Olivetti M24

Olivetti M24 Running Sokoban
Olivetti M24 Running Sokoban

The Olivetti M24, sold in the USA as the AT&T PC 6300, was Olivetti’s first IBM PC-compatible and was a major success for the company. It followed the M20 which was based on the Zilog Z8000 and was unsuccessful because of a lack of compatible software. I used one of these back in the mid 1980’s.

I have two of these machines and have been able to assemble a nicely working machine using parts from both.

Repair Reference Information

The technical manual is the Theory of Operation manual on Bit Savers.

Power Supply

The schematic for the PSU is in the Theory of Operation manual, but the part numbers don’t match up to the markings on the boards, so someone on VCF has produced a marked up version which I have copied here for those who don’t have an account on VCF.

Marked up schematic of the Olivetti M24 PSU

Note that there are a couple of errors:

  1. R88 is 180R, not 220R
  2. C21 is 10,000uF, not 1,000uF