Original URL : https://retrobrewcomputers.org/doku.php?id=boards:sbc:sbc-386ex:rev2.0
 Snapshot date: 2025-10-15
 Generator    : wayback-archiver

Disclaimer: as of the end of 2018, the BIOS ROM is still a work in progress.

N.B.: The 2.0 board requires a 1-wire update (see section below).

386EX User's Manual]] ==== Features ==== 80386EX CPU running at 25Mhz or 33Mhz FPU socket for 387SX Serial I/O using CPU integrated 8250A DS1302 RTC and NVRAM 32Kb SRAM 72-pin DRAM supports 4Mb .. 64Mb IDE interface micro SD socket ROM socket for 64Kb .. 256Kb BIOS chip All of the on chip features of the -EX chip ==== Photos ==== [[https://www.retrobrewcomputers.org/lib/exe/fetch.php?tok=64285d&media=https://www.retrobrewcomputers.org/lib/plugins/ckgedit/fckeditor/userfiles/image/boards/sbc/sbc-386ex/dan_werner_sbc386ex2_board-sm.jpg|{{https://www.retrobrewcomputers.org/lib/plugins/ckgedit/fckeditor/userfiles/image/boards/sbc/sbc-386ex/dan_werner_sbc386ex2_board-sm.jpg?801x509|www.retrobrewcomputers.org_lib_plugins_ckgedit_fckeditor_userfiles_image_boards_sbc_sbc-386ex_dan_werner_sbc386ex2_board-sm.jpg]]

Photo 1. Dan's board using the CPU mounted on a daughterboard.

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[[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:sbc-386ex:update-2018-02-18.txt|update-2018-02-18.txt]] |432b |2018-Feb-18 | |[[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:sbc-386ex:sbc-386ex-2.0-sch.pdf|sbc-386ex-2.0-sch.pdf]] |499kb|2018-Jan-21 | |[[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:sbc-386ex:sbc-386ex-2.0-pcb.pdf|sbc-386ex-2.0-pcb.pdf]] |850kb|2018-Jan-21 | |[[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:sbc-386ex:pld-386ex-2018-02-18.zip|pld-386ex-2018-02-18.zip]]|4kb |2018-Feb-18 | |[[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:sbc-386ex:sbc-386ex-2.0-kicad.zip|sbc-386ex-2.0-kicad.zip]] |1.4mb|2018-Jan-23 | |[[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:sbc-386ex:sbc-386ex-2-gerber.zip|sbc-386ex-2-gerber.zip]] |955kb|2018-Jan-21 | There is a [[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:sbc-386ex:sbc386ex2-schematic-guide.pdf|Guide to the Schematic]] which may be of interest to some builders. The current Kicad tools do not produce a very pretty [[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:sbc-386ex:sbc-386ex-2.csv_grouped_by_value.txt|Bill of Materials]]. This “CSV” (comma separated values) is edited to add additional information. [[https://www.retrobrewcomputers.org/lib/exe/fetch.php?tok=cd7192&media=https://www.retrobrewcomputers.org/lib/plugins/ckgedit/fckeditor/userfiles/image/boards/sbc/sbc-386ex/jrc-386ex-2.0-to-2.1-update-img_1078.jpg|{{https://www.retrobrewcomputers.org/lib/plugins/ckgedit/fckeditor/userfiles/image/boards/sbc/sbc-386ex/jrc-386ex-2.0-to-2.1-update-img_1078.jpg?600x450|www.retrobrewcomputers.org_lib_plugins_ckgedit_fckeditor_userfiles_image_boards_sbc_sbc-386ex_jrc-386ex-2.0-to-2.1-update-img_1078.jpg]]Board 2.0 to 2.1 (mandatory) update.

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Note: This adapter is not for other PQFP-132 chips. Power and Ground connections are specific to the 80386EX chip.

The software for the SBC-386EX has been developed under Windows using:

The Netwide assembler, NASM 2.08

Open Watcom 1.9 (2.0 should not be used)

In addition, certain tools, largely derived from the SBC-188 project will also be required: tools-2018-03-14.zip

Proper operation of the DRAM should be confirmed with: test1-2018-04-23.zip

The ROM images are distributed as *.HEX files in the archive. (Intel Hex)