Replace C64 kernal with cartridge..
Sam
a C64 with a kernal rom in a cartridge. Examples with a Jiffydos
kernal, so I can use it on every C64 without replacing the original
kernal rom. I think it must be possible, as I know that some Ultimax
catridges are overriding the internal kernal. How do I do this ?
Suggestions welcome !
Regards, SAM.
Clocky
Putting the C64 into Ultimax mode will certainly allow you to use an
external cartridge for the kernal easily but then you are limited to 4kb RAM
(IIRC) which is hardly useful.
Ruud Baltissen drew up a schematic for a kernal cartridge that works around
this problem, but as I understand it the schematic is theoretical and hasn't
been realised in hardware.
Clocky
> Sam wrote:
>> I was wondering if it is possible to replace the internal cartridge
>> of a C64 with a kernal rom in a cartridge. Examples with a Jiffydos
>> kernal, so I can use it on every C64 without replacing the original
>> kernal rom. I think it must be possible, as I know that some Ultimax
>> catridges are overriding the internal kernal. How do I do this ?
>> Suggestions welcome !
>>
>> Regards, SAM.
>
> Putting the C64 into Ultimax mode will certainly allow you to use an
> external cartridge for the kernal easily but then you are limited to
> 4kb RAM (IIRC) which is hardly useful.
>
> Ruud Baltissen drew up a schematic for a kernal cartridge that works
> around this problem, but as I understand it the schematic is
> theoretical and hasn't been realised in hardware.
>
Hmmm, OE had a brainfart, let's try that again...
http://zimmers.net/anonftp/pub/cbm/documents/projects/other/c64-kernal-cartridge.gif
Clocky
> Sam wrote:
>> I was wondering if it is possible to replace the internal cartridge
>> of a C64 with a kernal rom in a cartridge. Examples with a Jiffydos
>> kernal, so I can use it on every C64 without replacing the original
>> kernal rom. I think it must be possible, as I know that some Ultimax
>> catridges are overriding the internal kernal. How do I do this ?
>> Suggestions welcome !
>>
>> Regards, SAM.
>
> Putting the C64 into Ultimax mode will certainly allow you to use an
> external cartridge for the kernal easily but then you are limited to
> 4kb RAM (IIRC) which is hardly useful.
>
> Ruud Baltissen drew up a schematic for a kernal cartridge that works
> around this problem, but as I understand it the schematic is
> theoretical and hasn't been realised in hardware.
>
>
Sorry if these posts repeat themselves, I had some issues with OE.
Try these links instead.
http://zimmers.net/anonftp/pub/cbm/documents/projects/other/c64-kernal-cartridge.gif
Also I came up with a somewhat lower tech solution for my own kernal
cartridge testing.
http://users.on.net/~clockmeister/other/Kernal-Cartridge/
Clocky
> Sam <siemap...@quicknet.nl> writes:
>
>> I was wondering if it is possible to replace the internal cartridge
>> of a C64 with a kernal rom in a cartridge.
>
> Ultimax mode whenever the CPU accesses $e000-$ffff to force it to read
> from an external EPROM.
>
> If you want to access the ram below the rom in this address space
> you'll need access to the HIRAM signal to know if the access is meant
> for the kernal or the ram below it. This signal is not available on
> the expansion port - your options are a wire into the computer, a
> really messy hack that modifies the EXROM/GAME lines for a fraction
> of a C64 clock cycle (not very stable, needs adjustment for every
> single machine and sometimes temperature) or a full CPU emulation at
> the expansion port to determine the current contents of $0001.
>
> -ik
If you're going to hack the C64 a simpler solution is the one I implemented
I think.
http://users.on.net/~clockmeister/other/Kernal-Cartridge/
Works for me anyway.
Sam
I already saw the schematic of Ruud.
Your inplement looks good but needs to "hack" the C64.
In my message I wrote "replace te internal cartridge..." Off course I
mean: replace the internal kernal..
Regards, SAM
Leif Bloomquist
news:uocq0n...@dragon.akana.de...
> Yes, it is. Just add an external address decoder that will switch to
> Ultimax mode whenever the CPU accesses $e000-$ffff to force it to read
> from an external EPROM.
