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(Chiclet) PET 2001 - how to replace the 6540 ROM with 2716-2732 EPROM (explained)

giobbi

Veteran Member
Joined
Dec 23, 2012
Messages
951
Location
São Paulo country, Brazil
Hi all,
I have a chiclet 2001 with a fully working romset - except for the char ROM. I order to prevent the old chips as far as possible I planned to replace them with EPROM, as I did for the RAM set.
No need for a new idea: on the D'Asaro's web page you can find his clever and sleek solution, very compact. The only con is that it's a little tricky and it was released for PCBexpress, that doesn't allow to export the Gerber files.

(D'Asaro web page: http://www.dasarodesigns.com/product/6540-rom-adapter/ )

Since D'Asaro released it as an open project, I saw no problems to make an easier version and release the gerber for anybody who need it.

After built my own PCBs and test them, I released the gerber files on PCBway shared projects. Use PCBway if you like it, or get the Gerber zip file there and use any other service,like jlcpcb.com or whatever. I also attached the Gerber files here.

Here's the link to PCBway: https://www.pcbway.com/project/shar...540_ROMs_PET_2001_early_version_ee077568.html
It's still in revision while I'm writing, so it could take some time to be available.

IMG_20220616_173008--.jpg
the adapters installed and the original chipset on the way for the antistaticbag

IMG_20220616_172951.jpg
it works as character ROM replacement too

IMG_20220616_173034.jpg
the prototype. The final version is a little bit narrow to perfectly and has a better silk text
 

Attachments

  • 6540-2716 adapter - Gerber.zip
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Hugo Holden

Veteran Member
Joined
Dec 23, 2015
Messages
2,593
Location
Australia
Looks good.

The thing I like about the D'Asaro adapters is that he used thin pins on the adapter so that it does not damage the IC sockets. Most IC pins, across their flat faces are only about 0.28 to 0.3mm thick. Whereas many IC common adapter pins are closer to 0.5mm and some thicker. Also some of the Commodore IC sockets were not wonderful being "single wipe" types and they are really easily de-tensioned by putting a thicker pin in them, then later they will not connect to a standard IC properly and they are stuck with the adapter.
 
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