/* Imported from Wayback Machine
   Original URL : https://www.retrobrewcomputers.org/doku.php?id=builderpages:plasmo:zrc:zrc_rev1_1ec
   Snapshot date: 2025-12-16
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*/

==== Table of Contents ====

[[#zrc_rev11_engineering_changes|ZRC Rev1.1 Engineering Changes]]

[[#introduction|Introduction]]

[[#rts_from_zrc_to_serial_port|RTS from ZRC to serial port]]

[[#cts_from_usb-serial_adapter_to_serial_port|CTS from USB-serial adapter to serial port]]

====== ZRC Rev1.1 Engineering Changes ======

===== Introduction =====

Hardware handshake is required for xmodem file transfer for ZRC. Two engineering changes are needed to enable hardware handshake.

==== RTS from ZRC to serial port ====

The RTS function is implemented in CPLD, but a physical connection is required from CPLD's internal logic to a pin on the serial port header. A wire should be added from pin 1 of the serial header (pin 1 is a square pad) to test point T10

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==== CTS from USB-serial adapter to serial port ====

A corresponding connection is needed on the USB-serial adapter to connect RTS to CTS. The existing pin 1 is connect to DTR which needs to be cut and a short wire connects pin 1 to CTS.

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