commit 9ccb0f0a7caccd11d387535e41b9dd96fc83bb4c parent b02403ec7abcf650d549fa27ee2fda010799cd5b Author: Brian Swetland <swetland@frotz.net> Date: Thu, 13 Jul 2023 15:36:55 -0700 add a readme file Diffstat:
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diff --git a/README.md b/README.md @@ -0,0 +1,44 @@ +# Apple II VGA PCB + +This is a pair of PCBs that implements a version of the Apple II VGA design. + +Please see the [Apple II VGA Project](https://github.com/markadev/AppleII-VGA) for details and firmware. + +This version differs from the original in that: +1. It makes use of the Rpi Pico's regulator for 3v3 supply +2. It allows the SYNC signal to be optionally routed to the Rpi Pico (instead of allowing Apple II bus read operations) +3. It uses a fourth 74LVC245A instead of a 74LS07 for the remaining bus signals (fewer unique components) + +The KiCAD source files are included in the [appleii.vga/](appleii.vga/) +and [appleii.vga.connector/](appleii.vga.connector/) directories. + +The [export/](export/) directory contains gerber files suitable for fabrication. +Beware that only the v1.0.2 version has been fabricated so far (at JLCPCB). +The v1.1.0 version contains some minor improvements but has not yet been +fabricated and tested. + +To use the standard firmware, install a 0 ohm resistor at R13 and leave R12 and R14 unpopulated. + + +PCBs and parts for assembly: + + + +Assembled PCBs: + + + +Installed in an Apple IIe: + + + +Lode Runner displayed on a 15" Sony Trinitron VGA monitor: + + + +Schematic and Layout for v1.1.0: + + + + +