[HN Gopher] Mac SE/30 logicboard recreation
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Mac SE/30 logicboard recreation
Author : zdw
Score : 131 points
Date : 2021-03-18 20:55 UTC (2 days ago)
(HTM) web link (68kmla.org)
(TXT) w3m dump (68kmla.org)
| imglorp wrote:
| Where does somebody get the ROMs for one of these?
| krallja wrote:
| Preserving or recreating the logic boards is important for
| historical recreation of antique machines -- as the originals get
| destroyed, there's less opportunity for new research. Having
| recreations like this lets more people play with these historical
| machines.
| sitkack wrote:
| Another cool part is that those old boards could get extended
| so that we can more easily sniff the buses or pause and
| visualize main memory, etc. So that we may better lift these
| artifacts into a purely symbolic space.
| superjan wrote:
| Nice project. Tip: for high quality CRT photos make shutter time
| is equal to a multiple of the refresh period. 1/60th, 1/30th,
| 1/20th and so on.
| wanderingjew wrote:
| The vsync of the se/30 is 59hz so good luck with that
| theatrus2 wrote:
| Stop down and take a long exposure. You just want to avoid
| the focal plane shutter or digital rolling shutter, and
| capture one beam paint, or lots of beam paints to even out
| the intensity.
| im_down_w_otp wrote:
| The person working on that project does incredible work. I have
| one of his upgrades that added a 40 Mhz 68040, 128k cache, and
| Ethernet to my old SE/30, and it's been fantastic. I run System
| 7.1 on it to play around with HyperCard, Word 5, Excel 4, and a
| couple other old programs.
|
| It's fun to make things in HyperCard as a great interactive and
| immediate feedback teaching tool for introducing my kids to
| programming. More than that though it's nice to sit down and draw
| inspiration from an era and implementation that went out of its
| way to take a handful of very well researched UI & UX metaphors
| and deploy them consistently and thoroughly. When I fire the
| thing up and poke around it feels like having the Software
| Engineer & Product Designer version of a serene Japanese garden.
| The transition from a little 9" B&W screen to my dual 27" LCD
| workstation is always jarring, and I always feel like the clarity
| of my thoughts and focus suffer immediately.
| dhess wrote:
| Does Bolle sell those upgrades? Got a URL?
| hakfoo wrote:
| What I'm hoping for, and this extends to all the reproduction-PCB
| projects (aside from the Mac ones, I've seen a replacement Atari
| 800XL and some Amiga designs) is that we can come up with a way
| to reproduce the ASICs rather than scavenging them from dead
| units.
|
| For some machines, there may be an ample supply to scavenge (old
| Macs being famous for barfing their batteries in a way that
| destroys the PCB but leaves the chips intact), but some other
| designs have far more limited supplies of spares. Plus there's
| the attrition risk-- something is gonna get damaged while parting
| out some percentage of the time.
|
| The introduction of replacement ASICs would allow us to grow the
| total population of a rare platform. I could imagine offering a
| turnkey kit-- a PCB plus every part necessary to populate it and
| have a working vintage Mac/Amiga/Atari/etc, with fresh capacitors
| and enthusiast quality sockets and PCB materials. They were able
| to offer such a kit for the IBM PC, but that was famous for not
| using custom components.
| monoideism wrote:
| Really, the best way to solve this is likely with FPGAs, not
| ASICs. If you're not using an original chip, does it really
| matter if it's an FPGA or not? Already, most of these
| reproduction PCB projects, including this one, end up using
| PLDs to replace hard-to-find specialied ICs (and even those
| PLDs are at risk of EOL). So it's not like they're using 100%
| original chips, anyway.
|
| I understand the urge, but unless the cost of ASIC
| manufacturing drops dramatically, I don't see this as being
| practical for small runs like hobby reproduction boards.
|
| Edit: I forgot to add: this is impressive work, nonetheless!
| hakfoo wrote:
| I suppose it depends on how you're using FPGAs. It seems like
| a lot of the FPGA products-- things like MISTer-- are system-
| level emulators, which rarely provide full legacy I/O
| breakout. You can emulate a complete 68k Mac on a FPGA, but
| where do you attach that weird NuBus card?
|
| Now, replacing individual chips with FPGAs/PLDs is likely to
| retain that, although I could imagine it's a lot less
| forgiving of an emulation, when it has to match the analog-
| domain properties of the original chip somewhat.
| monoideism wrote:
| > You can emulate a complete 68k Mac on a FPGA, but where
| do you attach that weird NuBus card?
|
| I just looked, and NuBus has 96 pins with clock rate of
| like 20 MHz. There are FPGAs with > 500 GPIO that can
| easily handle that clock rate, and ones with over >200 GPIO
| that are fairly affordable. Now, I mess around with FPGAs,
| but I'm not an electrical engineer, and there may be other
| issues. But it seems doable.
|
| Any electrical engineer and/or hardcore FPGA hacker want to
| chime in?
| zeckalpha wrote:
| Further in the article, there's a discussion of replacing
| custom PAL logic with modern Atmel chips.
| monoideism wrote:
| I mentioned that ("including this one"). Problem is,
| they're Atmel chips that are still in production, but I
| wouldn't call them "modern". Most competing PLDs are now
| out of production, and it wouldn't surprise me to see the
| atmel f16v8 series follow. More and more people just use
| cheap CPLDs or FPGAs (which unfortunately aren't available
| in DIP packages and so not pin compatible with the old
| custom ICs used in the 80s).
| tyingq wrote:
| If you read the comments on the story, the author did appear to
| have reverse engineered several of the Apple branded PAL chips
| on the board. So he was able to program new ATMEL PAL16R8Bs as
| replacements.
| gigel82 wrote:
| I appreciate this for academic purposes but in reality, unless
| you have a really unique / odd peripheral that only works with
| the antique machine's interfaces, it's much much easier to
| emulate in software.
| [deleted]
| williesleg wrote:
| Why the F would anyone do this? There's plenty of stuff already
| around.
| RodgerTheGreat wrote:
| Looks like decent progress being made on cooking up modern
| replacements for some of the custom chips, too. The prospect of
| being able to make fully-populated logic boards from off the
| shelf parts is exciting!
| pcdoodle wrote:
| Wow! Impressed that he was able to get away with 4 layers. I
| wonder why apple needed 6 layers? More grounding?
| Someone wrote:
| My 100% guess would be 30 years of improvements in automatic
| PCB layout software and CPU power to run it (it wouldn't
| surprise me if the original was partly/largely/fully laid out
| by hand, but that's a guess, too. It wouldn't surprise me
| because I know very little about this)
| repiret wrote:
| Auto layout is still pretty terrible and used sparingly.
|
| I would guess it's more 30 years improvement in CAD - it's
| easier to keep fiddling with the layout until you make it
| work than it used to be.
| phibz wrote:
| Maybe my dream of a Mac SE/40 can finally be realized, all one
| board. No add on accelerator.
| rezmason wrote:
| If this is ever for sale, I'm buying it.
| kkylin wrote:
| It makes me wish I had kept my SE/30.
| Bud wrote:
| Who needs a re-creation? I just pull my SE/30 off the shelf.
| Still boots! :)
| nsxwolf wrote:
| Very nice even with the SCSI mistake. Plenty of production
| systems shipped with more bodge wires than that.
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