What are the specs for Sample RAM (SIMMs) for my K2500/X/R/S?
Single In-Line Memory Modules, commonly referred to by the acronym "SIMM", are the small memory cards that are used for Sample RAM in the K2500 series instruments. SIMMs for the K2500 must be installed by an authorized service center.
IMPORTANT: Do not use composite SIMMs in any Kurzweil instrument. A composite SIMM is one that uses a PAL or other additional circuitry to make multiple DRAM chips act like bigger chips. Non-composite SIMMs (acceptable) have no chips other than DRAM memory chips soldered to the board. SIMMs with PALs, buffers, or other logic components will not work in a K2500; do not use them. Composite SIMMs may appear to work in some cases, but they will be unreliable.
Over its years in production, the K2500 used two different SIMM styles. Early K2500 models take up to eight 30- pin SIMMs; K2500s with a rev. K or later mother board take up to two 72-pin SIMMs.
To determine the SIMM requirements of a K2500 without disassembling the unit, check its serial number; a "Z" as the seventh character (e.g., 479501Z00001) indicates that the K2500 has a rev. K or later mother board and requires 72-pin SIMMs. K2500s with a "0" as the seventh character of the serial number use 30-pin SIMMs.
SIMMs for K2500s with 30-pin sockets (w/ mother boards earlier than rev. K)
K2500's support up to 128MB of sample RAM in eight paired slots. They must be installed by an authorized service center. SIMMs must meet the following specs:
SIMMs for K2500s with 72-pin sockets (w/ rev. K or later mother boards)
K2500's support up to 128MB of sample RAM in two slots. They must be installed by an authorized service center. SIMMs must meet the following specs:
Although K2500s with rev. K or later mother boards have two SIMM sockets, some SIMMs cannot be paired with other SIMMs, whether of the same or a different size. The table below shows the acceptable 72-pin SIMM configurations, and indicates which sizes can be combined.
|Size||Configuration||Pair with other SIMMs?|
|4 Mb||1Mx32 or 1Mx36||Yes|
|8 Mb||2Mx32 or 2Mx36||No|
|16 Mb||4Mx32 or 4Mx36||Yes|
|32 Mb||8Mx32 or 8Mx36||No|
|64 Mb||16Mx32 or 16Mx36||Yes|
|128 Mb||32Mx32 or 32Mx36||No|
For example, a 4 MB SIMM can be combined with another 4 MB SIMM to create 8 MB of sample memory. Similarly, a 4 MB SIMM could be paired with a 16 MB or 64 MB SIMM. It could not, however, be paired with an 8 MB, 32 MB or 128 MB SIMM. If you use an 8 MB, 32 MB, or 128 MB SIMM you cannot use the other SIMM socket.
For a list of companies that make SIMMs which we know work correctly, please see our Developers List. (Other companies may also have proper SIMMs).
Need more info? Check out the following links: