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====== Frugal RAM/ROM 512K for RC2014, Rev0 ======

===== Introduction =====

This is a low cost RAM/ROM 512K for RC2014. It is compatible with Wayne [[https://github.com/wwarthen/RomWBW|Warthen's ROMWBW]] and also includes a CF interface as well as an I2C interface. Discussion about this board can be found here: https://groups.google.com/g/rc2014-z80/c/TvsdMFqeT9c FRR512K was first prototyped with ProtoRC3. This links to the [[builderpages:plasmo:protorc3:frr512proto:frr512k|Prototype FRR512K]].

===== Features =====

Low cost 32-macrocell CPLD

512K EPROM based on SST39SF040

512K RAM based on AS6C4008

Compact flash interface

I2C interface

Compatible with ROMWBW

[[https://www.retrobrewcomputers.org/lib/exe/fetch.php?tok=073c14&media=https://www.retrobrewcomputers.org/lib/plugins/ckgedit/fckeditor/userfiles/image/builderpages/plasmo/frr512k/dsc_65800609.jpg|{{https://www.retrobrewcomputers.org/lib/plugins/ckgedit/fckeditor/userfiles/image/builderpages/plasmo/frr512k/dsc_65800609.jpg?600x347|www.retrobrewcomputers.org_lib_plugins_ckgedit_fckeditor_userfiles_image_builderpages_plasmo_frr512k_dsc_65800609.jpg}}]]

===== Design Information =====

[[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=builderpages:plasmo:frr512k:frr512k_rev0_scm.pdf|Schematic]]

[[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=builderpages:plasmo:frr512k:frr512k_gerber_rev0.zip|Gerber photoplots]]

[[builderpages:plasmo:frr512k:rev0:ec|Engineering Change]]

==== Software ====

===== Alternative Applications =====

FRR512K has been repurposed for other applications. This section describes the various alternative applications. Discussions about the repurposed applications can be found [[https://groups.google.com/g/retro-comp/c/bt5pVneks0E/m/YE1brr5PAQAJ|here]]

==== Second Compact Flash board ====

FRR512K is partially populated to serve as the [[builderpages:plasmo:frr512k:rev0:cf2nd|second compact flash drive]].

==== MC6850 ACIA Emulation ====

FRR512K's CPLD is replaced with EPM7064SLC44 that's programmed to [[builderpages:plasmo:frr512k:rev0:emul6850|emulate a MC6850 ACIA]]

==== Combo board for MB020 ====

FRR512K is modified to serve [[builderpages:plasmo:frr512k:rev0:mb020combo|serial port, ROM, compact flash drive]] of 68020 motherboard

==== Emulation of RC2014 512K ROM/RAM board ====

The original [[https://rc2014.co.uk/modules/512k-rom-512k-ram-module/|RC2014 512K ROM/RAM]] board has 32 banks of RAM and 32 banks of ROM. FRR512K can be [[builderpages:plasmo:frr512k:rev0:emulate_512kram_rom|modified to emulate]] RC2014's 512K RAM/ROM board.