Macintosh SE - Trash to Treasure

I recently spent some time restoring a Macintosh SE.  I got this project after someone had stalled out on it, and the machine came to me "complete" but disassembled in a cardboard box...

There was a note from the previous owner that stated "works, needs caps.  Bong, but with thin vertical line on screen", so I skipped troubleshooting and started in with the cleaning.  The machine was filthy, not as bad as the "barn find" Apple II+, but dirty enough that it would have been disgusting to work on without some major cleaning.  I took all the metal parts of the chassis off from the plastic parts and washed everything that would fit in the dishwasher, including the Logic Board.  I haven't ever tried dishwashing the analog or power supply boards as I think bad things might happen to the transformers.  As would be expected the parts came out looking much better.  As a side note after a particularly nasty job like this I run an additional cycle on the dishwasher with it empty to make sure all the "computer water" is flushed down the drain before we put stuff that we eat off back into the dishwasher again.

I manually cleaned the CRT and the analog board with paper towel toothbrushes and lots of IPA, avoiding the deflection coils which I clean using compressed air.  I reflowed the flyback connections on the Analog Board and many of the other joints on the board as well, and repaired a few broken items (loose molex connector, problems with the fan).

During this repair, I had the luxury of having another SE machine at hand as I was recapping it for a friend.  This machine needed only to have the Logic Board recapped and it was in much better condition than my machine and so I was able to swap known good parts onto my machine.  I determined that the Tube itself was still good and that my Logic board was working as expected, so it was good to eliminate at least a few components from the troubleshooting.  But the Power Supply / Analog Board combo was not working.

The next item on the list to address was the Power Supply.  I measured the supply, and the +12 Volt rails were at about 9 Volts, which I guess is typical for these when they need a recap.  I did the recap, but as I was doing it, I noticed dark brown marks (burns?) on the Power Supply circuit board.  After the Recap, the voltages on the Power Supply didn't come back.  I checked and rechecked capacitor orientation and other things, but decided that with the burn marks, my confidence would not be high in any repairs that I could carry out, so I decided to replace the supply with a modern supply that would fit inside the housing.  In hindsight, I should have gone out in the forums to ask but I did check in afterwords and discovered some interesting insights.  With my cheaper, but possibly sub-optimal Power Supply replacement in place, I was ready to pivot back to some testing.  I connected up all my parts and on power up, observed this screen...

The white line seems to indicate that the Horizontal Deflection isn't working correctly.  This of course is on the Analog Board, so I decided it was time to recap that.  I made an attempt to find a capacitor list for the Analog Board online, but I was not able to find one and had to make my own.  I had trouble finding a couple of the specific values and didn't realize that one of the critical ones (C15) is a Non-Polarized type Electrolytic Capacitor, so that put the project on hold for a week waiting for two different batches of parts to arrive from Digikey.  Once I got the Analog Board recapped and put the system back together, I was greeted with this very gratifying sight...

The machine was coming back to life!

The next order of business was to work on the Floppy Disk drive.  At the beginning I'd done a very quick service on this drive, but the mechanism was still not moving smoothly on eject, so I went back and watched this video from JDW and followed the steps more closely.  I did end up having to borrow the eject motor from another drive to get this one working, but I'll order some of those gears that JDW mentions to get this other drive back in order.

So, now the Mac SE has a floppy to boot from. I also installed an internal storage device, plugged in a SCSI Zip Drive on the back and started copying files into the machine.  All was not well, thought.  I didn't know it, but I don't think I'd found the root cause of the burn marks on the Analog Board and the reason for the overheating in the original power supply.  The screen went black during a file copy operation, and I discovered afterward that Transistor Q2, part of the Horizontal Deflection had gotten very, very hot.  I tried replacing this transistor, but alas, that was not the root cause and I was quite frustrated and put the project aside for a while.

I mentioned the struggle I was having to a friend in the retro community and he offered an SE analog board that had a damaged POT on it.  I jumped at the chance to be done with the old Analog board, swapped that, and the SE was back to life again.  Long may it live...

So, in hindsight, not the smoothest repair I've ever completed!  The Power Supply recap was a failure, but I learned that multiple modern alternatives exist.  The Analog board recap was also a failure as I was not able to discover the root cause of the burn marks and cascading failures, but sometimes we learn more from failures than we do from easy wins.

