pcjs/notes.md

Git "Cheat Sheet"

Committing files

To automatically stage files that have been modified and deleted, include -a; eg:

git commit -a

Creating a new branch ("386dev")

You could use git branch, but if you've already modified some files that you now want to move to a new branch:

git checkout -b 386dev

Pushing a new branch ("386dev")

Since a simple git push will report:

fatal: The current branch 386dev has no upstream branch.
To push the current branch and set the remote as upstream, use

    git push --set-upstream origin 386dev

do what it recommends (-u is shorthand for --set-upstream):

git push -u origin 386dev

Reverting (resetting) a single file [link]

If you have an uncommitted change (it's only in your working copy) that you wish to revert (in SVN terms) to the copy in your latest commit, do the following:

git checkout filename

This will checkout the file from HEAD, overwriting your change. This command is also used to checkout branches, and you could happen to have a file with the same name as a branch. All is not lost, you will simply need to type:

git checkout -- filename

You can also do this with files from other branches, and such. man git-checkout has the details.

The rest of the Internet will tell you to use git reset --hard, but this resets all uncommitted changes you’ve made in your working copy. Type this with care.

Amending a commit

Sometimes I'm too quick with the "Commit and Push" button, and I've left a stale comment in the comment field. To correct that:

git commit --amend -m "New comment"

Unfortunately, updating the remote is not as simple as git push, which will complain:

Updates were rejected because the tip of your current branch is behind its remote counterpart.
Integrate the remote changes (e.g. 'git pull ...') before pushing again.

But in this case, there's nothing to pull, so force the push (this example assumes the current branch is master):

git push -f origin master

Node "Cheat Sheet"

Installing Node (and NPM)

I downloaded the latest Node installation package for my MacBook from nodejs.org, which provided the usual node and npm commands. Here are the versions they reported:

[~/Sites/pcjs] node -v
v0.10.26
[~/Sites/pcjs] npm -v
1.4.3

I also installed a Node helper on my MacBook called n that makes it easy to keep Node up-to-date, per this tip on stackoverflow:

1. Clear NPM's cache:

   [~/Sites/pcjs] sudo npm cache clean -f

2. Install a little helper called 'n':

   [~/Sites/pcjs] sudo npm install -g n

3. Install latest stable NodeJS version:

   [~/Sites/pcjs] sudo n stable

Alternatively pick a specific version and install like so:

[~/Sites/pcjs] sudo n 0.8.20

I'm not sure I like the generic name for this command ("n"); what would have been wrong with "node-update" or "update-node"? Oh well.

Next, I wanted to make sure npm was up-to-date. According to FAQ on npmjs.org, that's as easy as:

[~/Sites/pcjs] sudo npm update npm -g

although occasionally npm won't be able to update itself, in which case the fallback is:

[~/Sites/pcjs] curl https://npmjs.org/install.sh | sh

So, I made sure npm itself, along with n and all my other globally installed packages, were up-to-date, and then I used n to make sure I was running the latest stable version of Node:

[~/Sites/pcjs] sudo npm update -g
[~/Sites/pcjs] sudo n stable
[~/Sites/pcjs] node -v
v0.10.26

I've also seen suggestions to run this command before the preceding commands, but I don't know how often this is recommended:

[~/Sites/pcjs] sudo npm cache clean -f

Next, I ran npm init:

[~/Sites/pcjs] npm adduser
Username: jeffpar
Password: 
Email: (this IS public) jeff@pcjs.org
npm http PUT http://registry.npmjs.org/-/user/org.couchdb.user:jeffpar
npm http 201 http://registry.npmjs.org/-/user/org.couchdb.user:jeffpar

[~/Sites/pcjs] npm init
This utility will walk you through creating a package.json file.
It only covers the most common items, and tries to guess sane defaults.

See `npm help json` for definitive documentation on these fields
and exactly what they do.

Use `npm install <pkg> --save` afterwards to install a package and
save it as a dependency in the package.json file.

