0045 ROM/RAM replacer for Z80 machines, a long lost Turbo XT manual, a Leading Edge laptop and more
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- Опубліковано 1 жов 2024
- On today's video, we have another interesting assortment of items including a the hotly awaited new Z80 romulator!
-- Video Links
Mitac MPC-160T User Manual:
archive.org/de...
Mitac MPC-160T Floppy DIsk Images and System Utilities:
archive.org/de...
FormatQM (to bulk format floppies)
vetusware.com/...
Using the ROMulator (for the 6502 VIC-20)
• Replace your 6502 comp...
Using the ROMulator (to do a PET repair)
• Let's troubleshoot and...
Adrian's Digital Basement Merch store:
my-store-c82bd...
Support the channel on Patreon:
/ adriansdigitalbasement
Adrian's Digital Basement (Main Channel)
/ @adriansdigitalbasement
-- Tools
Deoxit D5:
amzn.to/2VvOKy1
store.caig.com/...
O-Ring Pick Set: (I use these to lift chips off boards)
amzn.to/3a9x54J
Elenco Electronics LP-560 Logic Probe:
amzn.to/2VrT5lW
Hakko FR301 Desoldering Iron:
amzn.to/2ye6xC0
Rigol DS1054Z Four Channel Oscilloscope:
www.rigolna.co...
Head Worn Magnifying Goggles / Dual Lens Flip-In Head Magnifier:
amzn.to/3adRbuy
TL866II Plus Chip Tester and EPROM programmer: (The MiniPro)
amzn.to/2wG4tlP
www.aliexpress...
TS100 Soldering Iron:
amzn.to/2K36dJ5
www.ebay.com/i...
EEVBlog 121GW Multimeter:
www.eevblog.co...
DSLogic Basic Logic Analyzer:
amzn.to/2RDSDQw
www.ebay.com/i...
Magnetic Screw Holder:
amzn.to/3b8LOhG
www.harborfrei...
Universal ZIP sockets: (clones, used on my ZIF-64 test machine)
www.ebay.com/i...
RetroTink 2X Upconverter: (to hook up something like a C64 to HDMI)
www.retrotink.com/
Plato (Clone) Side Cutters: (order five)
www.ebay.com/i...
Heat Sinks:
www.aliexpress...
Little squeezy bottles: (available elsewhere too)
amzn.to/3b8LOOI
--- Links
My GitHub repository:
github.com/mis...
Commodore Computer Club / Vancouver, WA - Portland, OR - PDX Commodore Users Group
www.commodorec...
--- Instructional videos
My video on damage-free chip removal:
• How to remove chips wi...
--- Music
Intro music and other tracks by:
Nathan Divino
@itsnathandivino
The miniature fluorescent tubes used in backlights go dim after a while. You might be able to replace them with LED strips. The Signal Path has a video about this: ua-cam.com/video/smrMoIpvYTk/v-deo.html
I agree.
Although color may be bad, for this machine it doesn't matter.
It may be possible that dead line is just bad contact - try massaging the connection point
Ive done this mod on a few machines, I try to find portable DVD players as most weren't used much, and most them have led backlights. Easy to find at goodwill for 5 dollars or so if you are in the US. Early EEE pcs and netbooks are a good source as well.
In a machine of this age with a black and white display, greenish cast, and how thin the display is, I would say it's more likely to be an electroluminescent (EL) backlight layer. The early EL back lights were known for not being very good and wearing out pretty quickly.
@@Cherijo78 Most 3:4 displays were CCFL not EL, unless plasma. If it was a widescreen style text only or CGA and basically a fancy dot matrix I would agree.. Now it could be plasma, which has its own problems, like having to replace the entire display.
@@waytostoned I've run across a few "large" 4:3 displays like this that used an EL backlight over the years. It wasn't as common by the time this machine was sold, but I definitely have seen it in other 1980s LCD displays. That extra green tint I can see right at 26:15 When Adrian puts his hand over the top of the left side of the screen, as opposed to a bluish-white tint that was more common on early CCFLs is what still leads me to think it may be an EL backlight of some kind. But, that could be just the green background on this cheaper LCD panel, and it could be CCFL. It would be very interesting to see it come apart and find out what type of backlight it is, either way, and attempt to repair it! Please take it apart Adrian and show us! Was it really ancient EL backlighting Tech that they were still using on this machine to cheap out on users, or is it CCFL, and can you upgrade it to led? Inquiring minds want to know!
