Note: The 5499 On-Line note isn't really part of the brand note family. Whilst it's certainly a notebook, it's a weird dead end portable terminal which has very little use unconnected to a maintrame.
PS/55 note - The PS/55 was a range of Type-55xx computers for only Japan. They're based on the PS/2 but ISA bus and with special Japanese localisations supporting the more technically difficult languge to display on screen and type on a keyboard.
The 'note' branding was devised for the Notebook versions and within Japan all had to be in the 5523 model range (as opposed to 5535 for laptops). The original (or 1st Generation) 12Mhz PS/55 Note was the 386 5523-S0x model with sandwiched planars and room for either a FDD or HDD.
PS/55 Note N23 SX - The slightly later (2nd Generation) 16Mhz 386 PS/55 Note N23 SX had a single motherboard and room for both FDD and HDD. Also ISA bus.
PS/2 Note N33 SX - The Japanese first two releases of the Japanese PS/55 notes were so successful, they evolved into the international release of the PS/2 Note N33 SX which recieved a change in Type to 8533 and was a a model range consisting of both the 1st and 2nd Generation PS/55 Notes, but both of them released with no internal floppy drive and a Western keyboard. Obviously these are ISA bus.
At this point there are deviations from the bloodline of the N23 and N33 which where other Japanese PS/55 notes which includes the T22sx (1992), N27sx (02/1992) (Japanese-only release similar to the PS/2 CL57SX model), C23V (10/1992) along with the PS/Note series included models like the PS/note 182 (A PS/1, 386SL-based machine) and then the PS/Note 425 and 425C (486-based), which were essentially the same as the ThinkPad 350/350C.
PS/55 note C23V - we've speculated this 5523 model took the N23's model name and adopted the C(olour) or M(onochrome) letter replacing the N(ote). This is a curious beast, because it's a real bridge between the Notes and the 700C because it has that TFT colour screen which has now been miniturised into a notebook lid. Still no trackpad, and it has the look and feel of a note with the curved base. I haven't seen the inside but I suspect it's completely different to the previous notes because the RAM slot is now above the keyboard, not underneath.
PS/2 Note N51 SX & SLC- following from the international success of the N33 SX, the machine evolved into the N51 which eventually would become the N52 Thinkpad 700C but with the N replaced with C for Colour and M for Mono. The bus switched from ISA to MCA in line with IBM's 95xx series of machines including the 700 and 720.
Other notes which were individual offshoots were:
PS/2 Note N45 SX and SL were <possibly> manufacturered by a Zenith and it shows. They're closely related to Zenith machines, much like the 300 was.
N27 SX was the first iteration of the colour laptop which was released as the CL57 in the west, but most likely produced in Fujisawa. Due to it's size, it really shouldn't have the N model name, as there is no way it resembles a notebook.
T22 SX was a strange combination a notebook sized tablet with a detachable keyboard.
PS/note Type 2141-182 was equipped with 80386SL CPU and the PS/note 2141-N82 was equipped with 80386SX and released in 1992. This line has a 7-row keyboard layout. The case badge uniquely resembled the style of the PS/1. Interestingly the PS/1 Model range had 2141-182, 2141-E82, 2141-S82, 2141-M82, 2141-N82 and 2141-W82 types. and this is the only IBM notebook with that PS/1 type number. In addition the notebook shares striking similarities with the Lexmark Lexbook AR-10 and has the same keyboard. At the time, it's possible the PS/1 Team were in the same building as Lexmark people, and perhaps this was a collaboration. This machine was succeeded by the 2618 425.
Model 425/425C are identical to the the Thinkpad 350/350C.