Press ^C at any time to quit.
name: (pcjs)
version: (0.0.0) 0.1.0
description: Node-enabled version of PCjs
entry point: (server.js)
test command:
git repository: (git://github.com/jeffpar/pcjs.git)
keywords: pcjs,ibm pc,emulator
author: Jeff Parsons <Jeff@pcjs.org>
license: (ISC)
About to write to /Users/Jeff/Sites/pcjs/package.json:

{
  "name": "pcjs",
  "version": "0.1.0",
  "description": "Node-enabled version of PCjs",
  "main": "server.js",
  "directories": {
	"doc": "docs",
	"test": "tests"
  },
  "scripts": {
	"test": "echo \"Error: no test specified\" && exit 1"
  },
  "repository": {
	"type": "git",
	"url": "git://github.com/jeffpar/pcjs.git"
  },
  "keywords": [
	"pcjs",
	"ibm",
	"pc",
	"emulator"
  ],
  "author": "Jeff Parsons <Jeff@pcjs.org>",
  "license": "ISC",
  "bugs": {
	"url": "https://github.com/jeffpar/pcjs/issues"
  },
  "homepage": "http://www.pcjs.org/"
}

Is this ok? (yes)

Next, I installed express using npm install --save express:

[~/Sites/pcjs] npm install --save express
npm http GET http://registry.npmjs.org/express
...
express@3.4.8 node_modules/express
├── methods@0.1.0
├── merge-descriptors@0.0.1
├── range-parser@0.0.4
├── cookie-signature@1.0.1
├── fresh@0.2.0
├── debug@0.7.4
├── buffer-crc32@0.2.1
├── cookie@0.1.0
├── mkdirp@0.3.5
├── commander@1.3.2 (keypress@0.1.0)
├── send@0.1.4 (mime@1.2.11)
└── connect@2.12.0 (uid2@0.0.3, pause@0.0.1, qs@0.6.6, bytes@0.2.1, raw-body@1.1.2, batch@0.5.0, negotiator@0.3.0, multiparty@2.2.0)

This added the following lines to my "package.json" file:

  "dependencies": {
	"express": "~3.4.8"
  }

Then I created a test "server.js" in the root of the project:

var http = require("http");
var express = require("express");
var app = express();
app.get("/", function(req, res) {
	res.end("Testing");
});
http.createServer(app).listen(3000);

and ran node server.js and verified that all was working as expected.

Updating Node (and NPM)

So as per above, I ran:

[~/Sites/pcjs] sudo n stable

which reported:

  install : v0.12.1
    mkdir : /usr/local/n/versions/0.12.1
    fetch : http://nodejs.org/dist/v0.12.1/node-v0.12.1-darwin-x64.tar.gz
installed : v0.12.1

Unfortunately, I ran into a regression on OS X with Node v0.12.x that affects the command-line version of PCjs (specifically, the Node REPL), so I had to revert to v0.11.11.

Next, to update NPM:

[~/Sites/pcjs] sudo npm -g install npm@latest

Connecting to a VMware Fusion Serial Port

Step 1: Add a custom serial port to a VM, by appending the following lines to its .vmx file; eg:

serial0.present = "TRUE"
serial0.fileType = "pipe"
serial0.yieldOnMsrRead = "TRUE"
serial0.startConnected = "TRUE"
serial0.fileName = "/tmp/serial0"

If this is the VM's first serial port, then it should appear as COM1. If the VM is running Windows 95, add the following to its system.ini:

[386Enh]
device=wdeb386.exe
device=debugcmd.vxd
LoadDebugOnlyObjs=Yes
debugcmd=y /n
debugcom=1
debugbaud=9600
debugsym=dos386.sym vmm.sym
debugsym=krnl386.sym gdif.sym userf.sym kernel32.sym gdi32.sym user32.sym

Step 2: Run netcat (aka nc on OS X):

stty raw && nc -U /tmp/serial0

Alternatively, you can run socat instead of netcat:

socat -d -d UNIX-CONNECT:/tmp/serial0 PTY

which will report:

PTY is /dev/ttys002

indicating the name of serial device to connect to:

screen /dev/ttys002

The advantage of using nc is that no "middle man" is required: your terminal window will be connected directly to the virtual serial port. And nc is included with OS X, whereas socat must installed separately (see http://www.dest-unreach.org/socat/).