This is the first of the SE generation of Mac that I have (I have several of the previous original generation, and one Classic II), I upgraded the SE to the maximum 4 MB RAM and put a 100MB HDD in it.  I'm glad to have one of these in the fleet and it will be both fun to play with as well as a helpful troubleshooting tool should I come across machines of this type that need service in the future.

Nice Northgate!

As I've continued to learn about Minnesota's computer history and the history of the PC compatibles, I've learned that Minnesota seems to have had more than our fair share of successful PC clone builders.  Perhaps this was a lingering effect of Minnesota's strength in the early days of computing with Remington Rand and several of the the mainframe companies located in Minnesota (IBM and the Seven Dwarves).   I know of at least one individual who left an engineering job at a mainframe company in order to run a business building PC clones.

Many of these companies didn't have the market size to design their own boards, and so they would purchase and build systems using boards from many different vendors in Taiwan, but there were a few companies that either started early enough or had a large enough market share to do their own motherboard designs.  There were a couple of local companies that Minnesotans might recognize, ZEOS and Northgate Computer Systems.  Both advertised nationwide, and so had some broader recognition.  It seems that both struggled with financial trouble in the mid 90s, Northgate going through a bankruptcy and Zeos a buyout.

I've been interested in Northgate since I've had one of their keyboards for a while.  I was recently offered one by a collector in St. Paul who is looking to downsize.  The machine was untested, but I was able to look inside and ensure that there wasn't battery damage.

When I got the machine home I unplugged the mainboard and checked the Power Supply voltages.  Everything checked out, so I plugged it back in and it booted.  Of course the clock battery was dead, but I was able to set the BIOS parameters and boot off a floppy.  I was not able to figure out how to set the BIOS to recognize the hard drive but after some time I realized that the Specifications sticker on the back of the machine listed the Hard Drive's BIOS type on it.  When I entered that data in the BIOS the drive was recognized right away and the machine booted to DOS 6.22.  There was a Drive Overlay installed on the HDD to get it to recognize the additional space on the drive, it has a 450 MB drive that appears to be working just fine.

One of the next challenges with this machine was determining which Northgate system it was.  There is not a ton of information available online about these systems, but I found this list on Vogons.  By googling images, I was able to determine that this was a Northgate Slimline 320 (A 386 @ 20 MHz with a date of 1991 on it).  Knowing the model I was able to find these jumper settings and specifications.  It turns out that this unit has already been maxed out at 8MB RAM.

After this, I needed to decide what to do with the machine. It has a total of 3 16 Bit ISA expansion slots, and two 8 Bit slots on the back.  It had a modem which I removed, and replaced that with a generic sound card.  I have a not quite period correct, but significantly cheaper Sound Blaster Vibra 16 on order for this machine.  I also used the slightly newer 3COM 3C509B 10MB Ethernet card.

For storage, I tried directly connecting a Compact Flash card to the IDE Bus on this machine, but I was not able to get the BIOS to recognize the newer cards that I had (2GB and 4GB Sandisk and 1 other brand).  I wouldn't have minded if I could only get those cards working with 250 or 500 MB partition, but nothing was working so I installed a Lo-Tech XT-IDE card that I already had on hand from another build that I changed.  This boots the machine just fine.

Once I got DOS and some of my standard Games and Utilities moved over to the Compact Flash drive, I tried to install Windows 3.1 on this machine.  The machine has Integrated Graphics, and when that is enabled, a boot message indicates that the video card has 256K RAM onboard, which is enough RAM for 640x480 with 8 bit color.  However, I could not get this to work with Windows 3.1, either on the original Hard Drive or on the CF based storage.  Windows 3.1 locks up after the splash screen.  This makes me wonder if the reason this machine was taken out of service back in the day was because of a failing video controller on the motherboard.  Anyway using the board Jumpers I was able to disable the onboard VGA, and test several other 16-bit ISA Video Cards that I have.  I decided to use the most "period correct" VGA card I had.  This came from another 386 parts machine, and it also has only 256K RAM on it.  This works great in Windows 3.1, but of course has no acceleration, which is just fine for this machine.

