Recent content by joevt

An s-video cable will work for the keyboard.

Could be bad RAM? The memory test doesn't happen if NVRAM is invalid, then next boot the NVRAM is valid so it tries a memory test? Do you hear a boot chime? Command-Option-P-R to zap the PRAM? Keep the keys held down until you hear the boot chime a couple times? This thread talks about the...

If you find a graphics card that it doesn't work with, then we can make a fix for it.

I extracted the code. To load the code: On a Mac with a serial port: - Type dl command to begin download. - Paste the contents of the .4th file. - Press Control-D to end the download. It executes the contents which in this case just adds words to the Open Firmware dictionary. The dl command is...

I think Forth is easier to read than machine code or assembly. My script converts fcode to Forth such that the reverse process should produce the same fcode (or slightly better fcode since my tokenizer uses single byte fcodes for the constants -1,0,1,2,3 instead of 5 byte literals). Apple has...

There is a method to get the address for the SCC registers: Low memory global variables SccRd and SccWr at address 0x1D8 and 0x1DC respectively. But you still need to open the serial port driver to make sure no one else will mess with the SCC port that you want to use. You can check the ADB...

Which ROM is ProMedia 20? If you want to make changes to the ROMs, then you'll want to look at the Forth code. You can retokenize changes into a new ROM with my OpenBIOSStuff. I have a Open Firmware Extender 2.4 for Beige G3's that have Open Firmware 2.4. Open Firmware Extender loads Open...

My reply at https://68kmla.org/bb/threads/looking-for-formac-promedia-40-rom-rip.52158/post-588568

Macintosh Garden has CDs from Formac containing many ROMs or drivers. Just search for Formac. I think this one from February 2002 has 64 ROMs for 17 different products: https://macintoshgarden.org/apps/formac-drivers-version-2011-01-05-archive https://macintoshgarden.org/apps/formac-022001...

Is this transceiver just used to send the external clock to the two sides? Does the PAL do anything else? Isn't the external clock used on both sides of the connection? The external clock affects the data speed. Why use data speed to affect the data speed? If the same external clock is not...

It can do fill operations - solid color or patterns. A pattern is a source bit map that is used repeatedly. A solid color is like a pattern that is one pixel in size.

The 8500/8600 can sense when a composite or s-video display is connected. The DingusPPC emulator does emulate this behaviour. The bits are in a board register accessed at address F301E000. It's a 16-bit little-endian register. Read the register in Open Firmware like this: F301E000 rw@ 4 u.r...

There's a version of the GeForce 4MX firmware for AGP/PCI at http://themacelite.wikidot.com/wikidownloads2 The problem is that the firmware has dependencies on New World Open Firmware. Modifications are required to make it work on Old World Open Firmware as discussed for newer Nvidia cards like...

3.5" floppy drives have two heads so you can use both sides of a double-sided disk (the difference between a 400K and a 800K disk). 5.25" floppy drives only need one head because you can manually flip the disk over to use the other side. https://en.wikipedia.org/wiki/List_of_floppy_disk_formats

My fork of the DingusPPC emulator has a function MonitorSenseLines in applesense.cpp that can calculate and draw all the Apple Sense Code possibilities (anything possible with just diodes or wires).