JohnElliott
Veteran Member
The Philips :YES was supposed to have DOS Plus (the predecessor to DRDOS) in ROM. I've never seen a ROM dump of it, though, so I don't know how it was implemented.
The Philips :YES was supposed to have DOS Plus (the predecessor to DRDOS) in ROM. I've never seen a ROM dump of it, though, so I don't know how it was implemented.
I worked extensively with Caldera & Novell back in 1996/97 to get the sources released. The "kernel" sources and command.com were released, but they put the brakes on the project shortly after that. I've still got the full source code distribution around here somewhere. Includes all the original compilers & assemblers needed. One batch file kicks off the whole build. The last time I ran a build (nearly 20 years) it took 45 minutes to compile everything.
g.
DR DOS's documentation includes a section on how to place the software into ROM. Whether it answers all the questions I can't say since I have not done it.
http://www.drdos.net/documentation/romhtml/romch1.htm and the two successive sections.
A ROM programmer to place the .BIN files into the ROM chips and also a modified BIOS ROM to look for the OS in ROM. I think Phoenix used to provide a set of suggestions on how to adjust the BIOS to include a ROM DOS as an option. I can't quickly find an online reference to it though. HP had a fairly detailed article on customizing DOS in ROM back in their Technical Journal during the 80s. Datalight has a FAQ which explains some elements of their implementation (ROMDOS) but full details require buying the $10,000 SDK.
I seem to recall from what Lightspeed info I could gather, that much of the effort was dedicated toward treating a ROM as a disk device.
All of this is past being important today, as flash devices are very common. Many thin clients, for example, use flash DOMs that plug directly into an hard disk (e.g. ATA) interface.