.
Availability
The new AppleSqueezer GS Turbo is available from today, but I'm expecting them to run out rather quickly. And given the crazy RAM price increases and other limitations in the chip market, I'm not yet sure when I can create new stock. Of course I'll do my best - but you may have to be patient! Also, because I'm expecting quite a bit of demand, the shipment may take a little bit longer than usual, up to about 10 days.
Upgrade options
The new AppleSqueezer GS Turbo uses a more powerful Xilinx FPGA than the previous one, which unfortunately means that AppleSqueezer GS v1 or v2 users cannot be upgraded to the new Turbo speeds.
However, I don't want anyone who recently purchased an AppleSqueezer GS v2 to feel they've missed out! If you bought a new AppleSqueezer GS v2 from the applesqueezer.com website within the past 3 months, please contact me for a discount coupon toward a new AppleSqueezer GS Turbo (before ordering)!
The existing AppleSqueezer GS v2 will still be available for those who prefer to use a real, physical 65C816 - at least for the time being - and I lowered its price to 250 EUR (while supplies last).
Any chance the V2 will get sound on HDMI, or is it just not there on a hardware level?