====== 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/plugins/ckgedit/fckeditor/userfiles/image/builderpages/plasmo/frr512k/rev0/dsc_66991215.jpg?direct&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/plugins/ckgedit/fckeditor/userfiles/image/builderpages/plasmo/frr512k/rev0/dsc_67001215.jpg?direct&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/plugins/ckgedit/fckeditor/userfiles/image/builderpages/plasmo/frr512k/rev0/frr512k_combo_mb020.jpg?direct&300x389|www.retrobrewcomputers.org_lib_plugins_ckgedit_fckeditor_userfiles_image_builderpages_plasmo_frr512k_rev0_frr512k_combo_mb020.jpg}}]]

{{:builderpages:plasmo:frr512k:rev0:frr512k_r0_combo_cpld_mb020.zip|CPLD design files}}

==== Software ====

{{:builderpages:plasmo:frr512k:rev0:eprom_combo_mb020.zip|Bootstrap EPROM}}  for MB020

{{: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.