YOU MUST DESIGN THE SOFTWARE YOURSELF. I laughed so hard. It's like a warranty that covers nothing due to the terms.
That's just the way it was back then. If you wanted to do something, generally, you had to write the program yourself.
The C64 didn't give you 64k of memory without doing the same thing...
True, but all you need is a zip drive, a bootable floppy disk with at less MS-DOS 5 or higher, zip drive drivers on that same floppy, and what ever XT compatible software on the zip disk. Borland Pascal, Borland c++ 3 or old would work. The biggest problem is how to get the vga port working.
That's the kind of thing that gets written after being inundated with complaints about "WHERE'S MAH OTHER 128K?!"
warranty only covers the hardware side of the computer, it doesn't cover problem with software. What wrong with writing code, as long as you are willing to do that.
Thank you for the video and your recollections of Ketchikan! Glad you were able to get my old laptop fired up. I don't recall the screen being so dim, so sorry about that. I wonder if the sense lead turns the backlight on when it detects a higher voltage coming in. IIRC, the onboard HDD was a Type 6 or 7, that I had to set repeatedly due to the expired BIOS battery. Thank you for giving it a fighting chance and feel free to donate it as you see fit. 🙂
Hi Adrian! Great video as usual, thanks for taking a look at the ROMulator Z80! I hope to get bank switching working with it in the near future. The hardware should support it, but as you mentioned, that's something that requires individual handling for different Z80 systems, so it's difficult to generalize. And sorry about that mega sticky tape!
As it turns out, I actually disassembled and rewrote the Mitac speed control tools back in April. Setting the speed was done by outputting 0x7F (slow) or 0xFF (fast) to port 0xC0.
Basically toggling bit 7 on that port.
@@Renville80 Most likely.
I had a laptop that would only power the external screen if the lid was closed on power on. I think it treats it like it's 'Docked' in that mode. So plug in a keyboard and monitor, then power it up. That will probably trigger the external monitor.
the back light in those older laptops were CCFL fluorescent tubes and they die over time. I have personally replaced them in a screen. the CCFL's were about 15 bux for the pair and it took about 90 minutes to do the job as I had never done it before.
Oh man, I work for xerox, I'd love to have some of those! I just looked up the part number in our software, and sure enough it's still listed. I'm sure I won't ever get them if I were to order them, but it's kind of wild that the part number still works!
Verbatim had a range of discs with 'extra' mould inhibitor in the binder that held the magnetic material on the disc. I worked at a computer shop for a couple of years in the 80s and they were a quite popular line. Living in the tropics, North QLD Australia, meant a lot of discs went mouldy just sitting the sleeve. I think they came in blue sleeves instead of the then pink/red sleeve.
Mold the mold.
That's useful to know. ☺Here in (at least this part of) England the relative humidity often hits 100%, which is not all that good for disks (some of my DD ones are having issues reading) or my lungs. ☹ Surprisingly the HD ones all seem to be OK, which seems contrary to some reports I've seen. I do have some Verbatim disks; will check to see if any of those have the extra mould inhibitor.
I had a Victor branded 386SX laptop with very similar styling, probably made by the same Korean OEM. It wasn't anything fancy, but it worked fine for WordPerfect and other apps I was using in college. While I remember the screen being really clear that was probably just in comparison to the Sharp PC-4500 I used previously.
you should do a led strip retrofit for the lcd, they sell kits for it
That Z80 Romulator sure would be useful on a Coleco Adam... 🙂 Great video as always!
Hi Adrian ,
Basements are rare in Arizona. This I primarily due to a hard substance called caliche. It is like a natural cement in the ground itself. It makes digging both expensive and difficult. I moved from New York State where basements are a normal thing there. I miss having a basement.
So, a little computer story from Alaska. My friend's Grandpa's first computer was an original Apple 1, which already is pretty cool, but it was also the first computer in his city up here, and probably one of the first computers in Alaska, especially of that vintage. I don't really know much more, other than it was in the Matsu Valley, but yeah.
