Where does NewtonOS keep its fonts?

[Screwtapello]

I apologise for this off-topic question. I have a hobbyist interest in the history of GUIs and of fonts in particular. The Newton in particular has some exquisite system fonts - Espy Sans in particular is a marvel of legibility at low resolution, and I'd love to be able to use it on more modern systems.

A little research suggests the NewtonOS is stored in ROM. I made a copy of the MessagePad 110 ROM, ran strings on it, and grepped for Sfnt, producing the following list:

oHpespyPlainSfnt
uespyBoldSfnt
rnnewYorkPlainSfnt
genevaPlainSfnt
helveticaWidthsSfnt
helveticaBoldWidthsSfnt
`QhelveticaItalicWidthsSfnt
*helveticaBoldItalicWidthsSfnt
timesWidthsSfnt
timesBoldWidthsSfnt
timesItalicWidthsSfnt
otimesBoldItalicWidthsSfnt

I see Espy Plain, Espy Bold, New York, and Geneva, which all seem very likely and reasonable. I also see a bunch of "Widths" fonts which would seem to be the "metrics-only" fonts used for printing to PostScript printers, so the OS can figure out how to lay out text without including all the font data.

However, Wikipedia tells me that "The Newton used the font Apple Casual to display text entered using the Rosetta handwriting recognition engine" which seems like a pretty important font I'd expect to see in the base OS. I guess it must be stored somewhere else, then, or in a different format, or compressed or something.

How does it actually work?

[MatthiasWM]

The Espy font family is here: https://www.macintoshrepository.org/26348-espy-complete-font-family
This link https://lowendmac.com/2000/using-the-espy-font/ has a list at the bottom of similar fonts, some without the Apple copyright.
This https://en.wikipedia.org/wiki/Typography_of_Apple_Inc. is a good starting link to learn about all Apple fonts.
One source of Apple Casual (called "Handwriting" on the Newton) is here: https://www.cdnfonts.com/apple-casual.font

If you are looking for the actual binary data of the bitmap fonts in rom, look for the sequence 'sfnt'. In the 2.1 ROM, one of this is at 0x004142C8, for example. The sfnt is based on the Classic Mac System 7 resource format. It's explained in detail here: https://www.newted.org/download/manuals/NewtonFontSpecifications.pdf

[splorp]

Newton fonts are actually OpenType format, but without any outline (vector) data. They only exist as bitmaps, hence the SFNT resource designation.