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

  • From: STEVE GRAY <sjgray@xxxxxxxxxx>
  • To: torontocbm@xxxxxxxxxxxxx
  • Date: Tue, 5 May 2009 10:08:03 -0700 (PDT)

I picked up a C16 back when it was originally released and was impressed by the 
windowing features (ESC-T to set top of window, ESC-B for bottom etc) and I 
attempted to integrate those into the C64 kernal. I also did the same as you, 
changing screen colours, startup message etc). I had it mostly complete but 
there was a bug/bugs and it would crash occasionally. Nice thing about the C64 
is you can test the code by writing to RAM under the kernal then swapping out 
the ROM, so no need to burn a new eprom each time. 

Anyway, I also have a new EPROM programmer on the way and have lots of things 
to try it on. I want to get JiffyDOS on most of my machines, and I want to burn 
an Execudesk ROM for my 8296D machine.

Steve




________________________________
From: "Miraglia, Walter" <Walter.Miraglia@xxxxxxxxxxx>
To: "torontocbm@xxxxxxxxxxxxx" <torontocbm@xxxxxxxxxxxxx>
Sent: Tuesday, May 5, 2009 11:06:48 AM
Subject: [torontocbm] Adventures in C64 Rom Replacement...

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….

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