Just a point of order, later Spectrum models from the 128K onwards (including all the Amstrad ones) *did* use bank switching to access all their RAM.
I know the C64's 64K was pretty much the maximum without switching. In fact, if you didn't switch out the ROMs and use some tricks you couldn't even use the full 64K of RAM. The inconvenience of bank switching was why the C64 RAM expansions had a chip which helped move RAM around quickly.
Of course, a Z80 has a 16-bit address bus, so in order to access more than 64K you need bank switching, it's not possible to make it directly.
Unless the wilderness has a 230V outlet, a bathroom, and room service, I have no interest in it.
It's not just the display tech - the CCFL bulb is finished! You should make a video of replacing that and give this old girl a chance.
The extra memory would have been useful for all sorts of productivity software (e.g. databases). It also could have been used to hold "overlays" (sort of like a .dll file) for programs that used overlays for some of it's software.
Those early LCD displays were only borderline usable when new and the years haven't helped. The place where I worked bought one of the first PC compatible laptops for engineers to be able to take along on customer visits. but the display was so poor it wound up sitting in a storage room and engineers kept lugging their desktop machines/monitors along for a few more years while laptops improved.
Advert: Our clone PC has 128k more RAM than the leading other clone!
*Later, after buying: Oh, you actually want to use that extra ram? Good luck.
Hmm… at this point, would that be a Trailing Edge laptop? 🤔
More like a Over the Edge Laptop.😂🤣
I think basements in Arizona are rare for the same reasons basements here in Texas are rare, despite the need for storm shelters. Anything more than 5 or so feet down is clay and full of rocks. It makes digging basements difficult and time consuming. You can nearly double the cost of building a new house here if you want a basement. Plus, because of how bad flooding can be in the fall months, having a basement is a huge liability.
For the laptop power supply I noticed that you had your ground probe on the outer shell of the 4 pin connector. Usually this is not connected to ground on the adapter and I suspect that is why you were not getting any voltage out of it. If you measure for voltage between the pins on the connector you should get a reading. If you are not sure which pins are ground you can install the battery back into the computer and measure with your meter on ohms between the the 4 pins and the grounded shield on the ports on the laptop. I am going to guess that there is going to be two ground pins, a sense pin for the battery charge indicators and a power pin.
LCDs on laptops back in the 80s and 90s were dreadful, the worst I've used is the Acorn A4 laptops we had at school (late 90s, early 2ks, long after Acorn was pretty much defunct!), they had to be looked at perfectly square-on, otherwise it looked like a technicolour headache, often causing one too!!! Those things were basically an Acorn stuffed inside an Olivetti 386 laptop case, and were just as dreadful to use as the desktops (speaking as a PC/Amiga user!!!)... :S
Cool video! Bitfixer makes great tools for 6502 and now Z80 which are fantastic and is great for your bag of diagnostic tools. Thanks for sharing.
I wish new laptops came with nice keyboards like that ancient laptop appeared to have.
The Z80 ROMulator is channel one stuff. 😂
When I was a kid, we had a small number of disks with the same Xerox sleeve/label. One was our boot disk, so it was out all the time, and I had always assumed that the fading was a result of being left out. Seeing this video makes me wonder if it was a common printing issue.
That looks similar to the 486sx I did on my channel, it needed a program to enable the external monitor. Ill put money on it being the same application for that one if you want me to send it over.
Is there a Switch next to the VGA Port to enable it?
Oh my god that Targa bag! So many memories of my old laptops. I had a Toshiba in one exactly like that one
Don't know about that battery, but I usually place laptop power supplies on something solid and tap the joining seam with a hammer and you'll hear the glue cracking, ie, it separating.
Wow, the screen looked easier to read on the camera for once! Hard to say if the screen would be easy to fix/replace.
Moldy discs can be cleaned with soap and warm water once extracted from their sleeves, if you want to recover some sort of rare software or documents. The ones with decayed media-binder are unfortunately usually a lost cause.
I need to set up a computer to backup all my old floppies and write them to CD for safekeeping, while they still work!
Almost got an old XP laptop set up to run my Eprom programmer/reader, got a lot of old chips to read and backup!
The DOS disks also seem to feature a version of VDISK that supports the banked RAM.
