Q: Can I upgrade the memory in my Emax 1 unit from the factory 512KB?

A: No. The memory cannot be increased. This is a limitation of the device.


Q: Can I upgrade the memory in my Emax 2 unit from the factory 1MB or 2MB to a larger amount (maximum 8MB) ?

A: This depends on whether or not you have the memory expansion board and the proper PALs.

Assuming you do have the expansion board and it is populated with memory chips and the proper PALs installed, the memory may be enabled via the Scrambled Megs procedure.

EPR Electronics (Florida, USA) provides this service

Some of the PAL / GAL memory IC files are now available on the Yahoo! Emax Users Group files section. Please review the Expansion guide and the available PAL/GAL files to see if you may be able to increase the available memory in your unit. The files are made freely available so you can program ICs yourself at minimal cost. Complete details regards the specific required PAL / GAL IC sets for each possible memory configuration are detailed in the guide.

Emax II Memory Expansion

DISCLAIMER: Use of the PAL/GAL files are at your own risk, and have no inherent, explicit or implicit guarantee, warranty, or suitability for a specific purpose. They are provided solely on an “AS/IS” basis.


Q: Can I upgrade my Emax 2 unit from MONO to STEREO?

A: If you can find a kit (which are now very rare), it is possible. However, no one has been able to duplicate the STEREO PAL, and therefore it is usually easier to track down a unit which has already been updated to stereo.

Further details regards the Stereo Upgrade are available in the  Guide.

Emax II Stereo Upgrade


Q: Can I upgrade / replace the EL foil Backlit display in my Emax 1 or 2?

A: Yes, although part numbers and options vary. There are many replacement options available: stock replacement, Backlit LCD, VFD, OLED.

Because of the available variety / options in display and changes to part numbers, etc which can occur, we will not link to any particular part here.

Of note, many displays do not have the same pinout as the Emax, so a new display usually has to be hardwired, requiring some soldering skills / experience for proper installation.

Local electronics shops or Synthesizer repair shops can usually perform this work for you.


Q: Can I add SE capability to my Emax 1 unit?

A: Yes, the SE Update file is availabe in the Emax Yahoo User’s Group files section (free, login required).


Q: Can I add SCSI capability to my Emax 1 unit?

A: Probably, please see the following pages for further confirmation:

Board Identification- version 2: https://djtbs1.files.wordpress.com/2010/10/emax-rev2b2.jpg?w=150&h=112

Board Identification- version 3: https://djtbs1.files.wordpress.com/2010/10/emax-rev3b2.jpg?w=112&h=150


Q: Can I replace the floppy drive with a new one, as the currently installed drive is not functioning properly?

A: Yes, there are a couple of options, although there are some caveats.

– standard PC 3.5″ drives will not work “out of the box” as they use the drive selection standard of A/B, while Emax uses a modified Schugart specification where the drive is set with DS0 (drive select 0) jumper.

— most standard PC 3.5″ drives currently available at computer stores do not have a Drive Select (DS) jumper.

– stock replacement drives may be available – Mitsubishi and TEAC are the most likely vendors to manufacture a capable replacement.

– it is also possible to install a slim floppy by using an modified adapter.

Detail here:



Q: Can I replace the floppy drive with one of the USB Floppy Emulators I have seen on the internet?

A: There is one known working option for this: the HxC Floppy Emulator which has support for Emax.

Note that “Gotek” and other non-branded Chinese floppy Emulators support DOS only. Emax uses a proprietary format, not DOS disks, therefore these other floppy emulators will not work.

** UPDATE: There has been some talk about the HxC firmware being used on cheaper drives (Gotek, etc).  Some information has been posted online that the cheaper drives do work, but can have read write issues. Note that the HxC has a metal frame, while the “copies” are plastic units, so that’s how they can be told apart. YMMV


Q: Can I just remove the floppy drive and use Emax without it?

A: The Emax does a boot search for the floppy and expects the floppy to be present.
While it is possible to jumper the Floppy connector on the logic to ignore the floppy drive, it would then be impossible to perform diagnostics on the machine if it is failing to boot as the diagnostics is a special floppy disk.


Q: Can I install an HxC Floppy Emulator along with the stock floppy drive?

A: The Emax firmware does not allow for multiple floppy drives.  This is the reason why SCSI was added to Emax. SCSI allows access to more banks by making multiple drives available to the unit (up to 6 drives with 35 banks each). One Emax user added a switch on the power lines for the floppy and installed an HxC in parallel with a slim floppy. I cannot explicitly recommend this as a solution for the average user.


Q: What kind of floppy disks can I use with Emax?

A: Emax 1 and Emax 2 both use 3.5″ DSDD (double-sided double-density) disks. While it is possible to cover the HD  (high density) hole on 3.5″ DSHD disks, the magnetic field of these disks is different. It is very likely the sound banks may corrupt over time due to magnetic field differences. It is recommended to purchase new DSDD disks. They are available from many vendors on the internet.

Use of 3.5″ HD disks can result in “Data CRC Error” and “Disk Error!” messages. The messages can occur during format, write, or read of the incorrect disks.

Note that a bad floppy drive (mis-alignment or failing read / write head) can also result in these messages as well.


Q: I need to repair my Emax 1 or 2 – is the service manual available?

