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croissantking's conquests
Posted by: croissantking on 2024-02-28 05:02:58 That is really special. I've never seen an 840 with ROM. That opens up some really interesting projects for you. Oh really? How nice to know. I figured it would be like the IIsi where early production models had the ROM on a SIMM: they aren’t super rare, just much less common.
Posted by: Phipli on 2024-02-28 05:13:43 Oh really? How nice to know. I figured it would be like the IIsi where early production models had the ROM on a SIMM: they aren’t super rare, just much less common. It's more than it opens the door for a load of projects. The 840av was planned for release with a bootable 7.1.2 in ROM, you could add this back in some day. You could also potentially do in computer ROM development with one of the new Quadra compatible ROMs. Checking the date code, it is an Aug 1992, so not a release day machine, but interesting. They're quite hard work - even recapping is fiddly. Take more care than usual. There is a lot of plastic near caps and hard to reach capacitors. If you find a source of replacement DSPs, let me know before you order, I could probably do with one too. My dad's is battery bombed and it attacked the DSP a little.
Posted by: croissantking on 2024-02-28 15:12:58 Having today learned the full name of our community, I will henceforth be referring to my conquests as liberations.
Posted by: demik on 2024-02-28 15:51:23 That is really special. I've never seen an 840 with ROM. That opens up some really interesting projects for you. Mine has a ROM slot as well. That's a feature of "early" boards. Also came without a ROM, so I flashed a 840av ROM into a GGLabs SE/30 ROM, put it in the slot and it booted 🙂 Si no need to build anything custom, 2MB flashable ROMs from Mac IIs will work.
Posted by: croissantking on 2024-02-28 16:12:25 It's more than it opens the door for a load of projects. The 840av was planned for release with a bootable 7.1.2 in ROM, you could add this back in some day. You could also potentially do in computer ROM development with one of the new Quadra compatible ROMs. Presumably one could gain this functionality by soldering a ROM socket onto a board that's missing one, if he or she also removed/disabled the onboard ROM chips? ROM development definitely isn't my forté - I wouldn't know where to begin. Tinkering, tweaking and restoring hardware is much more my thing. I'd be open to collaborate with others on such a project, for sure. They're quite hard work - even recapping is fiddly. Take more care than usual. There is a lot of plastic near caps and hard to reach capacitors. Yes, I see it's a different ball game to a II series Macintosh. Much finer traces and much more delicate ASICs. If you find a source of replacement DSPs, let me know before you order, I could probably do with one too. My dad's is battery bombed and it attacked the DSP a little. Of course - I'll keep this in mind.
Posted by: Phipli on 2024-02-28 16:20:19 Presumably one could gain this functionality by soldering a ROM socket onto a board that's missing one, if he or she also removed/disabled the onboard ROM chips? I think they're hard to find, but I could be wrong. I have one... And haven't decided what to fit it to. Of course - I'll keep this in mind. Thank you 🙂
Posted by: croissantking on 2024-02-28 16:23:37 I have one... And haven't decided what to fit it to. Your SE/30 Reloaded build? 😛
Posted by: Phipli on 2024-02-28 16:39:36 Your SE/30 Reloaded build? 😛 I don't have a reloaded, just a traditional one that has been in the family since the 90s. We're not very good at throwing things out.
Posted by: croissantking on 2024-02-29 03:24:40 Curious if it's going to be a real one or not. I can tell swapping a full 040 onto a CPU board from a 520/540 does indeed work just fine, the 550 ROMs are not needed for the FPU to do its thing. I'm 99% sure it is. It's an XC68040FE25M - I've seen a photo of it and it's still attached to a vintage PCB of some sort. I'll start a new thread about it when it arrives, in about two weeks.
Posted by: Bolle on 2024-02-29 03:28:57 I'm 99% sure it is. It's an XC68040FE25M - I've seen a photo of it and it's still attached to a vintage PCB of some sort. I'll start a new thread about it when it arrives, in about two weeks. Ha yeah, that sounds about how I got mine. Very unlikely for it to be not real in that case.
Posted by: mg.man on 2024-02-29 04:03:21 "ROM socket" -- I think they're hard to find Remind me... how many pins? 68?
Posted by: Phipli on 2024-02-29 04:25:41 Remind me... how many pins? 68? 64 I think, counting some photos on eBay.
Posted by: croissantking on 2024-02-29 04:31:42 64 I think, counting some photos on eBay. This is right
Posted by: mg.man on 2024-02-29 04:32:50 This is right So... like this? -- https://www.peconnectors.com/sockets-pga-cpu-and-memory/hws1788/
Posted by: croissantking on 2024-02-29 04:38:33 So... like this? -- https://www.peconnectors.com/sockets-pga-cpu-and-memory/hws1788/ Yes - I think quite a few people have bought from here. Not sure if there's a minimum order quantity, or what shipping to the UK would look like. I suspect you'd be better off buying in bulk.
Posted by: mg.man on 2024-02-29 04:42:45 Not sure if there's a minimum order quantity Yes, I believe there is. I'm ordering some stuff for another well known member - for delivery to my folks' in US and collection when I'm over. I can add some of these if there is interest (IIRC, PE only post out UPS, so spreading the US postage cost might make it worthwhile). If someone wants to spin up a group buy DM I'm fine with couriering... but I'm not looking to get any for me.
Posted by: croissantking on 2024-03-14 08:15:07 This week I successfully installed a salvaged 68040 on my PowerBook 520c daughtercard, replacing the LC040 chip it had before. It boots and the FPU is detected. See the thread here: https://68kmla.org/bb/index.php?threads/powerbook-500-series-full-040-cpu-swap.46910/
Posted by: croissantking on 2024-04-06 08:03:48 This is something of an anti-conquest… I extracted the 40MHz 040 chips from my two Quadra 840AV boards and one of them seems to have been hit by battery acid. The corroded pins are just about ready to drop off and indeed one already has just from the slightest touch. I guess there’s no way to save this? A shame, because genuine 40MHz parts are not commonplace.
Posted by: croissantking on 2024-04-06 08:51:33 Meanwhile, my 3D-printed CD-ROM bezel for the case looks like it's been a win. Of course I'd prefer an original bezel, but considering that they're basically unobtainium at this point, I'm really happy. The plan is to retrobrite the case, then spray the bezel to match.
Posted by: treellama on 2024-04-06 09:40:51 This is something of an anti-conquest… I extracted the 40MHz 040 chips from my two Quadra 840AV boards and one of them seems to have been hit by battery acid. The corroded pins are just about ready to drop off and indeed one already has just from the slightest touch. I guess there’s no way to save this? A shame, because genuine 40MHz parts are not commonplace. I bought a repaired 68040RC40 from Herb Johnson. I don't know who he got to repair it, but there is someone out there who is able to do it.
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