Retro PCBs Wiki

This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong.
/* Imported from Wayback Machine
   Original URL : https://www.retrobrewcomputers.org/doku.php?id=builderpages:plasmo:protorc3:65spi_proto
   Snapshot date: 2025-09-09
   Generator    : wayback-archiver
*/

==== Table of Contents ====

[[#spi_prototype|65SPI Prototype]]

[[#introduction|Introduction]]

[[#features|Features]]

[[#design_information|Design Information]]

[[#engineering_changes|Engineering changes]]

[[#software|Software]]

[[#manuals|Manuals]]

====== 65SPI Prototype ======

===== Introduction =====

[[https://sbc.rictor.org/|Daryl Rictor's]] 65SPI design is captured in Altera Quartus schematic and prototyped with ProtoRC3. This page describes the 65SPI design in Altera schematic, its prototype, and testing.

[[https://www.retrobrewcomputers.org/lib/exe/fetch.php?tok=ef8f6d&media=https://www.retrobrewcomputers.org/lib/plugins/ckgedit/fckeditor/userfiles/image/builderpages/plasmo/protorc3/65spi_proto/dsc_63250128.jpg|{{https://www.retrobrewcomputers.org/lib/exe/fetch.php?w=600&h=470&tok=74c34e&media=https%3A%2F%2Fwww.retrobrewcomputers.org%2Flib%2Fplugins%2Fckgedit%2Ffckeditor%2Fuserfiles%2Fimage%2Fbuilderpages%2Fplasmo%2Fprotorc3%2F65spi_proto%2Fdsc_63250128.jpg?600x470|www.retrobrewcomputers.org_lib_plugins_ckgedit_fckeditor_userfiles_image_builderpages_plasmo_protorc3_65spi_proto_dsc_63250128.jpg}}]]

[[https://www.retrobrewcomputers.org/lib/exe/fetch.php?tok=70c182&media=https://www.retrobrewcomputers.org/lib/plugins/ckgedit/fckeditor/userfiles/image/builderpages/plasmo/protorc3/65spi_proto/dsc_63260128.jpg|{{https://www.retrobrewcomputers.org/lib/exe/fetch.php?w=600&h=513&tok=7d6c24&media=https%3A%2F%2Fwww.retrobrewcomputers.org%2Flib%2Fplugins%2Fckgedit%2Ffckeditor%2Fuserfiles%2Fimage%2Fbuilderpages%2Fplasmo%2Fprotorc3%2F65spi_proto%2Fdsc_63260128.jpg?600x513|www.retrobrewcomputers.org_lib_plugins_ckgedit_fckeditor_userfiles_image_builderpages_plasmo_protorc3_65spi_proto_dsc_63260128.jpg}}]]

===== Features =====

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

Schematic

[[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=builderpages:plasmo:protorc3:65spi_proto:protorc3_65spi_cpld_released.zip|CPLD design]]. In order to fit the existing ProtoRC3 pin assignments, the following I/O pins from the original 65SPI are deleted: MWR, MRD, CS2, Slave Select 3 to Slave Select 7.

==== Engineering changes ====

The followings are changes to ProtoRC3 to accommodate 25LC080 serial EEPROM

=== Data bus modifications ===

Test point T15 to D7, RC2014-34

Test point T14 to D6, RC2014-33

Test point T13 to D5, RC2014-32

Test point T12 to D4, RC2014-31

Test point T11 to D3, RC2014-30

Test point T10 to D2, RC2014-29

Test point T9 to D1, RC2014-28

Test point T8 to D0, RC2014-27

=== 25LC080 Connections ===

25LC080-1 (CS) to Test point T4

25LC080-2 (SO) to Test point T2

25LC080-3 (WP) to +5V

25LC080-4 (GND) to ground

25LC080-5 (SI) to Test point T1

25LC080-6 (SCK) to Test point T3

25LC080-7 (HOLD) to +5V

25LC080-8 (VCC) to +5V

==== Software ====

25LC080 test software

===== Manuals =====

[[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=builderpages:plasmo:protorc3:65spi_proto:25lc080.pdf|25LC080 data sheet]]