CBM 8296

Released 1983: Commodore had allready from 1982 updated the CBM/PET series of small-business computers with a new series of computers. The new computers were called the CBM-II series (B series). These were not as successful and were abandoned in 1984.

Due to demand, the original CBM/PET machines were revived and fitted into the CBM-II case design. These were known as the SK’s (separated keyboard). The keyboard is detachable and they also had a monitor with a swivel feature. Initially, CBM 8032 and CBM 8096 (64KB extension memory board) were retrofitted into these cases.

Later the SK models got a new redesigned mainboard that already included the 64 kB or 96KB banked extension memory directly on the board. These were the CBM 8096 (32KB + 64KB memory) and CBM 8296 (32KB + 96KB memory).

The ultimate model was the CBM 8296-D with a built-in 8250LP (low profile) quad-density dual disk drive with a whole 1 MByte on each 5.25″ floppy. This model was only for the European market.

My CBM 8296

I bought mine locally here in Norway, it was a local pickup.

• Cleaning and scrubbing
  As usual I started with throughout cleaning, outside and inside, main unit and keyboard.

• Keyboard
  One of the keycaps had an internal part broken, the plunge. This seemed attempted disguised as it was loosely glued on, but the glue had not hardened, also the coil spring was missing. I took the keyboard completely apart, except for the broken plunge, this keyboard has no sign of wear and tear. I removed the broken piece of the plunge that was left, using a pick, also a small drill can probably be used for this. Next step was to 3D print a new plunge, this worked. But I found that I had a Commodore 64G machine that uses the same plunges, so I ended up using the 3D printed part in the C64G instead, and use the plunge from the C64 in the CBM 8296 keyboard, to keep this machine as original as possible. There are many of these machines to be found with the keyboard missing. As its loose, it seems to often has been lost over the years of storage and moving around. The spring coil is also the same as used in C64, so I got a spare one to use.The keyboard now feels and works as new, probably this machine has seen little use during its lifetime. 

• Monitor adjustment
  The display was a little bit tilted and also the position and size was a little bit off. I’ve corrected the tiltet display by loosening the CRT yoke and rotating it very carefully using a wooden stick and only one hand due to the high voltage present. Then tightened the screws when I was happy with the result.  The vertical position was next, adjusted by loosening and rotating  the adjustment rings on the crt tube, using a wooden stick and a mirror to see the display when adjusting inside the monitor. Only one hand and using a wooden stick as a precaution for beeing electrocuted. The rest of thw geometry asjustment can be done by adjustment screws.

• Replace capacitors
  I’ve replaced the old electrolytic capacitors with new ones.