Posts tagged "Personal Computers"
These are the entries related to personal computers as opposed to game consoles.
Even after I got it to boot by replacing the video chip, the Casio PV-7 MSX1 still had a bunch of problems. Top of mind were the broken keyboard and the corroded power jack. Let’s fix these issues too, so we can get back to enjoying this el-cheapo computer and the free programs on offer in the manual.
Although it may not be considered an “old” computer, a TI-83+ from the futuristic year of 1999 has a lot of appeal. It’s got a Z80, it runs a BASIC interpreter with machine-language program support, and lots of fun homemade games were built for it over the years. There’s also the small matter of me wanting a desk calculator with which to do binary/hex conversions, so I picked up this broken one to attempt to nurse it back to health. Will my efforts add up to a working calculator?
One of the coolest selling points of the Sharp X1turbo is the built-in “telopper” board. With this board, you can superimpose computer graphics on live TV, and smear dithered-colour games across my tiny Sony CRT. Guess which of the two I’m planning on using it for?
Get ready to step into the cyberpunk future of the mid-late 1980s, and don’t forget to bring your boxed wine. NEC pulled out all the stops on this, their final PC-6001 computer. I have to pull out even more stops to get the disk drive to work.
Even though the X1turbo is working again, it’s not enormously useful right now. Sure, the boot screen is pretty, but there’s so much more to the entire experience. In order to take another step along the road to it becoming a functional computer, I’ll build a keyboard adapter.
Now that the Sharp X1turbo has been convinced to start up again, it’s time to get some video out of it by constructing a cable so it can talk to a more modern monitor. Yeah, that’s right. No ugly dongle PCB this time!
Before the X68000, Sharp had a Z80-based 8-bit personal computer that tried valiantly to compete with the PC-88 and MSX. Actually, they had a couple, but the one that I’m most interested in is the Sharp X1. It combines flash VCR-esque styling, sturdy construction, decent graphics capabilities, and AY-3-8910 sound. What more could you want? Well, you could put the word “turbo” on the front.
You might recall that I own a Sharp X68000 ACE, the world-beating, sprite-spitting computer of everyone’s dreams. So far, though, the ownership experience hasn’t been the most fun I’ve ever had. Repairing the battery damage in mine has been challenging, as the damage goes deeper than I first thought, but I have accomplished one thing so far: installing a more reliable power supply.
With all this discussion of budget Japanese computers and video game consoles lately, it’s easy to forget that I still like old Macs. This Classic II was picked up years ago, and it’s been on the shelf ever since I got it home and spotted the telltale sign of Simasimac. Now that I actually know how to fix it, let’s try to fix it.
One of the more unloved MSX1s is the Casio PV-7. This poor little 8-bit computer was saddled with a crappy keyboard, only 8kB of RAM, no printer port, no built-in tape interface, and only a single cartridge slot. And that cartridge slot doesn’t even follow the MSX standard!
I got ahold of a PC-98 laptop. Unfortunately, it has a lot of battery leakage and won’t power on. Come hang out and smell the vinegar with me for a little while.
I fixed up my SC-3000’s cartridge slot almost a year ago, but I haven’t been using the computer. Why not? Because the keyboard is super unusable. It’s time to fix it now, though, because I just paid a king’s ransom for a copy of Flicky.
Without a working keyboard, the CoCo that I’ve been working on over the past few months might as well be a fancy desk ornament. When I took a look at the keyboard last time, the membrane had some pretty serious damage to its carbon conductive traces. Before spending money to replace the keyboard, I’m first going to try and fix those traces with the conductive paint I already paid for.
Sometime last summer, I spotted a local classifieds listing where someone was selling a “Tandy laptop.” After some interrogation, I determined that it was probably a Model 102. Another Kyocera sibling to join my NEC PC-8300?
When I first set up the PC-6001, I had to bring it back to life by replacing the shorted tantalum capacitors on the motherboard’s power rails. It’s such a great little machine! After some more testing, however, it became obvious that I was getting no sound out of the poor little thing.
Now that I know that the computer wasn’t horribly killed by my recap job and repair of all those broken traces in the ADB input system, let’s take a brief moment to recap that original Astec power supply from the “bad” LC. And fix the video!
While I was working on the bad ADB Mac LC, I tested it by using the “good” power supply from my childhood Mac LC. How good was that “good” power supply, though? Well, it smelled a little fishy.
When I first fixed the PC-6001, there were a few sticky keys on the keyboard. “H,” Left Shift, and - most importantly - Return were all bad to a certain extent. I could limp along with Ctrl-M for a little while to replace Return, but it was pretty awkward. How hard can it be to clean the keyboard?
