Even with the full 64MB of RAM, OS 9.1 is a burden to a 1400. NuBus Macs have to be tricked into installation of 9.2.x, an exercise that is scarcely worth undertaking but for the experience.
OS 8.6 is by far the most grateful and stable OS for the PB 1400, whether or no the Mac's CPU has been upgraded. The full complement of RAM is a Good Thing in any case. The 1400 is a fine machine, but prevented from some advances by its 10MHz NuBus architecture. I have a 1400/G3/400 (Sonnet) and two 1400/G3/233s (NewerTech). They hold their own for utility as PowerBooks, ie portable notebooks, with many a later PB model. However, they are definitely from before the era of expectation that they also be miniaturized desktops. The 1400/400 is still useful for dial-up web work away from home/on the road. It's the available browsers that begin to creak with Macs of that age, especially shown when snotty site owners tell you that you should upgrade your browser because they haven't the wit to understand who is the customer.
de
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(60x) 13DT + 3PB + PTPro; (G3) 7DT/MT; (G4) 3T + PB. System 8.1 to OS 10.5.8
OS 8.6 is by far the most grateful and stable OS for the PB 1400, whether or no the Mac's CPU has been upgraded. The full complement of RAM is a Good Thing in any case. The 1400 is a fine machine, but prevented from some advances by its 10MHz NuBus architecture. I have a 1400/G3/400 (Sonnet) and two 1400/G3/233s (NewerTech). They hold their own for utility as PowerBooks, ie portable notebooks, with many a later PB model. However, they are definitely from before the era of expectation that they also be miniaturized desktops. The 1400/400 is still useful for dial-up web work away from home/on the road. It's the available browsers that begin to creak with Macs of that age, especially shown when snotty site owners tell you that you should upgrade your browser because they haven't the wit to understand who is the customer.
de
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(60x) 13DT + 3PB + PTPro; (G3) 7DT/MT; (G4) 3T + PB. System 8.1 to OS 10.5.8