Radisys Type 2 EPC

Embedded Personal Computer (EPC) Index
EXM - EXpansion Module  

EPC-23  Manuals


Inserting an EPC into an EXM Carrier
Note: Make sure that power to your system is off. The EPC-23 is not designed to be inserted or removed from a live system.

Notice: Use of any of the files or information on this page is AT YOUR OWN RISK. If you want a guarantee on this stuff, seek out any repair / service company that supports EXM / EPC devices.

If you have any files or experience with these devices, please reach to Louis Ohland.


EPC-23 CPU (25 MHz Intel 486 SL)

Chip on left is KU82360SL, chip in center is KU80486SL-25.
SIMMs that I have seen are Toshiba THM361000ASG-80 and THM361020ASG-80

Notice the two vertical sets of solder pads for Base Memory.

H2 - Jumper for BIOS update?
H3 - solder pads

EPC-23 Base Memory  

The EPC-23 has a base memory of 0MB, 1MB or 4 MB. Base memory is soldered on.

Note: The "23-25 1MEG" has two HM514280LJP8 soldered on the EPC.

80 ns FPM SIMM,  single-sided or thin double-sided (uses TSOP packaged DRAMs)

EPC-23 Memory Amounts 
0MB Base Memory, 4MB or 8MB SIMM, max 8MB.
1MB Base Memory, 4MB or 8MB SIMM, max 9MB.
4MB Base Memory, 4MB or 8MB SIMM, max 12MB.

Floppy Types Supported
360K, 720K, 1.2 MB, 1.44MB, and 2.88 MB. BUT... If you look at the EMC-FDM, it appears to have a max 500Kbit/s transfer rate, which suggests to me that it tops out at 1.44MB floppies.

Content created and/or collected by:
Louis Ohland, Peter Wendt, William Walsh, David Beem, Tatsuo Sunagawa, Jim Shorney, Tim Clarke, Kevin Bowling, Tomáš Slavotínek, and many others.

Ardent Tool of Capitalism - MAD Edition! is maintained by Tomáš Slavotínek.
Last update: 19 Nov 2021 - Changes & Credits | Legal Info & Contact