Rounded out the PC8080 portion of the tree

devices/pc8080/machine/exerciser/README.md

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+---
+layout: page
+title: 8080 Exerciser Test Machine
+permalink: /devices/pc8080/machine/exerciser/
+redirect_from:
+  - /devices/pc8080/machine/test/
+machines:
+  - type: pc8080
+    id: test8080
+    debugger: true
+---
+
+8080 Exerciser Test Machine
+---
+
+This is a test of [PC8080](/modules/pc8080/), a new 8080-based machine emulator being added to the
+PCjs Project.
+
+The test machine below loads a copy of the
+[8080 Exerciser](https://web.archive.org/web/20151006085348/http://www.idb.me.uk/sunhillow/8080.html)
+(specifically, [8080EX1](/devices/pc8080/rom/test/8080EX1.MAC)) and intercepts the exerciser's CP/M console
+calls so that you can see its progress in the Control Panel window.  This is a "headless" test machine
+(no keyboard or display), so that's all you get.
+
+The good news: PC8080 passes all the 8080 Exerciser tests.  And it doesn't do it by using all sorts of weird
+"flags tables" that most other 8080 emulators seem to fall back on.
+
+Like all the other CPU emulations in the PCjs Project, PC8080 never "calculates" the flags unless/until they are
+actually required, which considerably speeds up all arithmetic operations.
+
+Of particular note are the 8080's subtract, compare, and decrement operations, which actually perform addition,
+not subtraction, by using two's complement arithmetic in "stages": the first stage (inverting the source operand)
+occurs *before* the addition, and the second stage (incrementing the inverted operand) occurs *after* the addition.
+And it appears to be the result of the *first* stage, not the second, that determines the state of the Auxiliary
+Carry flag (AF).
+
+At 2Mhz, the 8080 Exerciser tests take quite a while, but you can click the speed button while the machine is running
+to increase the simulated speed; it will revert to 2Mhz when you exceed the maximum speed that your system supports.
+
+NOTE: The original [8080 Exerciser website](http://www.idb.me.uk/sunhillow/8080.html) is currently unavailable,
+so we refer you to the copy on
+[archive.org](https://web.archive.org/web/20151006085348/http://www.idb.me.uk/sunhillow/8080.html).
+The 8080 Exerciser source code has also been "forked" on [GitHub](https://github.com/begoon/8080ex1).
+
+{% include machine.html id="test8080" %}
+
+8080 Online Resources
+---
+
+[8080 Opcode Map](http://pastraiser.com/cpu/i8080/i8080_opcodes.html)

devices/pc8080/machine/exerciser/machine.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<?xml-stylesheet type="text/xsl" href="/versions/pc8080/1.22.0/machine.xsl"?>
+<machine id="test8080" class="pc8080" border="1" pos="center" background="#FAEBD7">
+	<name pos="center">8080 Exerciser Test Machine</name>
+	<computer id="computer" busWidth="16"/>
+	<cpu id="cpu8080" model="8080" cycles="2000000"/>
+	<rom id="romTest" addr="0x0100" size="0x1200" file="/devices/pc8080/rom/exerciser/8080EX1.json" writable="true"/>
+	<ram id="ramTest" addr="0x1300" size="0xED00"/>
+	<panel ref="/devices/pc8080/panel/wide.xml"/>
+	<debugger id="debugger"/>
+</machine>