When I got the CoCo up and running in the previous entry, I noticed that the keyboard wasn’t working particularly well. I found myself with some spare time to dismantle the keyboard, and unfortunately it has not yet been fixed. That doesn’t mean we can’t still learn a thing or two.
My first real computer was a Macintosh LC. They’re not held in especially high esteem, and they haven’t been redeemed by history, either. It’s not hard to see why: a pitifully low RAM limit (10MB) introduced alongside a more RAM-hungry System 7, generally poor performance across the board, and cheap components. I still have mine, but this isn’t it.
The internet is both really good and really, really bad for my hobby. On the one hand, it lets me buy cheap broken computers and shows me how other people fix them. On the other hand, sometimes people offer me machines and then I take them.
I finally got a keyboard for my PC-8801MH (I was on the verge of making one myself), and had to settle for a very dirty one as prices are just a hair shy of ridiculous. Even though I was primed by the pictures, I was shocked by just how disgusting the keyboard for the MH was when it arrived.
My PC-6001 came cheap because it was untested (and it did end up needing capacitor replacement), but the PC-6001mkII seems like it has always changed hands for a lot of money in Japanese collector circles, at least for as long as I’ve been paying attention to the prices. When I landed one for a great deal, I figured that there must be something wrong with it.
I’ve had the PC-8801MH for awhile, but haven’t even bothered to get it open. It was only this morning, when I looked over my pickle jar full of removed clock batteries, that I realized I probably hadn’t removed the clock battery from it - and hadn’t done the SR either. No time like the present!
Apparently, trying to get old computers is a lot like waiting for a bus. You spend months looking at the internet for Tandys, buy a bad one, and then two more nice ones come as soon as you get on. Maybe it’s not entirely like a bus, because that metaphor assumes I can get on all three at the same time. Also this one has a 286, so it’s like a really fast bus.
Clearly, I haven’t suffered enough pain from the Tandy 1000SX, so I made a choice to re-enlist. This time, it’s a completely untested 1000EX that I found as part of an auction.
We fixed the 1000SX’s power supply, and tested the motherboard for shorts. There’s nothing left to do but put the computer back together again and see if it works. And take it apart again. And to wish I had a fully-operational chip fab and precision schematics of every custom IC. Yeah, this one is gonna take a little more time.
I was disappointed to find out that my “not working” Sega SC-3000 was in fact not working. However, I had a hunch that it was a common flaw: cold solder joints on the cartridge slot. It also has a more subtle flaw: it smells kind of bad.
Sure, I’ve got NEC PC-88s, I’ve got NEC PC-98s, but didn’t NEC make anything that was a little friendlier to the home user? By now, you should know better than to doubt our friends at the Electric Company. The NEC PC-6001 has a thriving homebrew scene around it in Japan to this very day, and is still fondly remembered. Let’s rip one open and stuff it with hot molten lead.
When we last encountered the Tandy 1000SX, it decided to bravely blow itself up rather than face us in battle. With a lot of elbow grease and a little bit of solder-slinging, this testament to 80s shopping-mall computing will live again.
I removed the clock battery from my X68000 ACE, sped up my PC-98’s video, and got a keyboard for my PC-8801MH. Come enjoy this bite-sized collection of what’s going on with my machines.
Last time on the Tandy 1000SX show, I blew a hole in a power-supply capacitor without even getting the machine to boot. Talk about ungrateful! At least it gives me an excuse to buy more tools.
I picked up a Tandy 1000SX recently. My plan is to use it for experimenting with Tandy graphics and sound, and maybe even port a few hobbyist games to the platform. As per usual with my pick-ups, this one needs a little bit of work before it can be usable.
Another postie-threatening crate arrived on my porch this week. There’s a lot of projects in this one; I’m not even sure a single one is “usable” as-is. This one sort of got away from me, but those are the fun kind!
When I was much younger, one of the first portable computers I was exposed to was a Tandy TRS-80 Model 100. It was a surprisingly useful 80s portable machine. A real mechanical keyboard, modem capability, real ports, an okay screen, 20 hours of battery life on a set of AAs: it had everything. As a result, they were really popular with journalists (upload your story from a payphone!), scientists (take readings of your instruments at the site!), and industrial use (what’s wrong with this plane?)
Some more mini updates for things that weren’t big enough to merit a full update on their own. In this entry, we’ll finally get A-Train III running on my PC98, fix an Atari ST keyboard, and ship new hardware for a whole new brand of Japanese 8-bit computer.
When I first got the HB-101, its combination of small RAM and lack of any way to get software on it was a problem, sure. There was a bigger problem waiting, though: the grim spectre of an inconsistent keyboard.
