The Emax is now legally an adult. It has been 18 years since it's launch. Unfortunately, with electronic equipment this means it's time for things to start failing. You can't go to E-mu for support, they no longer offer it. Luckily, quite a few members of this group are very knowedgeable and over the years I have collected a lot of information and resources to help with repairs.
Upgrades: The Emax is not really expandable. You can use a different OS based on the model you have that may add some new functions, but the memory amount is fixed at 512k and most pre-HD models can not be modified to add a hard drive.
Disclaimer: You should never perform any repair on an Emax or Emax II if you are not well-experienced in electronic repairs.
Diagnosis Mode: The Emax and Emax II have a hidden menu where many of the hardware diagnosis procedures are kept. Select the MASTER module. Choose option 9. The display will give you a choice of 1-8. Again, press 9. When prompted for a password, enter 3629 ("EMAX" on a telephone touchpad). These functions include disk and memory testing functions.
Disclaimer: Be warned that most of the hard drive utillities will erase anything stored on your hard drive. Use at your own risk.
Hard Drive: There is no way to upgrade a non-HD Emax to HD status at this point. Route 66 Studios report they are working on a SCSI chip. If you have an HD model it more than likely came with a Miniscribe 8425s (or 8425sa) 20Mb SCSI 1 type hard drive which is long out of production. The recommended repair for a faulty internal hard drive is provided by the Emulator Archive. They have step by step instructions on modifying an HD model to a Plus! model and adding an external Iomega Zip Drive for storage. it is unsure if you must first perform the SE Upgrade noted below.
Floppy Drive: the DS/DD floppy drive of the Emax and Emax II is not a standard PC floppy drive. Orginal drives were made by NEC, but later models have a Mitsubishi Full Height 3.5" MF353B - 12 UJ or MF353BA - 12U. The main difference here is that they can have their ID# set to 0 where standard drives nowadays are hardset to ID1. Your best source for replacement floppy drives is Route 66 Studios. They also offer blank DS/DD diskettes $11 for 50. A floppy drive out of a Mac Classic will usually work as well.
Power Supply Unit (PSU): Having the power supply give out or go faulty seems to be happening more frequently. There are no Emax PSUs left through E-mu. A member of the group was able find a suitable replacement from a mail order catalog. Contact the list for more information.
SE: Upgrading an Emax or Emax HD to SE is not as simple as getting a copy of the correct SE OS. Before the Emax can use a SE OS it must first have the SE Upgrade disk ran on it. For a long time this was thought to no longer be possible. The SE Upgrade disk is a self-corrupting installation disk that updates a special EEPROM inside the Emax. After running it the Upgrade portion is corrupted, but the banks are left intact. Unfortunately E-mu accidentally destroyed the Mac that the information was stored in so not even they could create more disks.
Fortunately, in February 2004 a list member named Carsten Ender notified us that he had managed to make an image of an unused SE Upgrade Disk with the EmaxUtil program available in the lists Files section, he uploaded the image there as well. It has been succesfully used by a fellow list member, midi_patchbay, who posted his instructions and gave me the permission reprint them here. I have modified his post to be more generic.
REMEMBER, the Emaxutil requires DOS 6.22 or earlier to work. Do not use the Emaxutil in Windows or in a Windows DOS Box. Though it may appear to work the image will more than likely be corrupt.
First, thing you need to do is boot into MS-DOS 6.22 or earlier, if you don't have DOS 6.22 you will need to find a copy of a DOS 6.22 floppy boot diskette. Since DOS 6.22 can not read either the NTFS or FAT32 file system it may be necessary that you will create a partition that uses the FAT system. If you happen to have two floppy drives in your computer, you can just use those. In midi_patchbay's instructions he copied the files "emaxutil.exe" (26k unzipped) and "seup.em1" (800k) to a FAT formatted hard drive.
IMPORTANT NOTE: You must first format a 720k Double Density diskette in your Emax before writing the image file to it. He tried writing to a DOS formatted 720k Double Density diskette and the Emax would only respond with "Disk Error". After formating a floppy in the Emax before using Emaxutil it worked great.
Change to the FAT format hard drive and replace the MS-DOS 6.22 diskette with the blank Emax-formatted diskette. Run emaxutil.exe and have it write the image to the floppy diskette. This takes a couple of minutes but not too long.
When Emaxutil finishes insert the diskette into the Emax. Turn on the Emax and it should begin loading. After loading it displays a message saying something like "SE Update Complete, Please Reboot"
Turn the Emax off, then back on after a few seconds. If you have a non-HD model it will boot from the same diskette again this time loading the sound bank. The software version should report as "Emax SE rev 1.1". If you have an HD model you will want to boot with the SE HD OS diskette and the software version will report as "Emax SE HD rev 1.1".
You will then need to use the Copy OS function to put the proper OS on all your existing floppies and/or the HD.
NOTE: I have never performed this upgrade myself. These instructions are modified from a post to the list.
Plus!: The Plus! OS requires
that your Emax already upgraded to SE. It's main new feature is the
ability to select the SCSI ID where it should load banks from. This
makes modifying your Emax to have an external SCSI port and using
a removable media drive like a Iomega Zip possible.