Tandy 64 Jr.

A intro for the IBM PCJr.

Recorded from real hardware: (he, we don't have a way to capture RGBI output yet... sorry)

(The "Tandy 64" for the Tandy 1000HX is here)

Requirements

• IBM PCJr.

• Requires at least 256Kb RAM

• Install jrconfig and use with at least /v32. eg: in your config.sys add:

    device=jrconfig.sys /v32
  

How to compile it

• Install nasm
• Install alink
• (Optional) Install Python 3
• (Optional) Install DosDox-x
• (Optional) Install upx

And do:

$ make

To run it in the DosBox-x emulator, do:

$ make run

Resources

The /res folder has the music, graphics and fonts in their native formats. And in the /tools folder are the scripts to convert them to a more optimized format for the Tandy.

To convert the resources to native do:

$ make res

Source code structure

The /src folder contains the source code and all converted resources. There are 4 .asm files:

• main.asm: setups the stack and calls the pre_intro, intro and post_intro in order
• pre_intro.asm: shows the C64 loading screen
• intro.asm: Everything happens here. The code is somewhat messy. There a few state machines to control and sync the different actions. Some pointers:
  • plasma_tex_*: refers to "plasma textures", the ones that appear at the very beginning
  • plasma_*: (without the _tex suffix): refers to the plasma animation.
  • new_i08_*: there are like 3 different interrupt handlers. They are used in at different parts
  • boy_anim_*: code related to the guy walking/dancing
  • text_writter_*: code related to the "cursor writting text"
  • letter_state_*: code related to the PVM letters animation
  • state_* / main_state_*: "main" state machine code
  • scroll_*: scroller code
  • raster_bars_*: raster bar effect code
• post_intro.asm: the final C64 screen

Tools

In tools folder you will find:

• convert_vgm_to_pvm.py: Converts VGM music format to PVM (Plays VGM Music) music format
  • Almost the same as VGM but uses Run-leght encoding. As an example, the music that we use takes ~78K in VGM format, and around ~48K in PVM format. It is good to have it in less than 64k (1 segment)
  • A stand-along PVM player could be found here: pvmplay.asm
• convert_gfx_to_bios_format.py: Converts graphics to Tandy format.
• convert_anim_to_frames.py: Quick hack to dump animation frames in tandy format

We also used:

• Deflemask for composing the music
• plasma_generator.py: to visually build the plasma effects
• VChar64 for the charset
  • The charset used is based on one used on a c64 intro?? (couldn't find the original intro)
• [IBM PCJr Techinical Reference manual][https://archive.org/details/IbmPcjrTechnicalReference]
• IBM PCJr BIOS dump
  • Which is based on based on the disassembled BIOS from the Technical Reference with some comments of our own

Lessons learned

• Comming soon™

Questions and others

Do you have questions? Do you want to collaborate with PVM? We're here:

• http://pungas.space
• On IRC. EFnet . Channel #pvm
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