So that about wraps it up for this machine.  I'm really happy to have a nice clean Northgate Computer in the collection that pairs nicely with the Northgate Keyboard that I've previously blogged about.

Please let me know if you have any memories of using Northgate Systems back in the day, or any tips about where to find additional technical information about the Slimline systems online?

Epson Equity LT - An XT Class Laptop - Flash Storage Solution

As readers of my blog will know, I have a bit of a soft spot for XT class machines with the Intel 8088 processor and similar processors.  One of my first retro computers was the Compaq Portable from 1983.  My friends at Free Geek know this about me, and so I'll occasionally get a machine from them that needs help.  I recently got a Toshiba 3100 machine from them that matched up well with some machines that I helped my friend John with, a couple of those Toshiba machines appeared in this video on his channel.

Anyway, the latest acquisition was an Epson Equity LT machine from 1988.  This make it a "later" XT machine, and instead of a gas plasma display, this has an early monochrome TFT display.

I tried quite hard to get a hard drive going in this machine.  After reading this article about the somewhat proprietary XT Laptop based Hard Drive interface, I even went as far as pulling the Hard Disk out of the Toshiba 3100 which has a bad screen and trying to transplant it into the Epson Equity LT, but I was not able to make this work.  The Epson does spin up the disk, so it worked better than the totally dead drive that I started with, but I was not able to get past a drive error.  I looked for information about a low-level formatting the drive, but that is either not possible or just not documented.

However, I have found what I think may be a better solution in the long run because it's a more generic solution that will apply to other XT class laptops or luggables as well.  I installed a GoTek floppy drive emulator with the Flash Floppy firmware into this machine.  Once the Hard Drive is removed, it's easy to move the original "A" drive over to the left side of the machine and use it as the "B" drive, installing the GoTek as the "A" drive.  Using another computer, I setup a new low-profile USB Flash Drive with 720K Disk Images on it.  One of these disk images has DOS 5.0 and another has DOS 3.3.  Most of the disk images on the floppy have games on them.  These are early DOS games that run in CGA graphics mode, like Alley Cat, Burger Time, Avoid the Noid, and titles like this.  I also created a boot message on the DOS 5 (default) boot drive that lists out which programs are stored on which floppy drive so you don't need a list of Floppy Numbers if you are using a basic GoTek like this one...

I'll include a link to the contents of the USB Flash Drive that I've uploaded to the Internet Archive.

A couple of other "longevity" upgrades included installing a new 3.6 Volt Lithium battery for the realtime clock and permanently removing the main battery that was installed in the machine.  This machine will just be used for demonstrations with power and it's one less thing to worry about.  As an added bonus with the battery, hard drive, and drive controller removed, the machine is alot lighter!

With the low profile USB drive installed, I plan to leave this machine setup and ready to go.  Now I just need to find an old laptop bag that will work for this monster!

A New Retro Computing Forum?

As readers of my bLog will know, I'm a big fan of the forums, and one of my favorite things about Retro Computing is the help that the members of the community offer to one another.

I was recently invited to join the "Tinker Different" forum which has just formed.  Several people I know and a couple of the YouTube personalities that I follow are on board with this project.  The first question in my mind when I heard about a new forum was, why another forum when there are already several to choose from.  The reasoning is explained in this video, which I found quite compelling.

I'm excited about the project and I look forward to contributing.  I hope to see you on Tinker Different!

SuperCard Pro - For Disk Imaging and Drive Repair

Disk Imaging

One of my interests in the Retro Computing hobby has been software preservation.  Trying to recover data off some of my wife's old floppy disks from her college days sent me down a path that's gotten me to the point where I own several different Macs and PCs from the 90s that I use as "Bridge Machines" to get data moved off old floppies onto modern hardware.

I'm also interested in a range of different systems and in having the ability to make and restore disks of any format.  I became aware of the Kryoflux disk imaging system when reading on Sonic Purity's blog on this article that I've referred to in several bLog articles before.  I didn't pursue the Kryoflux because this solution was expensive and because I didn't understand floppy disk technology well enough to be comfortable with flux imaging.   Thankfully this knowledge gap can be easily addressed by a great deal of information on the Web, and since then I have put more time into researching this topic.

