allthingsanalog
pfm Member
Just watched this. The most insane but brilliant piece of recreation of retro computing I’ve ever seen.
It’s quite brilliant.
It’s quite brilliant.
Vintage computer fun
- Thread starter Tony L
- Start date
suzywong
Wot, no electrons?
For cleaning purposes, I’ve had good results with careful application of white vinegar from Tesco. Applied sparingly with a Q-Tip and watched carefully before rinsing off. PITA, and takes multiple applications, but has restored some seriously corroded Lego Mindstorms processor/battery units.
david ellwood
Kirabosi Kognoscente
Just wow!
allthingsanalog
pfm Member
Exactly. The skill was incredible.
Tony L
Administrator
And depressing just how poor 3d printing is even now with what looks like a pretty expensive machine. The guy had stunning CAD skills, he seemed to nail every aspect of a remarkably complex case design (Apple’s case has to have been pushing injection moulding technology close to its limits), yet it required so much filler, so much sanding etc.
I came to the conclusion a long while ago that the sort of 3d printer I could afford is of absolutely no interest to me as the end product is just so naff. If I wanted anything done I’d pay a company such as PCBWay to do it on a state of the art machine. Their resin prints are not far away from injection moulding quality now.
cutting42
Arrived at B4 Hacker Ergo
Good comment, I know from some friends use that print speed make a huge difference with quality. Maybe with such a large print a higher quality would have take significantly more time. It was 48 hrs I believe, maybe the next quality level was 2 weeks?
I dismantled everything down to the regulator board, brought it up with nothing connected and sensible looking voltage rails appeared (+/-24v, +12v, +5v). I reconnected the display, and it powered up, with a flash on the screen so the screen looks to be fine.
Next up, put the boards back in, and try like that. This is interesting, the display shows a signal which looks a bit like a loss of horizontal sync, so there is a block of characters and some flickering, but if I disconnect the video signal then reconnect with the machine running, it works, in the sense of I get a solid(ish) display. There's a flashing cursor, and typing on the keyboard gives an updated set of characters. Unfortunately the character set which i'm guessing is in ROMs on the display card look to be junk.
Here's the sort of thing you end up with:
So, i'm guessing the memory and processor boards are ok, and enough of the display card and VDU to give something. Next up, i'll get an oscilloscope on the lines to the VDU and see if the voltage levels are way off (there are some adjustment pots to set levels) and i'll do some guessing as to what they adjust.
I'll then look at the display card and try and work out what is going on, hopefully the parts will give me an idea what the likely arrangement is. I believe it's going to be something like 40*25 character display, so 1K of video RAM, and probably a minimal character set in ROM.
Next up, put the boards back in, and try like that. This is interesting, the display shows a signal which looks a bit like a loss of horizontal sync, so there is a block of characters and some flickering, but if I disconnect the video signal then reconnect with the machine running, it works, in the sense of I get a solid(ish) display. There's a flashing cursor, and typing on the keyboard gives an updated set of characters. Unfortunately the character set which i'm guessing is in ROMs on the display card look to be junk.
Here's the sort of thing you end up with:
So, i'm guessing the memory and processor boards are ok, and enough of the display card and VDU to give something. Next up, i'll get an oscilloscope on the lines to the VDU and see if the voltage levels are way off (there are some adjustment pots to set levels) and i'll do some guessing as to what they adjust.
I'll then look at the display card and try and work out what is going on, hopefully the parts will give me an idea what the likely arrangement is. I believe it's going to be something like 40*25 character display, so 1K of video RAM, and probably a minimal character set in ROM.
Screen update - the display uses a standard MCM6571 character generator, and by running the board with no CPU, I can get it booting with rubbish in it's display memory, and various characters appear, so the problem isn't the characters. Next up, the memory on the board is socketed so I removed it, gave the sockets a clean and reseated the memory, and the display problems changed. It's apparent that there's a dodgy memory chip (8 1kbit SRAM chips, 1 appears to be bad). Swapping them around, I can get text to turn up:
So it's running ZEBRA V01 (the numeric characters have a bit set wrong, assuming it's ascii it's ended up +0x40, space also maps to ` when that bit is set)
The display doesn't have a consistent horizontal sync, it waves about a bit, but looking at the sync line from the video card on a scope it looks rock soli, as does vertical sync, a nice steady 50Hz. It also doesn't latch on start correctly, so i'm going to guess there are dodgy caps on the display end. There are also some flickering spurious characters in the output, i'm guessing display board capacitors too.
So, lots of caps to go through will be the next step, and i've got a replacement 1978 SRAM on order to hopefully fix the character set.
So it's running ZEBRA V01 (the numeric characters have a bit set wrong, assuming it's ascii it's ended up +0x40, space also maps to ` when that bit is set)
The display doesn't have a consistent horizontal sync, it waves about a bit, but looking at the sync line from the video card on a scope it looks rock soli, as does vertical sync, a nice steady 50Hz. It also doesn't latch on start correctly, so i'm going to guess there are dodgy caps on the display end. There are also some flickering spurious characters in the output, i'm guessing display board capacitors too.
