Osirix - Motorola 68000 Homebrew computer and OS

[iansjack]

I have a 73-year-old friend who solders surface-mount components by hand. I've no idea how he manages that, but clearly you are not trying hard enough.

[AMenard]

I have a 73-year-old friend who solders surface-mount components by hand. I've no idea how he manages that, but clearly you are not trying hard enough.

I'd need to take a couple of valium pills to steady my hands first.

But joking aside, those PCB ovens look and work real nice, I'm tempted to get myself one as a christmas gift this year. It would also simplify the hunt for components as smd are quite cheap and take less storage space.

[SpyderTL]

I had a batch of Amiga 2000 and 500+ with leaking battery that damaged the board beyond repair. I was able to save the 68000 from those and from an Atari 520STfm that was damaged during shipping from Greece (something fell on it and cracked both the case and the PCB). I also have two 65C02 from some defunct Apple IIe and two 6510 from a couple of burned out C64. I ordered a couple of Z80 (brand new!) since I've found a nice project for those while researching for my homebrew computer. I may also get a couple of Intel 808x just for the sake of completness

Here's an idea. How about mounting all of them on a single board. Maybe put 4 sockets of each CPU type on a single board. Then get some RAM and mount that on a separate board, and connect them together with either a ribbon cable, or just stack them with a common header.

Then, run everything else through a USB controller port. Video, audio, network, etc.

I'd love to be able to mix and match any CPU with any RAM, and plug in everything else to a hub.

That would be a fun project.

[Solar]

Note that the Amiga's architecture actually provided all the connectors necessary for plug-in CPU and RAM in an expansion slot. This allowed to add "turboboards" with much more powerful CPUs and RAM slots. Later on, those "turboboards" also included e.g. SCSI controllers, graphics card slots, and -- in the end -- even CPUs of a completely different family (PowerPC). While expandability might not be a top priority for a homebrew hardware project, I always thought this to be one of the nicest features of the Amiga brand. Even second-generation A2000's could be "brought up to speed" with the latest models just by adding an expansion card, without the need to get a whole new system, case, power supply, mainboard and all.

(The first-generation A1000 could theoretically expanded that way as well, but for various reasons -- including the comparatively low number of A1000's sold -- the aftermarket never took off.)

[iansjack]

Even the Amiga 1200 could be expanded in this way. Very useful for ray-tracing fans to be able to drop a 68030 in to their 1200.

To be fair, most computers had - or have - this capability. I can remember transputer cards for the PC (and - going the other way - Z80 ones). But, other than the Amigas, there was very little demand for such expansion cards.

But I still think the 68000 family was one of the most elegant designs.

[Solar]

My A1200 sported a card with a 68060 @ 50MHz, a PowerPC 603e @ 240 MHz, a SCSI controler, 256 MByte of PS/2 RAM, and a Permedia 2 graphics card. All on that one expansion board...

I once took this beauty to a friend for a round of gaming, when a man on the train pointed at the A1200 in my lap and said, "I once had one just like that."

I answered, "I seriously doubt that". (He meant the A500...)

Unfortunately I accidentally short-circuited the board in 1999, killing most of the components, which marked the end of my personal Amiga era.

[Candy]

Add a current-generation Vampire and go even further. I'm not active in the Amiga scene but there has just been a new AmigaOS release.. so something's brewing.

[eekee]

Did you get a PCB oven? If not, well, people use those little counter-top kitchen ovens. (This sort of thing.) I'm told they work well. My friend even prefers SMT with an oven to soldering through-hole components by hand.

Just don't use the same oven for your dinner.

[Sik]

I mean, 68000 cores for FPGAs are very common.

Something I noticed some days ago is that the Z380 is still being sold (basically a 32-bit Z80, and yes it's backwards compatible aside from invalid opcodes and stuff like timings, of course), and by that I mean "active" parts rather than obsolete or old stock. 68000 and Z80 was a very common pair, I wonder what you could get out of a 32-bit 680x0 and Z380 put together…

EDIT: if anybody is interested https://www.digikey.com/products/en?mpa ... 8FSG&v=269
Yeah, it's pricey at $22 an unit (under $16 at large quantities), but I doubt anybody will use one of these for anything at large scale