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====== ECB-Cassette IF ======

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|\\ Home made alu bracket for the 3.5mm jacks.\\ \\ I made both for 300 baud and checked if they could “talk” correctly to each other. (as in backup/restore).\\ \\ Turns out I had to measure&select the timing capacitor C2 very precise to get 100% reliable interchangeable operation.\\ \\ I have now “upgraded one of the board to 600baud.\\ \\ I will modify the bracket to include the send/receive activity LEDs.\\ \\ Info: This pcb has ground plane on both side so no problem with the screws.|{{https://www.retrobrewcomputers.org/lib/exe/fetch.php?w=374&h=400&tok=820c0e&media=https%3A%2F%2Fwww.retrobrewcomputers.org%2Flib%2Fplugins%2Fckgedit%2Ffckeditor%2Fuserfiles%2Fimage%2Fbuilderpages%2Fspeed3ple%2Fimages%2Fimg_20191015_174706small.jpg?374x400|ECB Cassette IF 300 and 600 baud}}                                                                                                   |
|Cassette IF in action in a backplane-4:                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |{{https://www.retrobrewcomputers.org/lib/exe/fetch.php?w=400&h=473&tok=c290a8&media=https%3A%2F%2Fwww.retrobrewcomputers.org%2Flib%2Fplugins%2Fckgedit%2Ffckeditor%2Fuserfiles%2Fimage%2Fbuilderpages%2Fspeed3ple%2Fimages%2Fimg_20200329_231926small.jpg?400x473|www.retrobrewcomputers.org_lib_plugins_ckgedit_fckeditor_userfiles_image_builderpages_speed3ple_images_img_20200329_231926small.jpg}}|
|\\ Cassette IF signal out on Scope:\\ \\ This is the “Kansas City” standard, one of several cassette formats in use at the time (mid 70's).\\ \\ Kasas City format use an continuous audio stream of a tone and shift that tone between 2400hz and 1200hz to indicate 1 or 0.\\ \\ 8 cycles of 2400hz represent a “1” bit or a MARK and\\ \\ 4 cycles of 1200hz represent a “0” bit or a SPACE.                                                                                                            |{{https://www.retrobrewcomputers.org/lib/exe/fetch.php?w=500&h=326&tok=b03266&media=https%3A%2F%2Fwww.retrobrewcomputers.org%2Flib%2Fplugins%2Fckgedit%2Ffckeditor%2Fuserfiles%2Fimage%2Fbuilderpages%2Fspeed3ple%2Fimages%2Fimg_20200329_230632small.jpg?500x326|www.retrobrewcomputers.org_lib_plugins_ckgedit_fckeditor_userfiles_image_builderpages_speed3ple_images_img_20200329_230632small.jpg}}|
|\\ Cassette Interface in use:\\ \\ To send a file to tape: **PIP PUN:=<filename.hex>[E]**\\ \\                                                                                                                                                                                                                                                                                                                                                                                                             |{{https://www.retrobrewcomputers.org/lib/exe/fetch.php?w=500&h=250&tok=a22dfd&media=https%3A%2F%2Fwww.retrobrewcomputers.org%2Flib%2Fplugins%2Fckgedit%2Ffckeditor%2Fuserfiles%2Fimage%2Fbuilderpages%2Fspeed3ple%2Fimages%2Fimg_20191013_011746small.jpg?500x250|www.retrobrewcomputers.org_lib_plugins_ckgedit_fckeditor_userfiles_image_builderpages_speed3ple_images_img_20191013_011746small.jpg}}|
|Cassette IF and technical document:                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |{{https://www.retrobrewcomputers.org/lib/exe/fetch.php?w=500&h=474&tok=6d4c55&media=https%3A%2F%2Fwww.retrobrewcomputers.org%2Flib%2Fplugins%2Fckgedit%2Ffckeditor%2Fuserfiles%2Fimage%2Fbuilderpages%2Fspeed3ple%2Fimages%2Fimg_20200405_211813small.jpg?500x474|www.retrobrewcomputers.org_lib_plugins_ckgedit_fckeditor_userfiles_image_builderpages_speed3ple_images_img_20200405_211813small.jpg}}|
|Interconnecting 2 SBC and sending/receiving data through audio cable at 300baud:                                                                                                                                                                                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                                                                       |

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