pcjs/apps/pcx86

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page	IBM PC Application Demos	/apps/pcx86/

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Creating IBM PC Application Demos

Demos in our Application Archives combine Software Application Manifests with Machine Configurations.

We'll use the VisiCalc Demo as an example. First, we choose a machine configuration. For VisiCalc, we chose a Model 5150 machine with a Monochrome Display, and then inserted a link to that machine in the demo's manifest:

<machine href="/devices/pcx86/machine/5150/mda/64kb/machine.xml"/>

Next, the manifest requires a disk image containing the VisiCalc program (VC.COM). We used the DiskDump module to create that disk image:

cd apps/pcx86/1981/visicalc
node ../../../../modules/diskdump/bin/diskdump --path="archive/VC.COM;../README.md" --format=json --output=disk.json --manifest

The DiskDump command created a disk image named "disk.json" containing two files ("VC.COM" from the "archive" subdirectory, and "README.md" from the "archive" parent directory) and automatically added that disk image to the demo's manifest:

<disk id="disk01" size="163840" chs="40:1:8" dir="archive/" href="/apps/pcx86/1981/visicalc/disk.json" md5="61494f998d5fb0e31e7b8bd99f1cc588" md5json="3ad82ed815725e6bd786f92a4714e84f">
    <file size="27520" time="1981-12-16 23:00:00" attr="0x20" md5="28997dfedb2440c6054d8be835be8634">VC.COM</file>
    <file dir="../">README.md</file>
</disk>

Now that the manifest contains a disk image, we were able to add the manifest to our set of Sample Disks:

<manifest ref="/apps/pcx86/1981/visicalc/manifest.xml" disk="*"/>

Next, we started a version of our chosen machine that's also configured to use the Debugger, by loading the following machine.xml into a web browser (it's assumed the Node web server is already running on port 8088):

http://localhost:8088/devices/pcx86/machine/5150/mda/64kb/debugger/machine.xml

Then we booted DOS, loaded the VisiCalc disk, ran VisiCalc, pressed the Debugger's "Halt" button, pressed "Clear" to clear the Debugger's output window, and typed the following Debugger command:

d state

We copied-and-pasted the entire contents of the Debugger's output window into a file named "state.json", and then updated the <machine> entry in the manifest:

<machine href="/devices/pcx86/machine/5150/mda/64kb/machine.xml" state="/apps/pcx86/1981/visicalc/state.json"/>

It's important to use a state file only with the machine configuration it was created with; in this case, we're OK, because the only difference between the two chosen Model 5150 machines is the addition of the Debugger.