In my previous entry, I found out that my old IBM PC “DOS” floppy adapter was not sufficient when trying to read from two drives at once. Somehow, they confused the floppy controller enough that nothing could be read from the second drive.
A few years ago, my friend Grant completed a refresh of one of his Model M keyboards (I know, right?) Here’s his writeup on the process.
I popped open my “good” Atari ST today. As you might remember, I have two 1040STFs: a very battered one I got from a flea market, and a nice-condition one that was owned by a guy who really cared about it, but had passed away. The only thing that was really wrong with this machine is that the mouse didn’t work.
I got another couple of Gotek floppy emulators from China, and now the SR has dual floppy drives. Unfortunately, I can’t use them both at the same time.
I’ve been wanting to get back to the SR for quite some time. I figured the Gotek adapter PCB and the HxC-flashed Gotek would be a direct drop-in to the new machine, and I was right.
Japanese Santa dropped by my house earlier this week and left behind a back-shredding 40lb box of microcomputer goodness. Let’s investigate.
I’ve been up to a bunch of little projects while waiting on parts and time for the big jobs, so here is another mini-update on three of those projects.
After a respin of the PC88 colour video board, the PC8801mkII now has excellent digital colour video out.
I’ve had my Apple IIe for a few months now, and it’s been great. One of the things that’s kept it from getting more use has been the spotty “I” key, which the seller warned me about.
Just as I was beginning to lose hope that the hard drive I had ordered back in August from Yahoo Auctions Japan would ever arrive, my doorbell rang. Inside a beat-up but functional Suruga-ya box sat the hard drive, done with its international journey.
Now that the PC98 can load software off of a USB stick instead of floppies, I decided to explore the software catalogue a bit.
I’ve been using the monochrome video cable on my PC88 ever since I built it. Colour video was a little more complicated, so I ended up designing a bunch of adapters to try and get it to work. I’m happy to announce that one of those adapters has finally worked!
Now that the PC98 can load a game off a flash drive, there’s a lot more parts of it I can test. Today, I spent a few minutes putting together a new revision of the floppy board and inspecting the computer.
After I designed the first version of my PC88 floppy board, I thought it would be fun to put one together for the PC98 as well. Why do I need an adapter for a computer that already has 3.5” floppy drives? The PC9821AP2 I own has a 26-pin floppy drive connector, like a mid-90s laptop, and most standard IBM PC style floppy drives have 34.
In the last entry, I found myself with a working adapter board to allow a 3.5” floppy drive (like a Gotek) to work with the NEC PC8801mkII. This liberated me from having to source, organize and maintain 5.25” floppy disks, and opens a large library of software for this computer without having to hunt through the used market. However, like all good things, there were a lot of bugs with the old adapter.
I wanted to get a Gotek working on my PC88, and after seeing that there were a lot of Japanese hobbyists who had managed to get an HxC floppy emulator working, decided it must be possible - even if not simple.
Many years ago, I grabbed an SGI Octane off eBay from a junk dealer. They didn’t pack it well, so the machine arrived beat up and stuffed full of styrofoam fragments from the packing material it had shredded on the way. After a few attempts to lug the machine around in the small condo I had at the time, I gave up and just let it slowly be re-absorbed into the pile of non-working computers.
I delved into the depths of my trusty Showa-era NEC to remove its leaking (leaked?) battery. Here’s what I found.
Going to try a new format for this entry; there are some small updates to keep a record of, but nothing deserving of a full entry on their own.
In the last entry, we left our intrepid hero with no video out. After a quick consultation of the Japanese internet, and a not-so-quick cable soldering job later, we now have black and white video and can use N88 BASIC (at least in theory).
While the PC9821 has horsepower and 90s clone styling for days, the real reason I spent all this effort and money was to get personal with the PC8801 platform. This humble little NEC home computer platform launched an indie game development revolution - well, or at least it did after this one was made. In fact, this 8801mkII, having been released immediately before the gaming-friendly 8801mkIISR, is only really useful to someone super weird who wants to learn about its guts on the cheap. I don’t know anyone like that around here, so I might as well do it. You’re welcome, future historians.
I only had a short amount of time to play with the computer today, but thanks to a very knowledgable friend, I got a known-good DOS 6.2 image with some disk utilities written to a floppy and booted.
Months ago, I won a PC8801mkII and a PC9821AP2/U8W off Yahoo Auctions. They arrived, but life got busy, and so the blog hasn’t been updated in quite some time. What better way to bring it back than a deep-dive into a computer whose language I literally do not speak or understand in even the slightest way?
Fresh off the success of the trace-repaired Genesis, I decided that I was an electronics god and could fix anything. That’s why I ordered this untested Mac SE from a place in Texas, where it was listed as being good to make a movie prop out of.
