Update on the Motorola DSP 56300 emulator, for the Access Virus C plugin (called Osirus):
The generous developers community’s website provides the software instrument also as a Linux Arm64 (aarch64) package, either in VST2, VST3 or CLAP format.
To my limited understanding, using Osirus in Zynthian should just require a VST Linux wrapper, and as soon as ZynthianOS switches to aarch64 it might be possible to exploit the RPi5 improved CPU performance, to sustain the required DSP 56300 duty-cycle (136 MIPs for the Virus C implementation - for a comparison, the test console provided by the developers returned 460 MIPs on my i7 quad-core iMac).
As for the Access proprietary synthesis program, I quickly traced a third-party open repository with both the Virus B and C ROM (reverse-engineered?) software, that the 56300 emulator site cannot provide for obvious copyright infringement reasons:
Today I have had a try at Osirus on Cubase/Mac, and - my goodness - it simply sounded phenomenal, going straight away in the top region of my preferred software instruments, be them freeware/open source or commercial.
I think that embedding Osirus in a future stable release of ZynthianOS would greatly improve the synthesisers armoury of this project, complementing the features of the local Swiss army knife Zynaddsubfx quite perfectly.
It’s a nice thought, but I’m not holding my breath; at the end of this thread Access Virus emulator on Zynthian? - #5 by JayBee it was concluded that the RPi4 is probably too slow even if the emulator can be improved and the Pi overclocked.
Indeed, as a (very) loose MIPS comparison, a while ago, I tried running the test application that the Osiris team brought out on a ten year old laptop (i5-2450M), which is about as powerful in terms of CPU power as the RPi4, and as I recall it didn’t even managed to run the Virus B successfully.
I certainly wouldn’t recommend holding your breath - we’re talking about many months, perhaps even years to complete the transition, but between the improvement due to switching to 64 bit, multiplied by the improvement between RPi4 and RPi5, I think we have a good shot at getting enough CPU power to run either all or some of the Access Virus versions via the DSP 56300 emulator. And if not, well, there’s always RPi6 or maybe RISC-V! GodSpeed Zynthian!
I found this thread online specifically looking to see if this had been developed. The idea of a software emulation being ported to open source hardware, so that the Virus B, C, and eventually the TI might live on past it’s now discontinued and unsupported hardware.
I just executed the test scripts on my raspberrypi5.
For Virus B 108 MIPS are needed,
for Virus C 136MIPS are needed.
I got an average of around 315 MIPS with the Impact script and 236 MIPS with the Indi on the raspi5,
with around 72,5% cpu idle.
This was done on raspian/debian x86_64 with default cpu settings and the C firmware.
I was exactly set in about the same experimental direction in these days. I was indeed attempting to devise the right installation environment for the DSP 56300 emulator on a Raspi 5 with 64 bit Bookworm OS desktop, predicting - as it turned out to be - a performance of approximately 300 Mips at the factory CPU clock.
That is vary enticing, and I think that it might propel @jofemodo and @riban to embed Osirus aarch 64 with Virus C Rom, in the coming Oram stable release.
That is true, and I’m not personally very conversant in the intricacies of technology copyright. Still, since Access are still liberally making the B and C ROMs publicly available on the web, I suggest that Zynthian could just include the Osirus DSP emulator plugin, and (I guess) nothing would prevent the user from SSH-ing the cross-platform ROM file into the plugin directory.
Yes that’s true, however, a month ago the news was all over the web that production of the Virus TI (TI2 I believe although it was never labelled as such by Access) has ceased “several months ago”.
Which I’m thinking will bring an emulated TI into reality in the not-too-distant future.
This Is honestly sad news, for the synthesiser aficionados community. I have been wondering often, not having ever owned a Virus (but sometimes played it in shops), why Acces had stopped developing the TI2 for so many years.
I reckon that this instrument makes for one of the very few cases where tha synthesis code is so exceptionally well designed and written that the final quality of the musical machine is prevailingly due to the ingenuity of the algorithms (the proficiency of the Virus C ROM on the DSP emulator is a strong testimony to this premise).
On a lighter mood, if Access actually discontinues their synthesizers line, a whole new area for plugin developers opens up, and also for employing more overtly the 56300 emulator software (in Zynthian!)
According to Blog | DSP56300 Emulation Blog | Emulating the Access Virus C & other virtual analogue synthesizers there is also the possibility to change the used samplerates (44.1 and 48 kHz in hardware) more flexible (+ 32, 64, 88.2 and 96 kHz) resulting possibly in more or less available voices. Furthermore you can over-/underclock the DSP resulting in less or more frequent voice stealing, but on the other hand maybe enables the usage on weaker CPUs at the expense of less available voices.
BTW: OsTIrus is in development and will be released to the public when it’s ready, now that sales and further synth dev have been stopped. (According to Discord)
Thanks @Tithrion , you definitely are the bearer of prerty sweet updates, on the DSP 56300 emulator development, which looks in shining shape after the latest news about the demise of Access synthesisers.
Has someone had any luck, in running an aarch64 Osirus plugin (DSP 56300 emulator) on Raspi 5, with Raspberry OS/Bookworm 64?
I am trying to install both DEB and RPM packages (VST2, VST3 and CLAP versions) in Reaper, but the DAW requires the Virus (BIN) ROM files to reside in appropriate directories, under $/opt/usr, which I am struggling to locate despite having correctly executed the packages.
Furthermore, I wonder if LMMS could maybe be a better choice than Reaper, in terms of successful installation and/or CPU performance.
Is there someone here with a positive experience, in running the plugin on an Rpi5?
