Commodore 64 Assy 250407 Rev. B motherboard and case

Assy 250407 Rev. B

This is a Version A-CR PCB produced from 1983 (known revisions include Rev. A, Rev. B & Rev. C). From this version and forward, the Commodore 64 board had an 8-pin video jack.

The inside of the machine:

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All voltage regulators and electrolytic capacitors have been exchanged for new ones as described in the C64 Capacitor Mod.

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The VIC-II and the PLA chips all have heatsinks attached to keep them running cool. Heatsinks and thermal tape have been bought from the Retroleum.co.uk spares shop.

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The machine was originally used at a Danish High School, so the character set has been changed to Danish by swapping the Kernal and Character ROM’s. I’ve had a few of these machines and it seems like the chips and adapters were manufactured by a professional company back in the days.

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The special Danish characters look like this:

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Capacitor C38 (51 pF) has been replaced by a 4.7 nF one to make the RESTORE key work like all the other keys as described in the C64 RESTORE Key Mod.

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The outside of the machine:

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As evident from the labels on the keyboard, the machine has a Danish keyboard layout. Instead of swapping the keys, small labels were added to indicate the new characters.

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The machine had previously been used at a Danish High School and tagged with the school’s initials and the machine’s number on the side (‘BG/54’). The case is in pretty good shape and the number on the side just adds to the authenticity of the machine.

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The power LED color is red.

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2 comments on “Assy 250407 Rev. B

  1. Excellent oldschool computer. We had BBC micro computers at our schools in England in the 80’s. If we had been given C64’s , we would have been gaming all day in lessons 🙂

  2. Thanks Neal! I think we had machines from IBM with green text. If we have had C64’s I guess people would have been more interested in the programming stuff…

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