Hi Adrian. Instead of doing a video on historic computers (like the SWTPC “box”), maybe you should do a video (on your other channel) on the history of gummi candy. 😂 On a more serious note, have you been following “Usagi Electric”s channel where he gets a clunky old 8” floppy drive connected to a DEC mini-computer? It looked a lot like the 8” drive from your TRS-80 Model II.
What’s that switch on the right that says:
“INT” and “EXT”
Right by the brightness and contrast controls.
I thought the same but reviewed the video and saw that it is for the keyboard.
@@PaulinesPastimes it could be both.
Oh yeah, those backlit twisted nematic LCDs were terrible. The super twisted nematic LCDs were much better. There's a chance you could find a similarly sized CFL tube to replace the old one, but it would probably require quite a bit of hacking, and chances are you'd just end up breaking the case plastics trying to take it apart.
My first laptop, a NEC from 1986-1987 (by chip dates) or soon after reads on the back 13 V for the external power. However, it has 9 V pack of NiCad batteries. Instead of the manual info, the CPU chip is NEC V30, not V40. It sports 2 floppy disks of 3.5" and a RAM disk (C) of 120 kB. The display is WITHOUT any backlight, just a type that reflects part of the ambient light through the LCD at the mirror layer behind the active layer(s). But I concur with another comment that pointed towards the common fluorescent lights used as backlight in those days. You might either replace the fluorescent tube(s), or modify the display backlight with a number of LEDs.
Yeah, i worked at a computer seller back in the early 80's, and the laptops were pretty terrible. Heavy, big, very limited battery life, and the screens were horribad. But that was the price we had to pay for the amazing LCD monitors and TV's we have today.
That and portable electronics was and is a real driving force in battery technology.
So while these machines are horrible in today's terms, we owe a lot to these early machines for pushing the envelop and enabling the fantastic things we enjoy today.
McDonalds in Alaska? So… frozen McNuggets and Oreo Flurries that don’t need the machine working to be frozen? 😉
That laptop battery design is really stupid, IMO. :) I have a Windows 3.2 laptop with a similar screen but the backlight has stopped working compleately. If I want to use it I have to sit outside with the sun behind me shining on it, it shows up perfectly then. LOL.
I have an old laptop that won't work at all with the battery pack or the CMOS battery installed. It's a brilliant XP machine though.
I have quite a few laptops, all with little quirks and issues. Ha ha.
Oooh, I could use the Turbo XT Manual! (I'm trying to use as many XT manuals as I can to try and get an idea about upgrading the RAM on a rare Sanyo MBC-775!) :D Could you scan that and post it sometime?
Adrian, that Leading Edge laptop is definitely a 386SX running at 20MHz and 2MB RAM.
For the Leading Edge laptop try alt+ctrl+d to select an external monitor. If that doesn't work try another alt+ctrl+(letter). I can't remember what letter to use, but I do remember the alt+ctrl+(key) combo.
Adrian! I love your stuff but for the love of all that is holy, STOP flailing like a madman with the stuff...we do enjoy seeing the stuff you are handling
Leading Edge was actually subsidiary of Daewoo Group when this laptop was made.
Adrian: *Tries to charge long dead laptop battery*
Also Adrian: Oh...the power supply must be bad!
The battery must need to be able to hold a charge to even run through the power plug.
The internet says "FN-T" to activate/deactivate the external video on a Leading Edge laptop. Your Mileage May Vary.
Gasoline melts the glue on modern Chinese power bricks, search for a video called "How to open up a glued Apple power adapter" from The Tinkering Dad channel, he shows a clean way to open it and unlike others he waits long enough for the gasoline to make effect, many people do not have patience and just after applying the gasoline they pry with a screwdriver damaging the plastic.
For reference, the presence or absence of basements is mostly related to the local frost line- you have to put the building's "footings" below the frostline, and if you have to dig e.g. 6 feet deep in the first place, then you might as well finish digging enough to turn it into a basement. In contrast, if you only have to dig 2 feet for your footings, then digging a basement increases the cost much faster than just buying a bigger plot of land.
Perhaps you could add "Shot originally in August" to give context to the hot weather in Arizona. :)
The 6502 is actually a cutdown MC6800 processor.