One of the few benefits of the Pandemic has been that all the Vintage Computer Festivals have been online.  I learned about Jim Drew's SuperCard Pro from watching Craig Ernster's presentation. at VCF Midwest 2020.  This device is significantly less expensive than Kryoflux.  I didn't buy one right away, but when I got my first CP/M machine and didn't know how, or even if I'd be able to make floppy disk copies with the machine I put one on order.

I've paired the SuperCard Pro with the Asus laptop I use as my retro computer engineering PC and set up a couple of floppy drives, both a TEAC 5 1/4" DD drive as well as a newer 3 1/2" 1.44MB floppy drive.  I have stored these items together so it doesn't take long to have the disk imaging solution up and running on the bench...

So far, I have imaged and restored boot disks for my Compaq Portable (360K Floppy with DOS 3.3), and that worked well using a preset in the software.

Also I've imaged and restored boot disks for my Megatel Quark 100 CP/M computer, again, using a CP/M preset in the software.

Drive Repair

The Super Card Pro has also been helpful for drive diagnostics and repair.  It has a separate screen  for Drive / Disk Utilities.  This allows you to control the drive motor and also the track steppers that move the heads back and forth.  As you can see in some of Adrian Black's videos, having separate control over these two drive functions can help when lubricating and troubleshooting drives that haven't run for a long time.  Using these features of SCP, I've been able to troubleshoot these issues:

Drive Motor Speed Adjustment

Index Sensor Good / Bad

Track Stepper Motor Position

Track Zero Sensor Good / Bad (the Disk Media Test will fail if the Track Zero sensor is not working)

When comparing the functions of the Super Card Pro with IMD, I believe that IMD could also be used to diagnose all of these scenarios, but I find the SCP interface a bit easier to navigate.  One gap with SCP, I have not been able to adjust drive alignment with this tool.  I think the IMD program is the only (easy, non oscilloscope) way to do that.

My latest drive repair was getting a pair of Magnetic Peripherals Full Height DS/DD Drives back up and running for my IBM 5150.  Although these drives are now fully functional the alignment of these drives doesn't match up with the other 360K drives that I own.  Drive alignment is still outside of my comfort zone, but I'm hoping to learn more about that soon so I can get the various drives I own back lined up with one another.

My (Current) Favorite Retro Computers

It's been a while since I took a picture of my basement shelf where I store my most frequently used Retro / Vintage Computers.  The ones that are out and get used are my de facto "favorite" retro computers, and there's been a fair amount of change on the wire rack since my last update.  I thought I'd outline which computers are out, and why:

From Top to Bottom, Left to Right, on the file cabinet is the NeXTstation Mono Slab (1990).  This is one of my newer acquisitions from Vintage Computer Festival Midwest 2021.  I've still got alot to learn about this machine, and I also have some hardware on order for the machine so I'll be leaving it out for a while.

Next is an original Compaq Portable I (1983).  This was a "project" machine from Free Geek Twin Cities and my first XT class machine.  As one of my first Retro computer "rescues", I really enjoyed the process of getting it working again.  I also really like the design of it and I've used it for disk imaging and a few games that look really cool on the Green Screen. (it has a really long persistence phosphor.)

Next to that in the top right corner is the original non-backlit Macintosh Portable (1989).  Yes, the screen is on, this just shows how you need the lighting just right to see the screen.  I'm fortunate to have one of these that is working as many of them have problems.  Mine has a few dead lines on the screen, but I'll just keep enjoying this while I can. It's probably just a matter of time till the screen dies.  This computer is out on display because I enjoy the fact that it's so different than the laptops of today, a design idea that failed.

On the middle row at the left we have an un-enhanced Apple IIe computer (1983).  I was able to buy this computer monitor and disk drive as a set from a retired school teacher who had bought it new.  It needed quite a bit of repair but since completing those repairs it's been super reliable and super fun.  Total Replay anyone?

To the right of that I have a Power Macintosh 8600 / 200 (1997).  This is a "Bridge Machine" that I have blogged about before.  The main reason this machine is still on the wire rack is utility.  It's easy for me to move files off and on this machine from my modern machine and I have three SD cards setup for Mac OS 7.5.5, 8.6, and 9.1, so it can run the first version that is supported by the hardware all the way up to the last version.  The latest upgrades for this machine include a new Logic board and Processor Card (Still 200 MHz), additional RAM, (288 MB Total), and an ATI Rage 129 video card from 1999.  This machine is running better than it's ever run before.

