Getting started with PCM hammer

[JHSimpson]

Assembler is a long way from C#.

[JHSimpson]

Do you need assembler to solve time critical issues?

[Gampy]

The PCMHammer Application is written in C# ...

However, how this all works is PCMHammer is the PC side application, then we put a 'Kernel' aboard the PCM that takes over control of the PCM, that 'Kernel' and PCMHammer work together to Read/Write the PCM.

PCMHammer's original Kernel is written in C, it's big, like 7890 bytes, so big it won't fit in RAM of some PCM's so we needed a smaller kernel, and some PCM's only allow a single packet upload to the PCM before we get a Kernel aboard.

So we needed what we are calling a 'Loader' Kernel, a tiny (< 1024 bytes) Kernel that we put aboard the PCM, then use it to receive a larger multi packet Kernel.

Some time back I took some old code that Antus posted and started teaching myself m68k (Motorola 68000 series MCU) assembly, I got it reading PCM's that we previously couldn't read because of the C Kernel size.

This enticed Antus to join my project and he took it to another level, he whipped up the CRC code and the Mode36 code, mode36 is sending data to the PCM to be written to either RAM or Flash and then can Execute that code ...

Now we have the Loader Kernel we've been needing ... And pretty solid m68k assembly Read Only Kernels, they are tiny (Loader=~647 bytes, Kernel=~1171 bytes) compared to the C Kernels as to be expected.

Now we want to grow this assembly Kernel into a full write Kernel.

We are currently taking a short break while the assembly read Kernel and Loader Kernel get some public testing to ensure they are solid.

Then we are going to add write support ...

Antus is light years ahead of me in assembly, I am a green beginner.

If you can lend a helping hand, it would be greatly appreciated by many!

Do you Git ??
(Git, Github, is a distributed version control system)

BTW, PCMHammer source is here: PCM Hacks Repository
If you look in the Kernels directory you will see two .S files, Loader.S, and Kernel.S they are the new m68k assembler Loader and Kernel.

-Enjoy

[JHSimpson]

Oh, I see... I'll take a look at the M68K stuff to see if I can figure out what it is doing... More Later.
Jim

[JHSimpson]

OH, and yes, I use GitHub.

[antus]

develop branch is where all the latest code is, with the actual development happening on our own branches.

[Gampy]

OH, and yes, I use GitHub.

Welp, create a fork, pull a clone, create a branch and jump in ...

Lots to be done!

Always interested in seeing new views.

-Enjoy

[JHSimpson]

I guess any architecture documents you may have are in Git? What cross-assembler are you using? I need to find a M68K PRM too as I'm not familiar with that processor.

[antus]

the assembler is listed in the readme at https://github.com/LegacyNsfw/PcmHacks/ ... op/Kernels and must be installed to the default path on windows. There isnt any architecture documents that im aware of, we just try to follow standard styles, document the code in comments, and learn from our own experimentation and reverse engineering work as we go.

[JHSimpson]

Thanks! Sounds like fun!