I have a Dell 486DX 100MHz laptop from like 1995 with an almost dead TFT display in it. I was just thinking today it would be dynamite to get a brand new IPS panel in there instead. There are so many now that people use for replacing portable game consoles that I figured maybe there is one the size the Dell (it's like 10.25"), but I haven't had a chance to look yet
There's plenty of LCDs on aliexpress and such. The issue isn't so much finding one of the right dimensions, but finding one that is the right size AND the right resolution AND can accept the video signals from the computer. Unless you want to kludge it and use the VGA output. I haven't seen anyone yet who makes a moden LCD swap the "proper" way.
My first computer was a Leading Edge. It's in my dad's attic. I need to fire it up and see if it still works.
Was I only one who could hear the high pitch noies while it was charging 😞 that's a good mic! I am 50 year old man and could hear it.
The laptop could be replaced by a 2S LiPo, which is 7.4V nominal.
I'm not sure I'd want to charge a Lithium Polymer battery on a simple little charger designed for NiCad. My understanding is these lithium batteries require some form of microprocessor to monitor the charge level, and also a microprocessor to monitor the discharge level. The old NiCad batteries excelled at being rugged and taking a lot of punishment, and had relatively simple electronics to recharge them.
@@stevesether Obviously you'd need a balanced charger for that, not the original laptop charger (which seems to not work anyway, based on the video).
@@kardRatzinger The problem isn't only the charger, it's the load as well.
LiOn batteries have a circuit monitoring them so they don't got below a certain threshold. If they do, the recharge circuit won't let them recharge.
So unless you want to add circuitry to the discharge circuit of the laptop, this isn't a simple swap-out old chemistry for new.
@@stevesether That's all true. The minimum voltage of a LiPo cell is 3V, belowe that you're risking damage. A total of 6V is probably too low for a 7805 (if that's what's used in the laptop's voltage regulator) to maintain 5V of VCC. I would speculate that the laptop would shut down before discharging the LiPos below the safe point. Obviously, this requires investigating whether it would work that way for this particular machine, hence the "could" instead of "can" in my original statement.
Hi Adrian, I'm one of your Alaskan viewers! Great Vid too
Would love to see you bring that laptop back to life again.
I found a document that says activating external video on the leading edge is fn+t at least on the dne208.
You can take the ferry from the US. Hi from Bellingham.
Lots of early laptops used electro-luminescent panels for backlighting, these have a very poor life expectancy, and were regarded by some as a 'consumable'
They are relatively thin, so ideal for sliding behind an LCD, but kind of impossible to replace with anything modern. If you are really keen, the light diffuser from an old edge-lit LCD may be shoehorned in - best of luck here.
surprised no one has figured out a way to hook up a modern lcd to a laptop like that for a slightly better replacement
It would be great to se a restoration of this laptop with new backlights and retrobright.
too bad you couldn't try an AT Keyboard on the Leading Edge Laptop
When I lived in Turkey my daughter loved that candy.
Taking notes here: do not send Fruits salad Haribos...
I hope you are ok . Smile if you are hostage or something.
Usually what determines if you have a basement or not is the depth of the frost line.
or if you live near sea level, water table depth...
Maybe the other connection is solely for the backlight?
Oh man, that Leading Edge laptop would be fun to have!!
Why don't you change the back-lit to led? Why don't you put a new isp back-lit screen
You have to understand that from this era the internal video controls are not standard in modern ways. Different vendors didn't follow a standard and everybody pretty much engineered their own. This is a monochrome screen. That laptop might if you are lucky have 1MB of video ram. Even if it could drive it IPS would be a total waste of money. The best you should try to go for it is an LED backlight. As other people have mentioned these use cold cathode fluorescent. And that means either the tube has died or the power supply pushing it has.
The thing I'm betting is that LCD is too new to recognize the feed from the laptop, and the laptop is expecting an external CRT.
someone does make a 7.5in e-ink display......
Hello Adrian,
Do you plan to troubleshoot more modern motherboard units with Intel Pentium 5 or later? I like to watch them as you explain and troubleshoot very thoroughly. I've some stuff on which I am working and that troubleshooting can be of great reference.
I have a sticker that says “you don’t need more than 8 bits”.
