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==== Table of Contents ====

[[#k80w_rev21_a_romwbw-capable_z80_sbc|K80W Rev2.1, A RomWBW-capable Z80 SBC]]

[[#introduction|Introduction]]

[[#features|Features]]

[[#design_files|Design Files]]

[[#romwbw_configuration|RomWBW Configuration]]

====== K80W Rev2.1, A RomWBW-capable Z80 SBC ======

===== Introduction =====

K80W is similar to K80. It is a 22MHz Z80 SBC with KIO (Z84C90) as the I/O device. It is designed to run RomWBW. The current version is rev 2.1 replacing the older [[builderpages:plasmo:k80:k80w_r1|K80W rev1]].

[[https://www.retrobrewcomputers.org/lib/exe/fetch.php?tok=1bd03c&media=https://www.retrobrewcomputers.org/lib/plugins/ckgedit/fckeditor/userfiles/image/builderpages/plasmo/k80/k80_rev2_annotated.jpg|{{https://www.retrobrewcomputers.org/lib/exe/fetch.php?w=600&h=400&tok=a5ddd1&media=https%3A%2F%2Fwww.retrobrewcomputers.org%2Flib%2Fplugins%2Fckgedit%2Ffckeditor%2Fuserfiles%2Fimage%2Fbuilderpages%2Fplasmo%2Fk80%2Fk80_rev2_annotated.jpg?600x400|www.retrobrewcomputers.org_lib_plugins_ckgedit_fckeditor_userfiles_image_builderpages_plasmo_k80_k80_rev2_annotated.jpg}}]]

===== Features =====

Z80 overclocked to 22MHz,

512KB Flash divided into 16 32KB banks,

512KB RAM divided into 16 32KB banks,

KIO, Z84C90, is the integrated I/O interface,

DS1302 Real Time Clock,

Compact Flash interface,

SD Card interface,

Designed for RomWBW,

Two 40-pin RC2014-compatible expansion slots,

100mm X 100mm, 2-layer PC board,

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

[[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=builderpages:plasmo:k80:k80w_rev2_scm.pdf|Schematic]]

[[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=builderpages:plasmo:k80:k80w_rev2_1_gerber.zip|Gerber photoplots]]

[[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=builderpages:plasmo:k80:k80rev1:k80w_r1pcb_cpld_epm7032s.zip|CPLD design files]]

Bill of Materials

==== RomWBW Configuration ====

The following modifications to RCZ80_K80W.ASM file is needed:

SDENABLE .SET TRUE ; SD: ENABLE SD CARD DISK DRIVER (SD.ASM)\\
SDMODE .SET SDMODE_PIO ; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC|MT|PIO|Z80R|USR]

\\
This is the resulting [[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=builderpages:plasmo:k80:rcz80_rev2pcb_k80w_configuration.zip|RCZ80_K80W.ASM]]

The I/O addresses for SDMODE_PIO is hardwired to $69. It is necessary to modify SD.ASM in HBIOS as follow:

SD_IOBASE .EQU $82 ; IO BASE ADDRESS FOR SD INTERFACE

SD_DDR .EQU $83 ; DATA DIRECTION REGISTER

This is the resulting [[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=builderpages:plasmo:k80:rcz80_k80w_rev2pcb_rom.zip|ROM binary file]] for SST39SF040 that recognizes SD card connected to PIO: