Recent content by mrw

I'm so sorry. Thank you for trying!

The Mac Plus SCSI implementation is weird. In particular, it doesn't support blind transfers, where the CPU delegates data transfer to the SCSI chip: - Pages 393-394, Guide to the Macintosh Family Hardware, 2nd Edition Macintosh disk images begin with a SCSI driver the ROM reads on start up...

Add #include <stdlib.h> to bring in the correct prototype for malloc. Without that, the compiler assumes the return type is 2 bytes wide as show in the disassembly (Source -> Disassemble): Note the MOVEA.W D0,A0 instruction which moves a word (16 bits/2 bytes) from D0, malloc's result...

I removed the main board and didn't see any obvious issues. Given @Arbee's suggestion, I paid special attention to the degaussing circuit given (see attached schematics.) I don't know much about electronics, but I learned that in 1993, degaussing circuits often consisted of an RC circuit where...

Thank you @Arbee ! I've tested with two machines (PowerBook 180 and a Mac II), and each of those with the M1212 and a Dell UltraSharp 2001FP. Both machines with the M1212 show the same output as in the pictures. Since writing I used a degaussing wand on the M1212 and it still looks the same as...

Some additional pictures of plain colors might be clearer than the original grid: This should be red but it's green (there's an aberration at the bottom because I didn't do a long exposure for this one): This should be green but it's blue: And this should be blue but it's green: I've also...

I recently purchased an M1212 Apple Color Display that was shipped locally. The seller's picture confirmed its colors were accurate, but it was bumped badly enoug in transit that the colors now are off. I wrote a Think Pascal 4 program (attached) that demonstrates this by drawing labeled...

Until Macintosh Pascal, I hadn't either! Good point! It seems possible Apple used this mechanism to protect files internally, and makes it seem less coincidental that Macintosh Pascal uses it given that it was officially an Apple product. Maybe I should ask an Apple developer who was around...

Have you ever tried to copy a folder or file only to be stopped by a dialog that looks like one of these on System 6? (Alert that says: "That contains items that cannot be duplicated or copied.") (Alert that says: "That cannot be duplicated or copied.") ..or these on System 7? (Alert that...

Here's one I wrote in Lua, so you'll need a Wireshark built with Lua, and a recent version to get at the "llap" dissector via Lua. I've tested it with 4.2.2 on Debian Linux. Put this in the Wireshark plugins folder as a file named something clever like "ltoudp.lua". It's not perfect; the DDP...

@cheesestraws through-hole AirTalk would be neat, if you don't mind putting it on an ever-growing todo list! @bigmessowires I'm really sorry that I'm far away enough from the Bay that I can't join you all, but: is PowerBook battery rehabilitation too ambitious? There's been some good discussion...

I strongly recommend downloading a MacTech archive image, like the one below, which includes example source code and at least low-res pictures in articles that have them: https://macintoshgarden.org/apps/mactech-vol-1-17 For Apple's develop magazine, which that image includes, a better resource...

I recently used the PCB that started this thread (https://github.com/GeorgeRudolf/OldMacATX) to replace the power supply in my Quadra 650. Attached is a CSV of what I ordered from DigiKey for my build. Note that the listed parts and their quantities reflect that I received 5 PCBs that I opted...

Thanks so much for sharing this! I've ordered 5 boards from JLCPCB and the requisite parts from DigiKey. If I can get one to work with my Quadra 650, I'll use two more for my IIcis. I'll post my experience here when I've got a build done!

I recapped my PowerBook 160 with Mac84's parts list. The screen works much better than before the, but the top half is much darker and has much more ghosting than the bottom: This thread seems to describe a worse but similar situation...