[HN Gopher] Fixing a 30 year-old Roland synthesizer Bug
___________________________________________________________________
Fixing a 30 year-old Roland synthesizer Bug
Author : montag
Score : 60 points
Date : 2022-09-12 21:11 UTC (1 hours ago)
(HTM) web link (www.vogons.org)
(TXT) w3m dump (www.vogons.org)
| ajxs wrote:
| Awesome work! I love the care and attention that people put into
| understanding these devices.
|
| I'm currently in the middle of a vintage synthesiser hacking
| project as well. Last year I made a fully annotated disassembly
| of the Yamaha DX7 firmware, and did some other technical analysis
| of the synth. Since then, I've been waiting for a chance to put
| this knowledge to good use. I found a DX9 on a local trading
| site, and I'm in the process of hacking its firmware to remove
| the 4-operator restriction that made it such an unpopular synth.
| NexRebular wrote:
| I wonder if DX100 firmware could be hacked like that as well,
| it being another of the 4-op beasts too
| tomcam wrote:
| > Last year I made a fully annotated disassembly of the Yamaha
| DX7 firmware
|
| You beast!
| pinewurst wrote:
| The Kawai K5 I used to have was also 8096 based.
| Gordonjcp wrote:
| Intel 8097 in the Roland W30, and I think also the S50.
| digitailor wrote:
| The S550 is the unit I was fixing mentioned in another
| comment, that one was a 8095
| digitailor wrote:
| Didn't know that: hard to believe they managed to pull off
| additive synthesis on an 8096. That's impressive
|
| I had a later Kawai K5000 which added short PCM samples for
| attack transients. That thing was crazy, foolishly gave it away
| more than a decade ago
| pinewurst wrote:
| I received a final software update from Kawai and had to open
| it to install the EPROMs, which is how I saw it. It was a
| very cool synth - very high quality feeling.
| digitailor wrote:
| This is cool, so TL;DR: The 3rd gen run of a Roland early digital
| synth product had an unresolved timing issue causing pitch
| playback problems. Recently, investigation revealed they hadn't
| accounted for an Intel MCU part sub. The spec indicated the sub
| part was running too fast. They downclocked it via crystal swap
| which destroyed the unit's MIDI timing. So they located the
| control ROM instructions to modify to fix the resulting MIDI sync
| issue and burned a new one: 0x1A8D: 1D5Fh ->
| 1388h 0x215C: 17h -> 0Fh 0x216D: 1D5Fh -> 1388h
|
| That's it. Surgical.
|
| I spent some time inside an early Roland sampler of this era
| during the pandemic. It's really well engineered stuff that
| sounds great.
| tomcam wrote:
| Ah, relief. Big Roland fan but don't have this particular piece
| of gear hello trouble following TFA
| Gordonjcp wrote:
| I guess it makes sense that it would be a common divider ratio
| (5000) but $1388 leapt out at me from disassembling the Ensoniq
| Mirage firmware.
| digitailor wrote:
| That's a cool project. Mirage patches got edited in hex on a
| two digit panel screen, right?
|
| Spent time with an Ensoniq ASR-10 rack that I managed to fry
| with AES/EBU noise on the analog ins. Overhauling the PS did
| not solve :/
| keepquestioning wrote:
| This reminds me of the binary patching done in The Martian
| film.
___________________________________________________________________
(page generated 2022-09-12 23:00 UTC)