On the bottom row at the left we have a Macintosh 512K (1984).  Like so many of these machines it started out life as an original Mac 128K but got upgraded fairly early in life.  It has been continuously upgraded to keep it going since then.  It's possible that the only original thing on it is the chassis but I feel very fortunate to have this machine and I enjoy playing some of the classic games and booting Mac OS 1.  It's an absolutely iconic design, and the only system in the display that boots and runs exclusively from floppies.

Last but not least on the wire rack in the bottom right corner is my latest PC Build.  This is a PCI based 486 DX2-80 (1995).  I built this with parts and pieces from a friend and other items I had around.  This is both a Retro Gaming rig with a Sound Blaster in it and a Disk Imaging machine with a 5 1/4" 360 K Floppy drive.  It works great so far, but I just built it, so I'll need to keep it out where I can power it up and keep using it to work out any kinks in the build.

Honorable mention, I also have a Tandy Model 102 (1983) slab top machine that I keep out on display in a different part of my office.  I really appreciate the unique design of this machine.  Another form factor that really didn't last into the modern computer era.  I've recently got a flash based storage solution for this machine, so I'm looking forward to digging in more on this machine, including loading some of the BASIC games onto the machine.

I have more machines but they are all stored in a much less convenient location.  Some of those machines are plugged in and can be run, too, but they get significantly less use than these ones that are out.

My Favorite Find at VCF Midwest 2021

My best find at VCF Midwest this year was a NeXTStation Mono Slab with matching Monitor, Keyboard and mouse.  I understand that out of the three different variations of the NeXT computers, this one is the least desirable, but that also makes it the most affordable, so I'm quite pleased with the purchase.  I've heard the claim that there may have only been about 50,000 NeXT computers made in total, so I feel fortunate to be the NeXT owner of this NeXT.

The previous owner has handed off some media to me, and he's also shipping manuals.  I'm pretty excited about having those original materials.  I've never been hands on with the NeXT before, but I remember reading about the company back in the day when Steve Jobs returned to Apple and Mac OS X was in its infancy, those were exciting times in computer history.

This particular computer was made in 1991 and has the base Motorola 68040 processor at 25 Mhz, maxed out at 128MB RAM, and has an upgraded HDD, a Connor 1 GB SCSI drive.  I'm a bit worried about the longevity of this SCSI drive, I think it's from 1995, but it isn't making bad sounds, and this systems has only a base install on it without much else, so I'm not in a big rush to get a SCSI2SD installed.

Macintosh IIsi Power Supply Woes

In the Fall of 2018 I was able to acquire a Macintosh IIsi machine from Facebook Marketplace.  This came out of a smokers home and I've been unable to get rid of its smell, so it's never been one of my favorites.  I've taken the machine completely apart, washed and retrobrighted the plastics and rinsed the circuit boards with Alcohol, this did help some with the smell.  Here's the current state of this machine...

When I purchased the machine, it wasn't running well so I recapped both the logic board and the power supply using the recapping guides from Recap-a-Mac.  I didn't do this well; I'll come back to some lessons learned about recapping.

What helped most with the smell was the tip I received that storing the machine with dryer sheets would help to absorb bad odors.  Since this was a machine that I didn't need to keep setup I bagged up the machine and monitor in a large garbage bag with a bunch of dryer sheets and stored it for 6 months.  This helped alot with the smell so I'll be doing this again as some odor remains.

