"This disk is not readable by this computer. Would you like to initialize it?"

Hi,

First of all, is the Wallstreet's Mac OS 9 system working OK?

Generally speaking, attempting to transfer files to an old Macintosh computer using a CD-RW can be difficult. It is better to use a CD-R disc. Burn at a low speed. If burning a CD-R on a PC, a standard ISO9660 format can normally be used (the same should be applicable with a modern Mac). All Mac files intended for use on an old Macintosh computer must be kept encoded (MacBinary .bin or BinHex .hqx). Do not alter downloaded files in any way (that is, do not decode/decompress) until on the old Macintosh machine. Once on the old computer, decode and decompress using a suitable utility (such as StuffIt Expander).

However, a bootable CD needs an appropriate Mac file system, and would require special burning software. Do not expect this to work. Instead, look for original (genuine) Apple system CDs compatible with the computer in question.

If necessary, a PC Card slot of this PowerBook G3 series computer can be useful. A CompactFlash PC Card adapter with a CF memory card can often be used as a removable "hard disk". May even be bootable if formatted Mac OS Extended = HFS+.

Which disk to boot from can be chosen via the Startup Disk control panel.

http://manuals.info.apple.com/Apple_Support_Area/Manuals/powerbooks/0340667AMPWRBKUM.PDF

https://everymac.com/systems/apple/powerbook_g3/specs/powerbook_g3_250.html

I'm not sure what the built in Burn utility uses. It may be a combination disk, such as you can do with Toast. There, when I'm burning a CD or DVD as a data disk, I have this choice:

Okay, Mac & PC. I know that allows both Windows and the Mac OS to each see the CD or DVD as a native disk. But, what is that? FAT32 and HFS+? Even the manual for Toast doesn't tell you. I'd have to burn something just to find out.

I'll try both Burn and Toast with rewritable DVD and see what the OS says the disk format is.

If you use IOS9660, your CD will lose all resource fork data. Which means all OS 9 sound files and Type 1 PostScript fonts will end up as zero byte files. For best compatibility, burn the disks as Mac OS Extended (HFS+). That is still readable on even the latest Macs. The ability to read the original HFS format was dropped after Mojave.

Per Jan's note, the only way (or at least, legal way) to get a bootable Puma disk is to purchase a genuine, retail copy. DO NOT buy any gray disks you will see on places like eBay. Gray system disks are meant only for the Mac they shipped with.

Once you have a Puma install disk, put the disk in the drive. Restart and immediately hold down the C key.

Edit: And losing the resource fork data doesn't just destroy some files entirely. Without that data, your Mac won't recognize most of your files. They'll show up as blank, generic files unattached to any app.

Interesting. I'm not even sure where you found that drop down menu. I don't get that when I right click on a Burn folder.

But anywho! Both Burn and Toast Titanium burn the Mac data as Mac OS Extended (HFS+). Both can also create Blu-ray data disks - if you, of course, have a Blu-ray burner drive.

Toast is available in various places. Directly from Roxio is one option, and is the cheapest price I could find. If you plan on burning Blu-ray movie disks, then you would also need the $10 Blu-ray plugin for Toast.

Or, you could spend an extra $10 on Toast Titanium Pro, which includes the Blu-ray plugin, and lots of templates for disk creation.

Then the question becomes, is either worth it? If all you need to burn are data disks, then the built-in Burn utility is all you need. Why spend the money on Toast if you aren't planning on making any DVD or Blu-ray movie disks?

If the PowerBook is running OS 9, it should be able to read HFS+. I couldn't tell you what's going on for certain, but it could be the drive itself. Such as a dirty lens, or the laser is just plain dead.

Can it read other, older disks and is only failing on those coming from the Mac running Catalina?

...and it would probably be correct to assume that the disc is a CD-R (not -RW).

As a comparative test, if you have access to a Linux or Windows computer, you could perhaps burn a CD-R there, with a few Macintosh application files (downloaded from the Internet; encoded MacBinary .bin or BinHex .hqx). As Kurt Lang mentioned, the resource forks will normally be destroyed. However, a MacBinary or BinHex encoding will protect such originally encoded application files (including the resource forks), provided that nothing has been decoded/decompressed/opened until under Mac OS 9 on the receiving computer.

You may already have a CompactFlash PC Card adapter (for example, from SanDisk). Something like a 1 to 4 GB CompactFlash card could be used in its original PC (FAT) format for plain transfers of encoded .bin or .hqx files from a PC or modern Mac. A PC-formatted CF card will be recognised by Mac OS 9. Once on the Mac OS 9 Mac, one would not double-click on the received .bin or .hqx files. Instead, drag the files onto the StuffIt Expander program icon there, or open them from within the StuffIt Expander utility.

If a CF card is reformatted by the PowerBook G3 series Mac to HFS+ (Mac OS Extended), you could try to drag-copy a Mac OS 9 system folder to the card as a backup. With the correct Startup Disk control panel setting, the PB G3 Series computer may boot from this CF card.

Sorry, if you need Mac OS X, I can only recommend using appropriate, genuine Apple system discs (probably Mac OS X 10.2 Jaguar).

Otherwise, Mac OS 9 is a good system for this computer.