Drum Machine OSes

[LoneStar81]

Here are some OS ROM dumps of various machines:

http://lonestar.madtracker.net/OSpack.rar

Contents:
Alesis HR-16, HR-16:B
Kawai R-100
Korg DDD-1, DDD-5
Roland R-8
Yamaha RX5

Filenames contrain EPROM type (i.e. 27C256) and sometimes part name/number.
Viewing them you will notice that all on-display text is stored unencrypted and unscrambled. which makes personalising the OSes easy.

[Gordonjcp]

Viewing them you will notice that all on-display text is stored unencrypted and unscrambled. which makes personalising the OSes easy.

Not in the HR16 family, they're not!  The ROM is scrambled due to a hardware peculiarity which I've detailed in the past.  To descramble it, you need to grab and build svn://www.nekosynth.co.uk/nekosynth/utils/hr16utils/ to flip the lower eight bits of the address.

[Circuitbenders]

So i've taken a dump of the OS from a Kawai R-50 and edited the file so that in theory it should give a customised startup with different text on the screen. All i've done is find the text '*.KAWAI.R-50.*' and used a hex editor to change it to 'CIRCUITBENDERS' which convieniently has the same number of characters, and then resaved the .bin file. The problem i'm having is that i can't seem to write the new file to another chip as i get an error every time. The original file will write fine but the new one won't.

What am i doing wrong here?

[Gordonjcp]

Silly question, but have you blanked the chip?

Where do you get an error, in the EPROM programmer or on the drum machine?

[Circuitbenders]

I've tried it with a few 27C256 chips all of which were erased beforehand and all of which can be programmed with the original unedited OS file.

The error happens with the EPROM programmer. When you click program it more or less immediately comes up with 'Error at 0xD8' or something similar. If you read the chip back theres some stuff programmed but it looks to be garbage.

Should this actually work in theory? If you just alter the Hex values so the the Ascii output has different text should you be able to just resave it as a .bin file, burn it to a new EPROM and the drum machine will display the new text? I'm wondering if i've missed out some essential step like recompiling it or something. 

[Gordonjcp]

That should be okay.  Either your EPROM programmer isn't configured properly or the EPROM is knackered, or incompletely erased.  It should read 0xff throughout when it's properly blank.

[Circuitbenders]

In a classic case of not seeing the wood for the trees i've worked out what the problem was. For some reason my programmer software just didn't like the fact that the filename of the edited bin file had brackets in it.

I just changed 'KAWAI_R50_OS_27C256-(CBstart)' to 'KAWAI_R50_OS_27C256-CBstart' and now it works fine.

[Gordonjcp]

Sweet!

[sneakyalien]

Hi,I read with interest your experiments with  drum machines and was wondering if in your opinion it is possible to remove the roms from the extra sound cartridges of an rx5 and read the data from them  using an Eprom blower,read the data into sound forge and then replace the data with new sounds and blow the new data to a new Eprom.This Eprom would then be placed back onto the circuit board of the cart and re-inserted into the RX5 giving it new sounds.
Is this possible or am I loosing the plot???
I have opened the cart up and it uses two mitsabishi chips
chip 1 is a M5M23C100-512P 645100
chip 2 is a M5M23C100-513P 643102
I understand the RX5 uses Yamaha AWM encoding,would this be a speacial weird unfathomable format or would it be raw binary.
Sorry for all the dumb ass questions,as you can tell I'm not very techy.
best regards.

[Gordonjcp]

Those will be JEDEC-format 1Mbit mask-programmed ROMs that could be replaced with EPROMs or flash memory.  Try 27C1000 for reading.

[gretagrain]

Is it possible to reburn the OS on a Roland R-8?
I have one that powers up but it looks like the os is fried...garbled display and no sound.

Any info is greatly appreciated.

Pete

[LoneStar81]

Is it possible to reburn the OS on a Roland R-8?
I have one that powers up but it looks like the os is fried...garbled display and no sound.

Any info is greatly appreciated.

Pete

Sure, you just burn the OS dump on a new 27C010 aka 27C1001 (8bit x 128k, 1Mbit) eprom and you're set.

[dJ dAb]

Here are some OS ROM dumps of various machines:

http://lonestar.madtracker.net/OSpack.rar

Contents:
Alesis HR-16, HR-16:B
Kawai R-100
Korg DDD-1, DDD-5
Roland R-8
Yamaha RX5

Filenames contrain EPROM type (i.e. 27C256) and sometimes part name/number.

Viewing them you will notice that all on-display text is stored unencrypted and unscrambled. which makes personalising the OSes easy.

I'll add my images shortly...
Drumulator
LinnDrum
Drumtraks
Oberheim DX

[Glitch Militia]

Anyone interested in Roland R-8 Mk.II ?

[lazydog]

the HR16 has a nice OS: i can't remember the button presses,
but you eventually get the name of the OS designer come up.
what a shame they didn't have that nice orange LCD on the
SR16 - which is essentially the same idea, updated.