The SparcStation 1+ is still pulling its weird “Illegal Instruction” error, but at least now we know the keyboard works.
The slow accumulation of an entire collection of vintage Sun hardware continues, with the 1+ now being able to show video. The question is, what else will it take to boot?
The Mac TV is a machine that I’ve had for awhile. It’s a much better TV than a computer (the board is unusually limited, even for a Performa, and has almost no possible upgrades beyond what the computer already has), so it has been in storage for quite some time.
The replacement keys for my battered C64 arrived from Retroleum. It took a bit longer than I expected, but then again the postage was ridiculously cheap and it wasn’t like I was biting my nails waiting to play with the C64 I’ve had on the pile for a few weeks now. I’ll definitely be back to get more parts from them.
I’ve decided to start working on the “bad” Atari ST, with a non-functional keyboard and floppy drive, before I tear into the “good” 1040ST I just picked up.
Today was a good step forward. I finally got the case back onto the Amiga 2500, but there are still a lot of tasks left until the machine is really “ready” to be tucked away on my desk.
Now that work space is once again at a premium in my workshop, I find myself having to reassemble the diaspora of parts that were removed from my Amiga 2500 when it was dismantled to replace the 68000 socket.
Many years ago, I got ahold of an Atari 1040STF for really cheap. However, I didn’t have any monitor to use it with, so it has sat in storage for quite some time.
In a previous installment of the SparcStation 1+ saga, I got the machine to present a serial console to one of my other old computers, but couldn’t get any video out of the video card or boot to an actual operating system.
A power supply arrived from Ray Carlsen, and it works great. I spent the time while I was waiting by soldering a really bad video cable. I only managed to melt one DIN plug in the process!
If all goes well, I will soon be the owner of an NEC PC-8801mkII “Model 30.” The platform is famous in Japan, as later models of the PC88 featured a ton of independent games, including many from developers who would go on to create games that were popular worldwide (Thexder, Snatcher and Ys all got their start on this platform). It also has a lot of trash, but neither of these things are interesting to me right now. I’d be happier just getting the computer to work (not least, because as a non-SR mkII, there are very few games I can enjoy on it anyway).
Things are starting to get hectic again with real life, but there was still some time recently to work on the Amiga 2500. My objective was simple: get the machine back together into a working box again so it is no longer spread all over my workbench.
When I first got my Amiga 500, it wouldn’t boot. Suspecting something was wrong with the A501 512K memory expansion, I pulled the card, at which point it did boot. It didn’t take me long to realize that battery corrosion had killed it.
My streak of actually trying computers that are in my pile continues with this SparcStation 1+. While it has been a very loyal and very handsome monitor/keyboard stand for the last few years, it would probably be more interesting as a functioning computer.
I picked up a Commodore 64 off the local classifieds. It came with a 1541 floppy drive, a bag full of blank floppies and tapes, the C64 itself, the infamous black finned power supplies that kill C64s, a Rixon modem, and a Nortel multi-line keyset from the 90s.
The keyboard I got with my Amiga 2500 had:
- A broken right alt key,
- A spotty (at best) return key,
- And a numpad enter key that wouldn’t stay up, but did work,
I recently flashed an eBay Gotek floppy emulator for use in my Amiga 2500 with the FlashFloppy firmware (based on the phenomenal work of HxC).
I just got my A2500’s badly corroded CPU socket replaced with the help of my buddy and his employer’s substantial rework gear.
Many years ago, I ordered a surprisingly cheap Power Macintosh 9500/132 off eBay. When it arrived, the box was completely obliterated, with a hole in the middle that looked suspiciously like a forklift tine. Naturally, the Spindler plastics were nothing but dust. The seller sent me a replacement machine, and life went on, at least until I had to clean out that room and found the box of broken parts.
Threw a few more hours at the A2000 today, cleaning up here and there. I popped out the 68000, cleaned up the pins, and checked the socket. The socket wipers are immaculate, not a speck of corrosion or acid on them (I checked with a magnifying glass). The pins for the socket on the underside of the board are still nice and shiny, so I’m willing to say the socket is alright.
I’ve had this Amiga 2000 for several years, but it was only recently that I put in the effort to fix it. The big problem with these machines long-term is that the Varta clock batteries explode and corrode all the traces and sockets. Mine has a leaky battery for sure, so I hope I can save it.
A couple years ago, I traded some car parts to a friend for his dad’s old Amiga A3000 and A2500. I knew that clock batteries were going to be a threat on both of those, so I nobly waited a year to take apart and desolder the battery from the A3000. That was back in 2014.