Recent content by joevt

You have the Open Firmware code (assembly and Forth) from my dump. You can look at the code to see what's happening. I don't know when real-base and load-base are setup/used - is it before Open Firmware has started (in System 7), or in the Open Firmware init code (Part1.txt) or in Open Firmware...

Silicon Beach Software was acquired by Aldus Corporation in 1990. SuperPaint became Aldus SuperPaint which is the version I'm familiar with. Adobe took over Aldus in 1994. https://en.wikipedia.org/wiki/SuperPaint_(Macintosh)

Appears to be C strings followed by variable type and bit number or offset (01=boolean, with bit number, 02=number with offset to value, 03=string with offset to string) So `real-base` is at offset 0x10 in the nvrm resource. It seems to have a value of FFFFFFFF = -1 in the Mac OS Loader...

I searched my Copland disk image for occurrences of a snippet from the nvramrc and found 7 occurrences. I mounted the disk image and searched only the HFS partition which also has 7 occurrences which means all occurrences are in the HFS partition. I take the offsets and divide them by 512 to get...

I did mention that in #7 You can set output to ttyb:57600 to increase the baud rate. A small patch is required to enable 115200 or 230400 bps. I made the commit in my DingusPPC fork. It makes it easy to get into Open Firmware on a pm6100 and it allows editing/saving the nvram...

A ghost window is visible in the last image of #1 It appears to be a ghost of the "Work" window from the image before that.

You can but there's also a checksum to update. It's a simple algorithm so you could just make a perl or python or bash script. You can look at the DingusPPC source code for the format. Normal NVRAM has the Open Firmware variables at offset 0x1800 but the Copland NVRAM has Open Firmware variables...

I didn't touch System Picker. I used System 7.5. Not 7.5.5. I don't know if that matters. Capslock snag key might work if you press it as soon as you see the happy Mac. Or maybe before that when you see the gray screen.

I can at least get into Open Firmware with DingusPPC emulating 136 MB of RAM. I probably won't be able to get to a sad Mac until SCSI emulation is working properly with the Open Firmware SCSI driver. Copland may require a second Mac connected to the modem port for debugging (but they do say it...

All those numbers had to mean something :)

I wish I had bothered to look at the Figure 5.2 that Figure 8.5 was pointing to when I was looking at Figure 8.5 the first time.

I believe it's an actual Apple Open Firmware implementation that uses some info from System 7.5 (search for >hwinit). I don't know how it compares to the stub you mention. It's more than just a device tree. It has Open Firmware packages and drivers. It has version 2.0 so it's newer than the...

Apple did make a Open Firmware for NuBus Power Macs. It's part of the Copland boot process. It is loaded by System 7.5 and uses some info from System 7.5 (video framebuffer information, Open Firmware section of nvram from a binary file, etc.). It is being discussed on the DingusPPC discord. I...

Congrats on solving the problem! The LS166 did appear to be shifting bits correctly - all characters being displayed had all bits matching the bits of a character from the Video ROM (Figure 8.8 #5 ) which means bytes from the Video ROM were being received by the LS166 correctly. The...

Open Firmware does contain code for MFM drives. Open Firmware, 2.0.2 for PM 4400 and 7220 can choose between a MFMfloppy device and a swim3 device depending on some value read from a board register at offset 1a000 of OHare. There's a Open Firmware driver for swim3 but not MFMfloppy. In Open...