/* Imported from Wayback Machine
   Original URL : https://www.retrobrewcomputers.org/doku.php?id=builderpages:plasmo:frr512k:rev0:mb020combo
   Snapshot date: 2025-03-15
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*/

==== Table of Contents ====

[[#combination_board_for_mb020|Combination Board for MB020]]

[[#introduction|Introduction]]

[[#features|Features]]

[[#design_files|Design Files]]

[[#software|Software]]

====== Combination Board for MB020 ======

===== Introduction =====

FRR512K is modified to serve as the combination board for [[builderpages:plasmo:mb020|MB020]]. The combination board implements the serial port, bootstrap ROM, and compact flash drive functions.

[[https://www.retrobrewcomputers.org/lib/exe/fetch.php?tok=d63de2&media=https://www.retrobrewcomputers.org/lib/plugins/ckgedit/fckeditor/userfiles/image/builderpages/plasmo/frr512k/rev0/dsc_66991215.jpg|{{https://www.retrobrewcomputers.org/lib/exe/fetch.php?w=600&h=238&tok=355d7c&media=https%3A%2F%2Fwww.retrobrewcomputers.org%2Flib%2Fplugins%2Fckgedit%2Ffckeditor%2Fuserfiles%2Fimage%2Fbuilderpages%2Fplasmo%2Ffrr512k%2Frev0%2Fdsc_66991215.jpg?600x238|www.retrobrewcomputers.org_lib_plugins_ckgedit_fckeditor_userfiles_image_builderpages_plasmo_frr512k_rev0_dsc_66991215.jpg}}]]

[[https://www.retrobrewcomputers.org/lib/exe/fetch.php?tok=4de185&media=https://www.retrobrewcomputers.org/lib/plugins/ckgedit/fckeditor/userfiles/image/builderpages/plasmo/frr512k/rev0/dsc_67001215.jpg|{{https://www.retrobrewcomputers.org/lib/exe/fetch.php?w=500&h=207&tok=892264&media=https%3A%2F%2Fwww.retrobrewcomputers.org%2Flib%2Fplugins%2Fckgedit%2Ffckeditor%2Fuserfiles%2Fimage%2Fbuilderpages%2Fplasmo%2Ffrr512k%2Frev0%2Fdsc_67001215.jpg?500x207|www.retrobrewcomputers.org_lib_plugins_ckgedit_fckeditor_userfiles_image_builderpages_plasmo_frr512k_rev0_dsc_67001215.jpg}}]]

===== Features =====

Repurposed [[builderpages:plasmo:frr512k:rev0|FRR512K]] board

64KB bootstrap EPROM for MB020

Compact flash drive

Serial port with setting of 115200, N81 with hardware handshake

Design to run CP/M68K on [[builderpages:plasmo:mb020|MB020]]

===== Design Files =====

Schematic

Engineering Changes

[[https://www.retrobrewcomputers.org/lib/exe/fetch.php?tok=a3b6bb&media=https://www.retrobrewcomputers.org/lib/plugins/ckgedit/fckeditor/userfiles/image/builderpages/plasmo/frr512k/rev0/frr512k_combo_mb020.jpg|{{https://www.retrobrewcomputers.org/lib/exe/fetch.php?w=300&h=389&tok=2e5409&media=https%3A%2F%2Fwww.retrobrewcomputers.org%2Flib%2Fplugins%2Fckgedit%2Ffckeditor%2Fuserfiles%2Fimage%2Fbuilderpages%2Fplasmo%2Ffrr512k%2Frev0%2Ffrr512k_combo_mb020.jpg?300x389|www.retrobrewcomputers.org_lib_plugins_ckgedit_fckeditor_userfiles_image_builderpages_plasmo_frr512k_rev0_frr512k_combo_mb020.jpg}}]]

[[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=builderpages:plasmo:frr512k:rev0:frr512k_r0_combo_cpld_mb020.zip|CPLD design files]]

==== Software ====

[[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=builderpages:plasmo:frr512k:rev0:eprom_combo_mb020.zip|Bootstrap EPROM]] for MB020

[[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=builderpages:plasmo:frr512k:rev0:cpm_for_frr512k_combo_mb020.zip|CP/M68K]] for combo. The three files included need to be loaded; type “go 15000” afterward.