Home
Search
Links
Manuals
Rare Analog
Synth DIY

Site Intro
 

Overview
Ads & Reviews
Diskette Drive
Drum File
Photos
Repairs
Samples
SP-12 Librarian
Technical
Upgrades
 

Created by
 Western Graphics
Last modified
 13 March, 2004
 

SP-12^®: Upgrades & Add Ons

Factory Upgrades The E-mu Systems factory have long since stopped providing upgrades or spares for the SP-12. Users are on their own, and there are no third party suppliers either.

Sample Memory The standard SP-12 can be upgraded to TURBO with a full 5 seconds of sample memory - the longest single sample is 2.5 seconds, by adding 18 additional memory chips into the vacant sockets on the motherboard, and by replacing the existing memory addressing PAL chip with a new one. The upgrade is for both sample and sequencer memory.

The Emulator Archive hopes to have a TURBO memory upgrade kit in the future, email us for details.

SP-12 TURBO Upgrade  (244 KB/3 pages)

OS Upgrades The SP-12 operating software resides in two EPROM's at IC location 114 and 115 on the motherboard, underneath the mains transformer.

OS versions 1.6, 1.8,  2.1, 2.4 (31 January 1986) and 2.6 exist. The latest OS we are aware of is Version 2.6, current in Spring 1988. An OS version (8.7) for Phil Collins SP-12 has been reported. If you wish to upgrade to OS 2.6 please contact us.

OS 2.4 implemented SPECIAL #20 which provides TUNE/DECAY RANGE SELECT.

Sample and Song Librarian Software Two companies produced Mac software for the SP-12. Blank Software produced Drum File 1.2 which provided sample and song transfer to a Mac, and librarian and sample import facilities. It cost $295 and was available between 1986 and 1989. Then Blank Software was taken over by Passport and the software appears to have been killed off. It is not available new. more »

A second company called Water's Edge produced a similar Mac application but without the sample import facility. The software is still available for $99, and there are more details on the software here. more »

MIDI Sample Dump The SP-12 (OS 2.4+) does support MIDI sample dump and a user who has the SP-12 used by Phil Collins, reports a new OS version and MIDI sample dump lsited on the front panel.

Floppy Drive E-mu Systems introduced removable storage for the SP-12 by using an external Commodore computer diskette drive. This is a 5.25" self contained unit with its own power supply and a serial interface. It was the best choice in 1985, when 3.5" drives had yet to appear, and an internal 5.25" would have taken up too much room. The diskettes are used to stored samples and sequences

1541 Operation Notes First, make sure that you've removed all diskettes from the disk drives before powering on. Power the 1541 on before the SP-12 The 1541 disk drive will have its green light on, and then the red drive/error light will blink. Once the red drive/error light has stopped flashing on the drive, it is safe to begin working with it.

To open the door on the drive, simply press the door catch lightly, and the door will pop open. If there is a diskette in the drive, it is ejected by a small spring.  Take the diskette to be inserted, and place it in the drive face-up with the large opening going in first and write-protect notch to the left . Press it in gently, and when the diskette is in all the way, you will feel a click and the diskette will not spring out.  Close the drive door by pulling downward until the latch clicks into place.  Now you are ready to begin working with the diskette.

Remember to always remove the diskette before the drive is turned off or on. Never remove the diskette when the red drive light in on! Data can be destroyed by the drive at this time!

1541 Technical Description The 1541 has circuitry for both a disk controller and a complete disk operating system, a total of 16K of ROM and 2K of RAM memory. This circuitry makes the 1541 disk drive an "intelligent" device. This means it does its own processing using a "pipeline" software system. 

The 1541 disk drive contains a dual "serial bus" interface.  This bus was specially created by Commodore.  The two ports at the rear of the drive allows more than one device to share the serial bus at the same time.  This is accomplished by "daisy-chaining" the devices together, each plugged into the next. Up to five disk drives can share the bus simultaneously, but the SP-12 can only read one.

The original drive used was the Commodore 1541, which was more usually used with the C64 computer. It stores 170 Kbytes on a DS/SD diskette, but works at cassette tape speed, and is therefore rather slow!

5.25" DS/DD diskettes can be used today, although the storage space remains the same. If you have a SP-12 TURBO, samples may take two diskettes to save, as there is more sample and sequence storage to save.
 

Proven Drives Commodore 1541
   (1984)

 Commodore 1541-C
   (1986)

Recommended
 Commodore 1541-II
   (1988)

Unsupported
 Commodore 1581
   3.5" diskettes
 

You will be able to find a second hand one on eBay, alternatively you could buy a new/recon one at Creative Micro Designs web site.
              more »

The only problem with the 1541 is the very slow data transfer rate of 400 bytes/sec. This means samples load very very slowly. You are much better off using Mac software to hold your samples. more »
 

The advantage of the 1541-II is improved reliability thanks to an external power supply and better PCB design, however you need to set its device ID to 8 via DIP switches to work with the SP-12.

Left Right Device# UP UP 8 DOWN UP 9 UP DOWN 10 DOWN DOWN 11

The SP-12 connects to the Commordore floppy drive by means of a standard serial cable with 6 pin DIN plugs at both ends.

Commodore Serial Cable 1541 Pin Out Description SP-12 PinOut 1 Serial Service Request In 1 2 Ground 2 3 Attention 3 4 Clock 4 5 Data 5 6 Reset 6