[torontocbm] Re: Adventures in C64 Rom Replacement...

  • From: Ernie Chorny <chorny@xxxxxxxxxxxx>
  • To: torontocbm@xxxxxxxxxxxxx
  • Date: Tue, 05 May 2009 18:02:34 -0400

Hi -
I've done a little work with EPROMs back in the early nineties - changing the bootup screen colour, custom text - that sort of straightforward thing.
You mentioned putting something into the datassette space - that is where JiffyDOS goes.
What I wanted to do (but never did) was to add some commands to the monitor on the C128. For example, there is a published short ML routine for printing (to paper) your ML data. Since there is space in the C128 ROM it doesn't seem difficult to add the code and have the system recognize the command to do so. Also it would be interesting to implement the 2 unimplemented Basic 7 commands (would have to write some code here).
You mention custom kernal and basic files - as long as they are burned to the same EPROM locations (ie: in the same sequence) as the original code there shouldn't be a problem. 

Ernie


Miraglia, Walter wrote:

Howdy all,
Just thought I would share a my experience
Removing the ROM from a 64c computer…
My Commodore 64c is the kind with the kernel and Basic
On the same chip: 251913-01 and soldered down to boot (so to speak).
I got brave, and got my nippy cutters and after saying a few little prayers to myself, I went in and chopped that chip out. I wish had been more careful with the legs… 
(more on that later…)
Using the copper wick, I managed to remove the remaining portion of the legs And quite a bit of the solder… but alas, only managed to get one or two holes 
Through… kinda depressing… my solder sucker was not very useful either…
What I did find very useful was to remove the majority of the solder with the wick, Then heat up the whole and literally blow through the wholes quick and hard… I managed to clean up the holes pretty fast that way… then I soldered in my 28 pin 
IC socket, and though awesome…
I hooked up my new eprom burner up to my pc, and burned myself a new copy of the rom… Installed it and it worked…I was thrilled… I then turned my attention to the chip I butchered, And thought I should give it some life… so I soldered it down onto a 28 pin Machined ic socket, And tested it out, although it looks like Frankenstein’s monster, it did work… 
Ok I hope I haven’t lost anyone as the next part is the fun part…
The reason for this activity is that I wanted to customize my kernel,
Change the start up colours, remove the cassette area’s and use the
Space for some other purpose…(as laid out in the promos booklet for the CI prom burner….) P.S. I got a Megabit ROM for my C128, wich included the pdf manual for the c64 eprom burner, 
Which got me started on this little project…
And I was just wondering what kind of experiences folks have had doing this Sort of thing, and what kind of changes they made… and if will to perhaps exchange 
Some customizations… (if that’s possible?)
I’ve started to edit my ROM, small things so far like change the startup colour, And change the name at the top… I was just wondering if anyone has messed around with this… One other question… if I find a custom .bin file for the kernel, and a custom .bin file for the basic, can they be added 
And then put on a 27128 chip? Or would I have to change the code around?
J thanks for you attention… J
Look forward to hearing about your adventures in Rom Replacement….

Other related posts:

  1. Home
  2. torontocbm
  3. Archive
  4. 05-2009