~crc_/ngata#1: 
determine hardware requirements

ngata is being built to run retro. we hope to eventually support multiple underlying hardware systems, though this isn't guaranteed.

we need to decide on the basic requirements and then identify one or more starting points.

Status
REPORTED
Submitter
~crc_
Assigned to
No-one
Submitted
1 year, 1 month ago
Updated
1 year, 1 month ago
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~crc_ 1 year, 1 month ago

board cpu ram flash eeprom pins voltage url
teensy 4.1 cortex m7 1mb (512k?) 8mb 4k 42 3.3v https://www.pjrc.com/store/teensy41.html
teensy 4.0 cortex m7 1mb (512k?) 2mb 4k 28 3.3v https://www.pjrc.com/store/teensy40.html

512k onboard gives enough space for about 96k cells w/256 cells per data stack. this is enough to host a full retro system (~15-20k) with plenty of space for user code.

the teensy looks like a good starting point. it's fast, has plenty of flash and ram, and a decent number of i/o connections.

we are currently looking at implementing a chorded input using a 4x3 or 4x4 grid. this would facilitate one handed input.

primary display: character lcd, as large as possible. currently hoping to do 4x20, 2x40, or 4x40 at a minimum.

secondary display: oled, 128x64 pixels

other: i would like to support some type of printer

future expansion: i intend to expose physical i/o pins via some interface. in the initial prototype, this is likely to use rj45 connections, with external devices being dongles. this would provide 6 lines of communication, plus power and ground. longer term, i would like to craft a pcb for device bridging, this should also expose an edge connector.


target cost: $200 or less per unit

i need this to be inexpensive enough for those who want one to be able to source & build at a reasonable cost. ideally it'll be possible to build one and have a set of spare parts for repairs/replacements for under $200

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