New blog post! If you're setting up a BlueSCSI image for your classic Mac, there's lots of little tricks and traps for the first-timer. I'm hoping this entry will make things easier, and you'll also learn how to change your hard drive icon... in Japanese. #retrocomputing#mac68k#bluescsi
Welcome home! Let's get you a nice cozy heatsink and get you settled back in your case. Thanks to Amiga of Rochester for getting everything fixed up! #motorola#retrocomputing#68k#mac68k
Logic board and PSU recapped, 68LC040 replaced with the real deal, 16 meg memory upgrade, a nice new @BlueSCSI, and a new (hopefully) quieter fan. I'd love to get a full 1024k of VRAM but those SIMMs are hard to come by. #retrocomputing#mac68k
New #Insentricity post: Transforming Apple Internet Router into a Linux daemon.
It took until the middle of April, but with the help of several people I was able to put together a Docker container image that can be used as a sort of Apple Internet Router daemon. The config can be passed in entirely from outside the container and no pointy/clicky is required inside the emulated Macintosh.
I started on 8 bit micros and I have a lot of nostalgia for them. But, my favorite era of computing starts with the arrival of true 16 bit machines and ends with the arrival of USB. Amiga, 286-486 PCs and 68k Macs. The experience was sophisticated and useful but the machines were still focused on getting a job done and not on extracting money or personal data from the user. And they looked pretty. 😁
The classic MacOS code segment approach is kind of fascinating. I had just sort of assumed that, being a 32bit architecture, things would be much simpler, but I'm used to 32bit platforms that lean heavily on an MMU.
The desire for position independent code (and avoiding complex relocation) combined with the 68K's limit of 16bit offsets for PC-relative access, and the need to be very frugal with memory in early Mac systems clearly drove a lot of this design.
That was an adventure. Managed to get one of the included demos to build with Consulair Mac C 5.02 on System 6 (in the Mini vMac emulator).
Setting up working search paths with the Path Manager was a bit involved. The files on the install disks were not actually organized in a way compatible with the default search path setup.
And the resource compiler refused to write a .rsrc file, but would write a .rel, which did link with some changes to the link script.
For this exploration of Classic MacOS programming I wanted to aim for relatively early (more late 80s) to capture much of the feel of the early Mac platform, tooling, and APIs, but not too early because developing software on an 8MHz floppy-only platform with 512K-1024K ram is pretty rough (more pain than nostalgia).
I was thinking System 6 and an '020 or '030 machine, and found an LC III on ebay and pulled the trigger before realizing that meant System 7.1 minimum.
System 7.1 is at least still (the very end of) the pure 68K era, and I can use mid-late System 6 compatible tooling (like THINK C 5.0) and APIs, so it's not the end of the world.
And to my understanding it should be entirely possible to write software that'll run just fine on earlier hardware (provided it fits in the memory constraints, sticks to the compatible Toolbox calls, etc).
The CODE Editor for ResEdit is a neat little addon that lets you view full disassembly (instead of just a hex dump) of CODE resources, including symbol names, if present, etc.
The original Inside Macintosh books are really nice technical references for the 68K Mac Toolbox, etc. Luckily there are scanned versions available online, but sadly these lack tables of contents which makes them rough to navigate.
The pdfoutline tool can combine a PDF with a TOC to produce a new PDF, so I'm working my way through writing one up so I can have more convenient versions of these to flip through.
While delving into native 68k Mac development, I have discovered that I am now soft and weak and find it rough to read dense C code without at least some minimal syntax highlighting.
But as far as I can see, it simply DID NOT EXIST back in the 68k Mac era. BBEdit 4 supports it, but it's a post-System-7 post-PPC fat binary.
Anyone know of anything before that? Were there any notable competitors to BBEdit for programmer's editors on 68k Macs?
Exploring software development on Classic 68K MacOS (late System 6 / early System 7) is wild.
I got THINK C 5.0.2 running in emulation, building some of the sample projects... and was wondering where exactly the intermediate files are going because I don't see anything on disk anywhere...
Turns out the compiler just stuffs all that in the project file itself, because I dunno, why not!
Reading about the Resource Manager, I suspect the motivation here is that to use resources as a little cached database or filesystem -- they can be marked Purgeable so the Memory Manager will dump them when it needs space and it can be arranged that if they've been modified they'll be written to disk before being Purged. Especially in earlier and floppy-based MacOS, I assume being able to be lazy about writing data back to disk like this was a pretty big win.
The NuBus started as an MIT research project and was used in such diverse machines as the NuMachine by TI (originally designed by Western Digital), LMI's Lambda and TI's Explorer Lisp machines, the TI1500 family of Unix servers, Apple's 68k (starting with the Mac II) and first generation PowerPC Macintoshes (7100/8100) and, in a modified version, as expansion bus for the NeXT Cube.
Can't make up what this pin 5 is doing on this chip…
It's a supervisory circuit for old Macs that switch from battery to +5V to power the EGRET, but this pin goes to the video CLUT…
Vcc < .8V it's 0V
Vcc > 1.2V it's 1.2V
In-between it starts to oscillate… Could it be some watchdog thingy?
Tant que j'y suis j'ai branché mon lecteur de CD-ROM Apple que j'utilisais avec l'Atari Falcon (et par miracle j'ai trouvé le bon câble SCSI au fond de la boîte à bouts de PC).
Pas de soucis, ça fonctionne du premier coup. #retrocomputing#apple#macintosh#68k#Mac68k