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PowerBook 500 Series full 040 CPU swap
Posted by: Durosity on 2024-03-20 15:14:13 You definitely should! I’m guessing this mod could be applied to the 190 and the Duo 280c. I was thinking that too.. actually I’m thinking if you took a 190 and replaced its screen with an active one from a 5300 (maybe even a CE?) and gave it a full 68040 you’d pretty much have the best portable 68k machine!
Posted by: 3lectr1cPPC on 2024-03-20 15:34:18 (maybe even a CE?) It would work.
Posted by: CC_333 on 2024-03-20 21:26:17 the best portable 68k machine The best portable 68k machine, in my mind, would probably be one whose plastics aren't crumbling and whose hinges (if a laptop) haven't failed. Does such a model exist? I don't know. I sort of doubt it.... c
Posted by: croissantking on 2024-03-21 08:30:47 I sourced another of these CPUs, this time a Freescale MC68040FE33A, L88M mask. It’s on a donor board so is likely to be genuine. I think it should work - stay tuned for more surgery.
Posted by: 3lectr1cPPC on 2024-03-21 08:31:34 Are you going to use a second daughtercard for that? I wouldn't risk the same one if I were you.
Posted by: croissantking on 2024-03-21 08:33:22 Yeah, I have two more daughtercards with LC040s, I will keep the first one intact.
Posted by: Durosity on 2024-03-21 15:41:01 The best portable 68k machine, in my mind, would probably be one whose plastics aren't crumbling and whose hinges (if a laptop) haven't failed. Does such a model exist? I don't know. I sort of doubt it.... c Oh indeed.. I think the plastic on every PowerBook ever made is starting to crumble now, especially the ones made around that time.
Posted by: 3lectr1cPPC on 2024-03-22 10:49:47 PowerBook 100’s plastics are still holding strong (about the only part of that thing that is) Plastics aging are just a part of old laptops. Coming from someone who collects a lot of PC laptops I’ll just say one thing - be glad that you can reliably fix the hinges on these with a bit of work and 3D printing. Compared to how bad hinge failures can get on some PCs, the PowerBook 500 can look like it deserves a build quality award.
Posted by: croissantking on 2024-07-12 01:59:22 Just done another successful full 040 upgrade, this time with a Freescale chip. It’s a L88M mask, I’ve heard these run cooler than the E31F?
Posted by: jmacz on 2024-07-12 10:43:38 Is that a 25MHz part? Did you put it on a 520/520c daughterboard (25MHz) or did you downgrade the crystal too? This is awesome. Need to look into this at some point 🙂
Posted by: croissantking on 2024-07-12 10:47:26 Is that a 25MHz part? Did you put it on a 520/520c daughterboard (25MHz) or did you downgrade the crystal too? This is awesome. Need to look into this at some point 🙂 I put it on a 33MHz card and downgraded the Crystal. Do you remember I previously swapped in another full 040? I yesterday overclocked it to 33MHz and am testing it now for stability.
Posted by: jmacz on 2024-07-12 10:49:49 Yup, I remember. Since it looks like my overclocked LC040 is holding steady at 40MHz, do you think a faster full 040 (faster than 33MHz) with appropriate clock chip would work? Must be a pain to solder each of those pins!
Posted by: croissantking on 2024-07-12 10:59:39 Yup, I remember. Since it looks like my overclocked LC040 is holding steady at 40MHz, do you think a faster full 040 (faster than 33MHz) with appropriate clock chip would work? Must be a pain to solder each of those pins! I don’t think there are any 68040FE chips faster than 33MHz in existence, at least not with the A or M suffix. I think it would work if you fit a 33MHz part and overclock it to 40MHz, though? I haven’t been able to get hold of anything faster than a 25 yet - although I understand the mask is more important than the speed rating in determining how far you can push it. Soldering ain’t the easiest job - the pins are really fragile and easily bent.
Posted by: jmacz on 2024-07-12 11:01:09 I see. Will look into this once I exhaust my current projects.
Posted by: croissantking on 2024-07-12 11:39:31 I stuck a 20MHz crystal onto my L88M card. It works fine, except I still can't boot with either of my 32MB cards installed (but a 16MB card works fine). I ran into this problem previously. I don't think it's an issue with the CPU, rather I think my RAM can't handle a 40MHz CPU bus.
Posted by: zigzagjoe on 2024-07-12 11:55:51 Basically any 040 made with a datecode of 94xx or newer should be able to run at 40mhz without problem as long as cooling is sufficient. So I'd not worry about swapping xtals on them. Interesting that your freescale 68040 has a datecode of 8th week of 2016 though. L88M should, in theory, run slightly cooler/require less power due to node shrink, but in application it is an incremental improvement, not the apocryphal "runs cool to the touch" that has been floated in the past.
Posted by: jmacz on 2024-07-12 12:06:42 I stuck a 20MHz crystal onto my L88M card. It works fine, except I still can't boot with either of my 32MB cards installed (but a 16MB card works fine). I ran into this problem previously. I don't think it's an issue with the CPU, rather I think my RAM can't handle a 40MHz CPU bus. That's interesting. My stock 33MHz CPU is working fine at 40MHz with my newly modified 32MB memory card (which I believe is essentially the same card as yours -- and has the same donor chips too).
Posted by: croissantking on 2024-07-12 12:11:32 Interesting that your freescale 68040 has a datecode of 8th week of 2016 though. Yes, wasn’t that after the NXP merger? That's interesting. My stock 33MHz CPU is working fine at 40MHz with my newly modified 32MB memory card (which I believe is essentially the same card as yours -- and has the same donor chips too). Yeah. I’m not sure what to make of it really. Are your chips 70ns?
Posted by: zigzagjoe on 2024-07-12 12:13:43 Yes, wasn’t that after the NXP merger? Yeah. I’m not sure what to make of it really. Are your chips 70ns? Not quite sure... I mostly know about 68030 and 68882 in detail. So I'm not able to validate by looking at markings. Might be worth testing the marking on the chip with isopropyl/acetone.
Posted by: croissantking on 2024-07-12 12:22:42 Not quite sure... I mostly know about 68030 and 68882 in detail. So I'm not able to validate by looking at markings. Might be worth testing the marking on the chip with isopropyl/acetone. It’s legit. It came to me on an old piece of donor PCB, the FPU works and the marking on the chip doesn’t come off with IPA.
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