Pentium 5?!? Is that a joke or do you just not know?
@@lexluthermiester socket 5 as opposed to 7?
Pentium 5 isn’t a thing and no he doesn’t find stuff past pentium 1 very interesting, not yet anyway
@@aaldrich1982
I don't think that's what they were talking about.
I wonder if the panel is similar to the ones in the SLT286. I have a spare one that works ok. Otherwise changing the backlight tube might be in order.
Try swapping the backlight with thin LED strips. I usually use that on old square working but busted backlight. Maybe it can work? You just need to hook it to a 12v power source.
Similar power arrangement to the Zenith MinisPort. When the battery failed, the computer was useless.
Just guessing (and someone from AZ please chime in), but soil in Arizona might tend to be on the sandy, shifty side which would make digging a basement an expensive proposition.
You might check in with your local Battery World or Batteries Plus store and see if they can get a replacement for you.
While I don't know of any replacement for the screen I have seen some individuals do an LED mod which is a bit fiddly but doable.
Wow, this is a rather problematic laptop. I have an old Toshiba here, but it is at least a pentium one. Although the display is almost as bad as this one (well, it is color, but the refresh rate is a joke).
basement never seen one in austraila mate
With the screen backlight you could replace the electroluminescent sheet that creates the light but it's likely that the capacitors in the high voltage circuit that powers the EL sheet have seen better days.
When you wrote about the A/C turning on, I don't hear a thing but your voice. I thought It was something else.
I would love to tackle that laptop
I guess the whiteish bezel is also washing out what the camera could see of the display on that laptop
The Southwest has tons of wilderness too. Dangerous desert wilderness.
Hello, maybe you can help me, i have been searching the internet a long time but nothing was there about it, so i have a toshiba t1910 laptop with windows 3.1 but it wont start up. I hook it on the charger, turn it on. Then 1 light comes on, 2 other lights and then it turns off. All in like 1.5 seconds. After that the power or charge light (cant remember which one) blinks consistently. Do you know what it is?
I don't know anything about that particular model but maybe it isn't getting enough power. Perhaps the power adapter is degraded.
That extra memory could be used for drivers.
I wonder how hard it would be to replace the screen with modern color! lol
The knife you use, what is the name/brand and where to buy?
Did you forget to put the link to Ravenwolfs channel? Or am I missing it in the description?
Here, if this helps, as I'm a subscriber of his as well
ua-cam.com/users/RavenWolfRetroTech
0:11 Hi!
there is no way that laptop will charge. Batteries that old are going to be dead. But even that wouldn't explain why it won't turn on. Some modern laptops require a working battery. Old ones usually don't.
It probably won't charge but my portable oscilloscope from 1987 (with what I presume is the original battery) was able to charge with a little help. As for needing a working battery, I've heard of systems (IIRC the Macintosh Portable) which float charge the battery and run off of that. I haven't encountered any modern laptops which require a working battery to run.
@@eDoc2020 surprising
wait so you can't swap the battery without shuttind down the computer? Someone didn't think that through. That defeats the prupose of removable batteries.
Since it has a hard drive perhaps it has suspend to disk.
@@eDoc2020 back then that never worked right
the mcu is an esp8266 wifi mcu
I do miss having a basement.
11:07 it's even funnier that Apple copied that battery bump ;)
More than likely both bumps were necessitated by the Cell Dimensions. I've never seen a nicad cell that didn't meet one of the standards of the day. There were no flat cell packs for that chemistry.
Yes, I too am a BYOS PC User lol
16:28 - ow ow ow, left channel missin
16:20 - 16:32 at first I thought my left earpiece was dying on me, but it seems you enabled some kind of paning from center to right? Just so you know ;-)
Yeah that is so strange!! No idea what happened there.
@@adriansdigitalbasement2 I've noticed it on a lot of videos lately. I think there's something screwy on UA-cam's end. I was watching a video last night that suddenly had something like reverb on 45 seconds of the video that I'm pretty damn sure wasn't there.
Haha I thought my ear was full of crap again having a cold. ^^
gatcha can economy
unboxing anything is like a gatcha game
very nice form factor tho
but the lid display could be modern
try my thick-top skeleton case design
also a touch screen + flex key layer keyboard is very slim