A: The service manual is still copyrighted by E-mu Systems. It can be purchased from musicparts.com


Q: I want to replace my Emax Hard drive with a flash media drive. Will any drive work?

A: No, there is a list of qualified devices in the Yahoo Users Group database section.

The short list of known working devices are: MicroTech PCD-15, MicroTech DPAI-SCSI (also called PCD-25B), SCM PCD-50b, SCM PCD-60b.

Note 1: The PCD-47b model does not work and should not be purchased

Note 2: PCD-50b and PCD-60b may only use the PCMCIA slot. The other slots will not work with Emax.

Note 3: Some IDE drives will work, but only where using an ACARD SCSI to IDE bridge (7220U / 7220UW). Other brand IDE bridges have been tested, but did not work.


**** IMPORTANT: CF to IDE adapters that are available on the web / ebay which simply are made from a connector for CF and the IDE connector and no Logic chips on the board DO NOT WORK.

These adapters do not take into account buffering, bus timing, etc.

Attempts to use these cheap adapters will result in messages on the Emax such as “Hard Disk Error”, “Catalog Error”, and others. ****


Q: Can I boot my Emax from an external drive (Flash media, Zip, or Hard drive)?

A: Yes, assuming the drive (regardless of type) can be set to SCSI ID # 0, you should be able to boot from an external drive.

Note: The above answer assumes you do not have an internal HD also set to SCSI ID # 0.  Basic SCSI rules / guidelines apply. Additionally, the above answer assumes you are discussing a known Emax compatible drive.


Q: Can I use an IDE hard disk in my Emax?

A: Not without an ACARD 7720U/UW SCSI bridge. Emax does not have an IDE interface, only SCSI.


Q: Can I use an Zip Drive with Emax?

A: Yes. There are several possiblities

1) An “Internal” SCSI Zip can be used (either in Emax case or in external enclosure), and where SCSI ID is set to ID 0- Emax CAN boot from it

2) An  “External” SCSI Zip (or the external blue ones with dual interface (support for parallel and SCSI))- these are set to ID 5 or 6 and can be used, but Emax CANNOT boot from it.

3) An “Internal” ATAPI Zip can be used (either in Emax case or in external enclosure) where the ACARD 7220U/UW or ACARD 7226Q bridge is used to connect to the SCSI.

SCSI ID 0 can be set on the SCSI bridge and Emax CAN boot from it.


Q: What is the maximum size Hard Drive or media which can be used with Emax?

A: Emax 1 can only use a formatted maximum size of 20MB (although 256MB flash media or 250MB Zip can certainly be used, you will never be able to USE more than 20MB of the media size). Emax 1 supports 35 banks per SCSI ID (these limitations are in the OS / firmware which cannot be modified).

Emax II can use up to 1GB of size. Calculation of proper size depends on Emax II installed memory. Emax II can access 99 banks per SCSI ID. So if you have an Emax II 8MB unit 99 x 8MB = 792 MB. If the Emax II is 4MB, then 99 x 4MB= 396MB, and so forth.


Q: What is the latest OS version for Emax II?

A: OS version 2.14 is the latest and works in all Emax II’s that I am aware of.


Q: What is the latest OS version for Emax 1?

A: This is more complicated than for Emax II, because unlike Emax II, there are many variations which require different OS versions.

The latest base version is OS 3.2 (which does not support SE features and also does not support SCSI features) – any Emax can boot with this OS.

non-HD Emax (no SCSI) but Emax DOES have the SE update should use  SE 1.1 OS version

non-SE Emax (no SE) but Emax which does have SCSI should use HD 1.1 OS version (this version does not support SCSI ID other than 0 – so no external drives with this OS).

Emax which have SE AND SCSI (HD) should use PLUS 1.0 OS version (the latest available which supports all features including external SCSI drives and multiple SCSI ID’s)


NOTE: Attempts to boot an Emax 1 from an OS that supports features which are not installed in that particular Emax results in failure of the Emax to boot.


Q: After I booted the Emax, I get a wrong software message when I switch floppy disks or switch to another HxC image?

A: Emax does not have enough memory space to load the complete OS into memory.
Every time the user chooses a section (example: Preset Definition) which is not already in memory – Emax at that time reads the instruction for the section which is requested from the disk.

Because the way Emax OS is written on the disk- each section is at a specific location on the disk.

The pointers to section locations on the disk are loaded on boot.
Different OS versions do not have the sections in the same exact locations – as features changed or bugs were fixed, the code size would change, the sections would have to move on the disk to different sectors, and as a result the section pointers would also change.

When a disk is physically swapped out (or new image selected, for HxC) and a different OS version resides in the newly inserted disk / selected image, the section locations and the pointers loaded into memory at boot are no longer in sync. Emax has no way to resync the pointers.

Therefore, when Emax accesses the disk for “Preset Definition” and instead on this different OS, it finds “Preset Management” or lands in the middle of a code section instead of at the beginning of the expected section, Emax then displays an error message.

It’s important that the Emax OS in use is consistent across all floppy disks / HxC images to avoid this issue.

The Emax manuals do mention that where a new OS is available and in use, the new OS must be applied to all disks.



This FAQ is for informational purposes only. The author assumes no liability for any use or mis-use of the information contained herein.

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