So, lots of caps to go through will be the next step, and i've got a replacement 1978 SRAM on order to hopefully fix the character set.
Tony L
Administrator
My trusty mid-2012 i7 Macbook Pro has finally earned retirement and a place in my vintage computer menagerie. Best computer I’ve ever owned by miles. A design classic IMO. The last upgradable Macbook and loaded with its 16GB of RAM and 1TB SSD it is still a really competent performer. I’ve only reluctantly replaced it as it is becoming too orphaned and far from software support for what is at core my business machine. I only hope its replacement (an absurdly expensive M3 Pro MBP) proves anything like as long-lasting.
I thought long and hard about rebuilding the old MBP with Linux, but that would mean losing Logic and all the easy integration with the other Apple iThings. I felt physically sick pressing the ‘buy’ button on the new one, but I got in end of last tax year so can write a good percentage off, but its done and the new one seems very nice. It’s the 18GB ‘binned’ M3 Pro upgraded to 1TB SSD, so RAM and storage very similar to the one it replaced. Moore’s Law has collapsed in any real sense over the past 15 years IMHO, computers have been fit for most users purpose for a long while now. A very different thing to the old 8088 through to Pentium days when stuff either started to choke or wouldn’t run at all after a year or 18 months. It is OS and app lock-in that limits life now. Certainly with Apple and Microsoft.
I’ve just boxed the mid-2012 Macbook. I plan to keep it as it is very, very close to mint (I always used it with my Model M, so the keyboard isn’t worn etc). Can’t decide whether to take the battery out or not. I may do after a few months, I won’t yet as it is a useful full backup at present, including my 560GB iTunes library which I’ve decided to abandon. Makes no sense in a modern streaming world. I’ve only brought my own stuff (old band demos, Logic projects etc) over to the new one. End of an era…
PS No, I didn’t buy the M3 in trendy black. I suspect that will look like crap in 10 years with bright marks round the ports etc! It is the same silver of the one it replaces!
I consider those MBPs to be the last true "professional user" laptops that Apple made. Everything since has been compromised.
I used to use Macs exclusively (my first two jobs were at Motorola so long ago that they still used Macs, then five years or so at Apple), but the first job I had where I was issued with one of the Dell enterprise models was a revelation: clip it into a cradle and your keyboard, monitors, mouse, charger and network are all connected. But contrast, every "dock" I've seen for Apple laptops turns out to be a Heath-Robinson thing that just does not work properly: my boss at a more recent job must have bought every single one of them before eventually giving up on the idea.
It is amazing how Apple's legendary "design brilliance" can't produce any kind of port replicator or docking system for their laptops, though.. especially now that all they'd need to expose are the Thunderbolt/USB3 pins. (But if you open one up, you'll see why this is...)
I used to use Macs exclusively (my first two jobs were at Motorola so long ago that they still used Macs, then five years or so at Apple), but the first job I had where I was issued with one of the Dell enterprise models was a revelation: clip it into a cradle and your keyboard, monitors, mouse, charger and network are all connected. But contrast, every "dock" I've seen for Apple laptops turns out to be a Heath-Robinson thing that just does not work properly: my boss at a more recent job must have bought every single one of them before eventually giving up on the idea.
It is amazing how Apple's legendary "design brilliance" can't produce any kind of port replicator or docking system for their laptops, though.. especially now that all they'd need to expose are the Thunderbolt/USB3 pins. (But if you open one up, you'll see why this is...)
Tony L
Administrator
I’m slowly building a nice collection of USB C to whatever cables! I have one of Apple’s overpriced USB C to female A dongles, but I’m keeping that on the Model M. Thankfully USB cables are cheap. I’ve got the external SSD drives sorted. I need a C to B for my Focusrite 2i2 mic/line input and fairly long C to whatever the UMIC REW mic uses (I’ll have to dig it out and check). I think that’s it.
FWIW Apple’s Migration Assistant did a really good job, which surprised me given how old Mohave (on the mid 2012 machine) is. I planned to do a completely fresh install of everything from scratch, but took one look at the nightmare that is my email system and thought “screw that”. I can’t remember how most of it works and I’ve forgotten the passwords for half of it!
To be honest it is another ‘problem’ with Apple; they make staying in the ecosystem so crazy easy the thought of migrating elsewhere just looks like a whole world of hassle and pain. This is my fourth migration (G4 Macbook, 1st gen Unibody, mid-2012 and now M3). I’ve never done a full flatten and rebuild the way I did back when I was a Windows user. I did it pretty much annually then as things slowed down so much!
Agreed. I rate it as the best computer I’ve ever personally owned. The next best would be the BBC Micro!
Well apple did do this for a number of years, with the Duo Dock which was like a large VCR for your laptop, sitting under your office monitor with keyboard/mouse etc connected:
Duo Dock
The Macintosh Duo Dock is the original full-size docking station that was developed by Apple Computer and released on October 19, 1992, along with the PowerBook Duo 210 and 230. It was superseded on May 16, 1994 by the Duo Dock II. Both of the preceding full-size docks were replaced by the Duo...
