Recent content by joevt

Read the feature control bits with this: F3000038 rl@-flip 8 u.r which works without opening the PC floppy device in Open Firmware.

The rev D ROM does have support. Check the Heathrow feature control bits (32-bit register at offset 0x38 of the mac-io device). /** O'Hare/Heathrow specific registers. */ enum { MIO_OHARE_ID = 0x34, // IDs register (MIO_HEAT_ID) MIO_OHARE_FEAT_CTRL = 0x38, // feature control...

I think it does all the things the Z8530 SCC can. Same register set for all 68K and PowerPC Macs which include an SCC. https://68kmla.org/bb/threads/localtalk-but-faster.45615/post-505309 I'm not sure what you mean by RS422 signals. RS422 has differential pairs while RS232 has a single line...

LC III's gestalt ID is 27? aka gestaltVail? The flasher has these 5 options for that gestalt ID: - Intel 28F020, write: 40400000 read: 40800000, 2 banks, 1 MiB each, not PDS (040, also works on Quadra) - AMD 28F020, write: 40400000, read: 40800000, 2 banks, 1 MiB each, not PDS (040, also works...

Since you have a ROM slot, it is possible for a ROM module to exist. I don't have a list of everything Apple made so I can't say if Apple did or didn't make a ROM module.

Asking me to prove a negative?

level shifter?

Wouldn't the G3 DIMMs be wired similar to PowerSurge DIMMs (except the voltage source)? Schematics at: https://bitsavers.org/pdf/apple/powerpc/PowerSurge/ROM_Flasher/ G3 and PowerSurge/TNT/8600 schematics are at: https://www.macdat.net/repair/apple_schematics.html Both G3 and PowerSurge...

The Macintosh Portable schematics have a slot named ROM and labeled J10. It's 16 bits wide and has 23 address bits (excludes address bit 0 because it's 16 bits wide) similar to RAM slot J11. This is for the M5120 (non-backlit). I don't have schematics for M5126 (backlit) version...

That output appears to be good. Only complaint is your input command line was truncated at 80 columns width, but I think that's ok since everything else was not truncated. One improvement might be to do setenv fcode-debug? true and restart before doing the commands. But it appears that...

I would have to compare the Part1.txt and Part2.of files of 4.1.9f1 and 4.7.1f1 to find all the differences, which you probably don't care about, such as adding support for vectors , 16-bit fcode numbers, booting from sata, etc. It's just Open Firmware stuff that mostly has nothing to do with OS...

Newer Macs with modem port to serial port adapter can use AppleTalk (LocalTalk). For example, a B&W G3 with Griffin gPort or similar adapter. https://68kmla.org/bb/threads/introducing-and-interest-check-circuittalk-localtalk-for-powermac-g4.40182/ http://alexhixon.com/jamport/index.html

I have a 4.7.1f1 firmware updater that might work with your iMac. It's the latest 32-bit firmware updater that I have. It has config blocks for 66 different Mac models. Your iMac has prod-id:0x0081.00 which is renamed from "Kihei" to "P7". Versions of the firmware updater since 4.5.5d2 have...

This is an iMac so the GPU is probably the original. Grab the iMac firmware from Mac OS X and we can compare to make sure the firmware updater flashed it correctly. It's probably fine since it has checksums.

One way to tell if you did it right is to open the file that you created and compare its contents to what you saw when you did the command. In this case, it seems that only part of the output was saved. You need to increase the terminal scroll back buffer in your Linux app. In macOS, I use...