/* Imported from Wayback Machine Original URL : https://www.retrobrewcomputers.org/doku.php?id=builderpages:plasmo:p90mb Snapshot date: 2024-03-08 Generator : wayback-archiver */ ==== Table of Contents ==== [[#p90mb_p90ce201_motherboard|P90MB, P90CE201 Motherboard]] [[#introduction|Introduction]] [[#features|Features]] [[#design_information|Design Information]] [[#engineering_change|Engineering Change]] [[#software|Software]] [[#documentation|Documentation]] [[#works_to_be_done|Works to be done]] ====== P90MB, P90CE201 Motherboard ====== ===== Introduction ===== P90MB is a motherboard based on P90CE201 with 3 RC2014-like expansion slots. [[https://www.retrobrewcomputers.org/lib/exe/fetch.php?tok=63436c&media=https://www.retrobrewcomputers.org/lib/plugins/ckgedit/fckeditor/userfiles/image/builderpages/plasmo/p90mb/dsc_55070106.jpg|{{https://www.retrobrewcomputers.org/lib/exe/fetch.php?w=600&h=394&tok=d0ee9d&media=https%3A%2F%2Fwww.retrobrewcomputers.org%2Flib%2Fplugins%2Fckgedit%2Ffckeditor%2Fuserfiles%2Fimage%2Fbuilderpages%2Fplasmo%2Fp90mb%2Fdsc_55070106.jpg?600x394|www.retrobrewcomputers.org_lib_plugins_ckgedit_fckeditor_userfiles_image_builderpages_plasmo_p90mb_dsc_55070106.jpg}}]] ===== Features ===== P90CE201 at 24MHz 512K PROM 512K RAM EPM7032S CPLD Compact flash interface I2C connectors Three RC2014-like expansion slots CP/M68K ready [[https://www.retrobrewcomputers.org/lib/exe/fetch.php?tok=ba9ce2&media=https://www.retrobrewcomputers.org/lib/plugins/ckgedit/fckeditor/userfiles/image/builderpages/plasmo/p90mb/p90mb_r0_connector.jpg|{{https://www.retrobrewcomputers.org/lib/exe/fetch.php?w=500&h=328&tok=52a870&media=https%3A%2F%2Fwww.retrobrewcomputers.org%2Flib%2Fplugins%2Fckgedit%2Ffckeditor%2Fuserfiles%2Fimage%2Fbuilderpages%2Fplasmo%2Fp90mb%2Fp90mb_r0_connector.jpg?500x328|www.retrobrewcomputers.org_lib_plugins_ckgedit_fckeditor_userfiles_image_builderpages_plasmo_p90mb_p90mb_r0_connector.jpg}}]] ===== Design Information ===== [[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=builderpages:plasmo:p90mb:p90mb_scm_r0.pdf|Schematic]] Gerber [[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=builderpages:plasmo:p90mb:p90mb_r0.zip|photoplot]] [[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=builderpages:plasmo:p90mb:bill_of_materials_for_p90mb_r0.pdf|Bill of Materials]] ==== Engineering Change ==== A engineering change is required for more reliable CF access. The 8 data pins (pins 3, 5, 7, 9, 11, 13, 15, 17) to the CF adapter are removed and replaced with 8 100 ohm resistors. Similarly the IORD pin (pin 25) of the CF adapter is removed and replaced with a 100 ohm resistor. Even with the engineering change, it will not work with all CF disks. The CF disk that seems to work reliably is CISCO 64 Meg CF disk. [[https://www.retrobrewcomputers.org/lib/exe/fetch.php?tok=ce0e80&media=https://www.retrobrewcomputers.org/lib/plugins/ckgedit/fckeditor/userfiles/image/builderpages/plasmo/p90mb/dsc_54990104.jpg|{{https://www.retrobrewcomputers.org/lib/exe/fetch.php?w=500&h=473&tok=428467&media=https%3A%2F%2Fwww.retrobrewcomputers.org%2Flib%2Fplugins%2Fckgedit%2Ffckeditor%2Fuserfiles%2Fimage%2Fbuilderpages%2Fplasmo%2Fp90mb%2Fdsc_54990104.jpg?500x473|www.retrobrewcomputers.org_lib_plugins_ckgedit_fckeditor_userfiles_image_builderpages_plasmo_p90mb_dsc_54990104.jpg}}]] [[https://www.retrobrewcomputers.org/lib/exe/fetch.php?tok=7bb4e8&media=https://www.retrobrewcomputers.org/lib/plugins/ckgedit/fckeditor/userfiles/image/builderpages/plasmo/p90mb/dsc_55020104.jpg|{{https://www.retrobrewcomputers.org/lib/exe/fetch.php?w=500&h=378&tok=59f788&media=https%3A%2F%2Fwww.retrobrewcomputers.org%2Flib%2Fplugins%2Fckgedit%2Ffckeditor%2Fuserfiles%2Fimage%2Fbuilderpages%2Fplasmo%2Fp90mb%2Fdsc_55020104.jpg?500x378|www.retrobrewcomputers.org_lib_plugins_ckgedit_fckeditor_userfiles_image_builderpages_plasmo_p90mb_dsc_55020104.jpg}}]] ==== Software ==== [[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=builderpages:plasmo:p90mb:x688loader_r1_5.zip|P90MB monitor]] CP/M68K [[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=builderpages:plasmo:p90mb:p90bios.zip|BIOS]] CP/M68K [[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=builderpages:plasmo:p90mb:distro_updated.zip|distribution files]], plus gkermit, microEmac, and BASIC compiler. Unzip and use gkermit to upload to P90MB. The console baud rate needs to change to 9600 baud for gkermit to work. Lee Davison's [[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=builderpages:plasmo:p90mb:ehbasic_for_p90mb.zip|EhBasic for P90CE201]] [[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=builderpages:plasmo:p90mb:loader1_5_ehbasic_cpm.zip|EPROM programming file]] with monitor, CP/M, and EhBasic [[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=builderpages:plasmo:p90mb:lifeoled_with_2_array_51sec.zip|Conway's Game of Life]] running on P90MB. This requires a 128×64 OLED display plugged into the I2C connector. The scenerio running is “Gosper Gun”. [[https://www.retrobrewcomputers.org/lib/exe/fetch.php?tok=1df4d0&media=https://www.retrobrewcomputers.org/lib/plugins/ckgedit/fckeditor/userfiles/image/builderpages/plasmo/p90mb/game_of_life_p90mb_gosper.jpg|{{https://www.retrobrewcomputers.org/lib/exe/fetch.php?w=350&h=259&tok=83d02f&media=https%3A%2F%2Fwww.retrobrewcomputers.org%2Flib%2Fplugins%2Fckgedit%2Ffckeditor%2Fuserfiles%2Fimage%2Fbuilderpages%2Fplasmo%2Fp90mb%2Fgame_of_life_p90mb_gosper.jpg?350x259|www.retrobrewcomputers.org_lib_plugins_ckgedit_fckeditor_userfiles_image_builderpages_plasmo_p90mb_game_of_life_p90mb_gosper.jpg}}]] ===== Documentation ===== [[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=builderpages:plasmo:p90mb:p90ce201.pdf|P90CE201]] Datasheet [[builderpages:plasmo:p90mb:getting_started|Getting Started]] with P90MB ---- ===== Works to be done ===== Kermit file transfer is not working in CP/M68K. The most likely reason is because hardware handshake is required and P90CE201 UART has no hardware handshake signals. XMODEM maybe a better replacement for Kermit Kermit works at 9600 baud, so the simplest solution is to add a command to switch baud rate. CP/M68K's DDT is not working.