You get JiffyDOS as your kernal when you use a RAMLink, which plugs into the
cartridge port. Is this how the RAMLink does it? At least this proves it
is possible.
> If you want to access the ram below the rom in this address space you'll
> need access to the HIRAM signal to know if the access is meant for the
> kernal or the ram below it. This signal is not available on the
Is this why the RAMLink needs the internal cable? I have very little
experience with a RAMLink, it's just the first thing that comes to mind when
someone talks about the idea of a kernal-on-a-cartridge (which I would also
really like to see).
Maurice did talk about a JiffyDOS-on-a-cartridge way back in 2006, so he
certainly thought it was possible.
http://forum.cmdrkey.com/viewtopic.php?f=2&t=363
-Leif
Groepaz
> "Ingo Korb" <use...@mail.snowcat.de> wrote in message
> news:uocq0n...@dragon.akana.de...
>
>> Yes, it is. Just add an external address decoder that will switch to
>> Ultimax mode whenever the CPU accesses $e000-$ffff to force it to read
>> from an external EPROM.
>
> You get JiffyDOS as your kernal when you use a RAMLink, which plugs into
> the
> cartridge port. Is this how the RAMLink does it? At least this proves it
> is possible.
>
>
>> If you want to access the ram below the rom in this address space you'll
>> need access to the HIRAM signal to know if the access is meant for the
>> kernal or the ram below it. This signal is not available on the
>
> Is this why the RAMLink needs the internal cable?
yes and yes :)
--
http://www.hitmen-console.org http://magicdisk.untergrund.net
http://www.pokefinder.org http://ftp.pokefinder.org
There is often a large gap between theory and practice... Furthermore, the
gap between theory and practice in practice is much larger than the gap
between theory and practice in theory.
<Jeff Case>
Quantum Leaper
> Leif Bloomquist wrote:
>
>> "Ingo Korb" <use...@mail.snowcat.de> wrote in message
>> news:uocq0n...@dragon.akana.de...
>>
>>> Yes, it is. Just add an external address decoder that will switch to
>>> Ultimax mode whenever the CPU accesses $e000-$ffff to force it to
>>> read from an external EPROM.
>>
>> You get JiffyDOS as your kernal when you use a RAMLink, which plugs
>> into the
>> cartridge port. Is this how the RAMLink does it? At least this
>> proves it is possible.
>>
>>
>>> If you want to access the ram below the rom in this address space
>>> you'll need access to the HIRAM signal to know if the access is
>>> meant for the kernal or the ram below it. This signal is not
>>> available on the
>>
>> Is this why the RAMLink needs the internal cable?
>
> yes and yes :)
>
connect up the cable inside the C64 or 128 to the RAMLink and it works just
fine.
Snogpitch
cartridge ports.
in article apadnc_bQaeYgwHX...@supernews.com, Leif Bloomquist
at sp...@127.0.0.620 wrote on 8/31/09 3:01 PM:
> "Ingo Korb" <use...@mail.snowcat.de> wrote in message
> news:uocq0n...@dragon.akana.de...
>
>
> You get JiffyDOS as your kernal when you use a RAMLink, which plugs into the
> cartridge port. Is this how the RAMLink does it? At least this proves it
> is possible.
>
>
> -Leif
>
>
--
Snogpitch
snog...@prodigy.net
ICQ: 4989342
Webpage: http://pages.prodigy.net/snogpitch/
Sam Gillett
"Quantum Leaper" <lea...@bigfoot.com> wrote ...
IIRC, the cable is to prevent timing issues from raising their ugly little
heads. On some individual computers it is necessary. On others it is not
necessary, but should be installed to be on the safe side. Or, at least I
seem to remember the CMD documentation that came with the RAMLink saying
something like that...
--
Best regards,
Sam Gillett
Change is inevitable,
except from vending machines!
Leif Bloomquist
news:h7hp4u$ttm$1...@news.albasani.net...
> The internal cable for the RAMLink is optional, half the time I don't
> connect up the cable inside the C64 or 128 to the RAMLink and it works
> just fine.
Yes, because if Groepaz is right, that cable is only needed to access the
RAM under $e000-$ffff, and not a lot of programs do that.
-Leif