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==== Table of Contents ====

[[#tiny68k_68000_sbc_rev_2|Tiny68K, 68000 SBC, Rev 2]]

[[#introduction|Introduction]]

[[#rev_2_design_files|Rev 2 Design Files]]

[[#board_build_procedures|Board build procedures]]

====== Tiny68K, 68000 SBC, Rev 2 ======

This page only contains updated information specific to rev 2 pc board. For general description of Tiny68K, please refer to [[boards:sbc:tiny68k|this page]].

===== Introduction =====

Tiny68K is a high-performance yet low-cost single board computer based on the Motorola 68000. Revision 2 of Tiny68K has the following changes:

The Compact Flash interface of rev 1 is marginal. It may not work with faster CF drives due to ground noises generated by faster CF drives. Rev 2 design added isolation resistors to the data line, RC circuitry to the nIORD control line, and pull up resistors to the upper half of the 16-bit data line

A 'warm boot' button is added that will generate a non-maskable interrupt to the 68000 when pressed.

Add a real-time clock based on DS1302 that is backed up with a super capacitor.

Figure below shows an assembled rev 2 Tiny68K with annotations showing the changes from rev1 design.

[[https://www.retrobrewcomputers.org/lib/exe/fetch.php?tok=de4d25&media=https://www.retrobrewcomputers.org/lib/plugins/ckgedit/fckeditor/userfiles/image/boards/sbc/tiny68k/tiny68k_rev2/tiny68k-rev2_changes_copy.jpg|{{https://retrobrewcomputers.org/lib/exe/fetch.php?w=600&h=371&tok=3c8f57&media=https%3A%2F%2Fwww.retrobrewcomputers.org%2Flib%2Fplugins%2Fckgedit%2Ffckeditor%2Fuserfiles%2Fimage%2Fboards%2Fsbc%2Ftiny68k%2Ftiny68k_rev2%2Ftiny68k-rev2_changes_copy.jpg?600x371|www.retrobrewcomputers.org_lib_plugins_ckgedit_fckeditor_userfiles_image_boards_sbc_tiny68k_tiny68k_rev2_tiny68k-rev2_changes_copy.jpg}}]]

===== Rev 2 Design Files =====

[[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:tiny68k:tiny68k_rev2:tiny68k_scm_rev2.pdf|schematic,]] the schematic and board layout tools are IVEX's WinBoard and WinDraft (ver 2.05)

gerber [[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:tiny68k:tiny68k_rev2:tiny68k_r2.zip|photo plots]], pc boards were manufactured by SeeedStudio

Part list

Altera EPM7128 [[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:tiny68k:tiny68k_rev2:rtc_en_0_wait.zip|design files]]. Designs are created in Quartus 8.1, should be compatible with later version of Quartus. Designs are entirely in schematics. [[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:tiny68k:tiny68k_rev2:tiny68k_cpld_rtc_en_0_wait.pdf|Schematic]] in PDF format. [[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:tiny68k:tiny68k_rev2:tiny68k_cpld_program_binary.zip|Programming binary]] in .pof format.

Tiny68K [[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:tiny68k:tiny68k_rev2:t68kbug_r07.zip|Monitor debugger]]. The software is developed in the EASy68K tool chain. File with .bin extension is the programming binary for serial EEPROM programmer (CH341).

===== Board build procedures =====