It's an obvious idea, and i'm kind of surprised that there isn't really anything quite like this around today
On the subject of old computers, and macs is particular, i've just picked up a Mac IIcx, which was the first mac i owned (back in 1991). This one is broken, but the motherboard is in decent looking shape, so I suspect it's power supply issues. I've had a dig around in old boxes of useless bits, and i've found an ADB mouse, 16mb of 30 pin SIMMs, a nubus graphics card, and what I suspect is a boot SCSI drive from when I used to own one before. One of the few benefits of being a hoarder 
The power supply looks ok, but it's got some cracked X and Y capacitors, so there's some rifas or equivalent to sort.
The power supply looks ok, but it's got some cracked X and Y capacitors, so there's some rifas or equivalent to sort.
Tony L
Administrator
On the subject of old computers, and macs is particular, i've just picked up a Mac IIcx, which was the first mac i owned (back in 1991). This one is broken, but the motherboard is in decent looking shape, so I suspect it's power supply issues. I've had a dig around in old boxes of useless bits, and i've found an ADB mouse, 16mb of 30 pin SIMMs, a nubus graphics card, and what I suspect is a boot SCSI drive from when I used to own one before. One of the few benefits of being a hoarder
The power supply looks ok, but it's got some cracked X and Y capacitors, so there's some rifas or equivalent to sort.
If you haven’t found him check out Mac84 on YouTube. You’ll find loads of content about fixing up these. Beige Macs are totally his thing!
His first episode is with a IIcx, so some content for me to trawl through, thanks for the tip!
I thought i'd mention where I am with my Mac IIcx.
I dismantled the power supply, and there was nothing particularly terrible going on, nothing obviously leaky, so I replaced the rifas, which had cracked after 35 years, which is fair enough:
As I mentioned before, i found a battery, 30pin SIMMS and a video card from when I owned one originally, and these went in ok. I replaced the SMD capacitors on the board, they looked ok, but there is some corrosion which might be a leak, so I cleaned the board and replaced them as these are cheap and there are only 11 in total. There was one corroded pad for one capacitor, which either I damaged removing it, or had disintegrated, hard to tell.
The machine is quite elegant when assembled, and not very heavy. If you compare this to the clunky PCs at the time, this looked like an alien artefact:
As of now, it powers up from the push button, makes the correct startup beep, and checking on an oscilloscope there is something sensible coming out of the video card, so i'm thinking it's likely to be close to working. I've plugged in what I thought was a boot SCSI disk for it, and it makes the right spinny up noises, but then clearly doesn't find anything suitable. I'll have another dig just in case i've got a drive for it elsewhere.
I also realised I had a contemporary copy of PCW which I kept as it had a review of the machine.
So, next up, find a suitable ADB keyboard (I really want the compact one I had at the time). I've found the mouse. Find a suitable DB15 video adapter, or ideally an apple trinitron 14 inch monitor which sits nicely on the top. I've also got to track down suitable external SCSI cables to connect the CD ROM drive i've found, as I think I have a big bundle of software for it on CD...
One other thing, the case sides are discoloured compared to the top, so I think there is some plastic cleaning to learn about, and see if I can bring it back to it's original colour.
I dismantled the power supply, and there was nothing particularly terrible going on, nothing obviously leaky, so I replaced the rifas, which had cracked after 35 years, which is fair enough:
As I mentioned before, i found a battery, 30pin SIMMS and a video card from when I owned one originally, and these went in ok. I replaced the SMD capacitors on the board, they looked ok, but there is some corrosion which might be a leak, so I cleaned the board and replaced them as these are cheap and there are only 11 in total. There was one corroded pad for one capacitor, which either I damaged removing it, or had disintegrated, hard to tell.
The machine is quite elegant when assembled, and not very heavy. If you compare this to the clunky PCs at the time, this looked like an alien artefact:
As of now, it powers up from the push button, makes the correct startup beep, and checking on an oscilloscope there is something sensible coming out of the video card, so i'm thinking it's likely to be close to working. I've plugged in what I thought was a boot SCSI disk for it, and it makes the right spinny up noises, but then clearly doesn't find anything suitable. I'll have another dig just in case i've got a drive for it elsewhere.
I also realised I had a contemporary copy of PCW which I kept as it had a review of the machine.
So, next up, find a suitable ADB keyboard (I really want the compact one I had at the time). I've found the mouse. Find a suitable DB15 video adapter, or ideally an apple trinitron 14 inch monitor which sits nicely on the top. I've also got to track down suitable external SCSI cables to connect the CD ROM drive i've found, as I think I have a big bundle of software for it on CD...
One other thing, the case sides are discoloured compared to the top, so I think there is some plastic cleaning to learn about, and see if I can bring it back to it's original colour.
Found a monitor that worked with the graphics card, found mouse, bought a period correct keyboard:
Tried making some boot floppies without success, and can't find a suitably formatted hard disk in my collection, so some progress. I'll also need to spend some time sorting the plastics as they are all rather yellow
Tried making some boot floppies without success, and can't find a suitably formatted hard disk in my collection, so some progress. I'll also need to spend some time sorting the plastics as they are all rather yellow