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Steven Hugg 2019-09-02 20:35:46 -04:00
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`include "cpu6502.v"
`include "font_cp437_8x8.v"
// https://www.applefritter.com/replica/chapter7
// https://github.com/mamedev/mame/blob/master/src/mame/drivers/apple1.cpp
// https://github.com/jefftranter/6502/blob/master/asm/wozmon/wozmon.s
// https://www.applefritter.com/files/signetics2513.pdf
// http://retro.hansotten.nl/uploads/6502docs/signetics2504.pdf
// http://retro.hansotten.nl/uploads/6502docs/signetics2519.pdf
/**
Mango One
A 6502 computer inspired by Steve Wozniak's Apple I design
Memory map:
$0000 $0FFF RAM
$A000 $CFFF Expansion ROM
$D010 $D013 6821 PIA (keyboard, terminal)
$E000 $EFFF Integer BASIC
$FF00 $FFFF Woz Monitor, CPU vectors
$D010 Read ASCII character from keyboard.
If high bit is set then a key has been pressed.
$D011 Writing to this address clears the high bit of $D010.
The CPU usually does this after reading a key.
$D012 Writes a character to the terminal.
On read, if high bit is set then the display
is not ready to receive characters.
MangoMon commands:
R aaaa - dump memory at $aaaa
Enter - dump next 8 bytes
W aaaa bb - write memory $bb at $aaaa
G aaaa - jump to address $aaaa
https://www.applefritter.com/replica/chapter7
https://github.com/mamedev/mame/blob/master/src/mame/drivers/apple1.cpp
https://github.com/jefftranter/6502/blob/master/asm/wozmon/wozmon.s
https://www.applefritter.com/files/signetics2513.pdf
http://retro.hansotten.nl/uploads/6502docs/signetics2504.pdf
http://retro.hansotten.nl/uploads/6502docs/signetics2519.pdf
*/
module signetics_term(clk, reset, hpos, vpos, tready, dot, te, ti);