Re: commdore plus 4 cartridges

Hi Didier, the ROM's will be 23128's (16k x 8bit) They are pin compatible
with 27128 eproms and you can desolder the ROMS and replace them with
28pin sockets for prototyping. Looking at picture 92, the ROM on the left
is mapped to $8000-$BFFF and the one on the right to $C000-DFFF.

At reset, the 264 kernal probes for the bytes $01,$43,$42,$4d at $8006 and
if found, jumps to $8000 to start the cartridge.
I have developed  a couple of +4 cartridges, such as diag264
http://inchocks.co.uk/commodore/Diag264/HTMLManual/Diag264.htm so feel
free to give me a shout.

One thing you can not easily do on the +4 is cold boot into a cartridge
mapped to the kernal address space, it always goes through the onboard
kernal first.

Rob


> Hi,
>
>
>
> I've just received the plus 4 cartridge I bought on ebay.
>
> Inside there are 2 roms. (logo)
>
>
>
> I'm very busy right now, but in June, I'll try to draw some schematics
>
> And make the file to produce a pcb (lol never used eagle..)
>
>
>
> If it works I'll try to produce a few cartridge pcb
>
>
>
> If you have any advices ?  I' thinking to use www.olimex.com to produce
> them.
>
>
>
> Images of the cartridge:
>
>
>
> http://www.netfilters.eu/plus4/IMAG0090.jpg
>
> http://www.netfilters.eu/plus4/IMAG0091.jpg
>
> http://www.netfilters.eu/plus4/IMAG0092.jpg
>
> http://www.netfilters.eu/plus4/IMAG0093.jpg
>
> http://www.netfilters.eu/plus4/IMAG0094.jpg
>
>
>
>
>
>
>
> any idea of use on the jumpers on:
> http://www.netfilters.eu/plus4/IMAG0092.jpg
>
>
>
> any idea of the size of the roms ?
>
>
>
> --
>
> Didier
>
>
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>
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>
>
>


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