I pulled this machine out a couple of weeks ago because it's the only machine in my collection that's capable of running Apple's Unix product,  A/UX.  I had been inspired by this video from Sean at Action Retro to try A/UX.  Unfortunately, my IIsi would not power on.  I started reading up about issues people were having with these machines and decided that it was most likely that I had not adequately cleaned the Power Supply circuit boards after the recap.  I tried alot more cleaning and I was able to get one cold start out of the old power supply.  After spending hours troubleshooting the old supply I decided to cut my losses and look for a replacement.  I'd been inspired by the idea of putting an off the shelf power supply inside of retro power supply enclosures by an attempted repair of my Tandy 1000 RL HD based on a post on Vogons.  I had saved information about a small, low cost Meanwell brand power supply that Jameco is reselling, this supply has the following specifications:

5 Volts at 5.5 Amps
+12 Volts at 2.5 Amps
-12 Volts at 0.5 Amps

The Sony Power supply inside the IIsi had the following ratings:

5 Volts at 6.8 Amps
+12 Volts at 0.8 Amps
-12 Volts at 0.3 Amps

So, the new supply is a bit short on current for 5 Volts, however if you look into the datasheet, if the other channels are running with less load, then the 5 Volt supply can peak at 7 Amps output.  I was hopeful that by taking the spinning Hard Disk out and replacing it with flash based storage I would lower the total power consumption of the computer to the point that this power supply would be adequate. (Spoiler alert, the power supply works just fine!)

Another important consideration is the physical size, I wanted the Power Supply to fit into the enclosure of the previous power supply so that the machine looks original from the outside.  Here's a picture of the finished product inside of the housing of the old supply...

One of the other challenges I faced with this project was the wiring on the old power supply.  I'd cut the old wiring harness off the power supply and tried re-soldering the old wires too the new power supply, but the old wiring is stranded wire that is very difficult to solder on.  Eventually I gave up and used Wago spring clamp type terminals to connect the old wiring harness to the new wires.

I connected the obvious wiring:

Red to 5 Volts
Black to Ground
Green to -12 Volts
Orange to +12 Volts

This left the Yellow and White wires unconnected.  Through trial and error, I discovered that the Yellow wire needs to be connected to +5 Volts in order for the IIsi logic board to power up.  I knew from reading ahead of time that I'd be sacrificing the soft power feature.  When this Mac is plugged into power, it is on all the time.  I modified the power pass through on the back so that the monitor can still be plugged in on the back, it is no longer switched, it is also on all the time.  I also modified a standard IEC power cord to put a switch inline on the cord (using a lamp cord switch), this allows me to power the computer off without unplugging it.

I know this is a bit of a hack, but it is one that is within my skill level.  I was willing to make the sacrifice in order to regain confidence in having this machine work when I turn it on.  Even with the compromise.  I have not modified the outside of the computer and so in my opinion this is an upgrade, although I realize that not everyone in the retro community will agree with me.

Another item that had failed since I last used this machine was the original Apple 40MB SCSI drive, so I've replaced that internal drive with a BlueSCSI.  This works well and speeds up the machine a fair bit.

So, after all this hassle, I was reminded that this machine has only 17 MB RAM.  Although Apple A/UX 2.0 might run just fine, 3.0 is probably not a good idea till I install a RAM upgrade.  The other challenge to getting A/UX on this machine is I'll need to find a way to simulate an Apple Brand SCSI CD-ROM drive.  I believe that I'll be able to use SCSI2SD to do this, but I have more research to do.  For now, I'm just glad to have the machine back in running order and I'll enjoy running Mac OS 7.0.1 on it.

Do you have any nostalgia around the Macintosh IIsi, or any experiences with Apple A/UX?  If so, send me an email, or drop a message in the comments below.  Thanks!

Cheap, Fast Bootable IDE Solutions for Retro PCs and Macintosh

I've been working on a series of articles about the things I love about Retro Computing.  The keyboards in general were good, and some were shockingly good.  CRTs appeal to me.  I really enjoy the entire Floppy Disk experience, as that's what we used when I first learned about computers in grade school.  The older Double Density floppies actually tend to be quite long-lived when stored properly, I have 20 and 30 year old disks that still work as expected!

For me, Hard Drives fall into the "not worth the worry" category.  Flash based storage solutions are faster and they make better sense from a preservation point of view because they will keep the machine operating for a longer period of time into the future.  So, one of my ongoing goals has been to figure out what the cheapest method of providing flash based storage to these old machines is.  I'll use this article to catalog a list of solutions that I've tried.  I'm going to cover, total cost per unit (regardless of capacity), cost per GB, Speed, and other considerations.

I've used a couple of different options for IDE machines.  First is using a CF card in place of an IDE drive inside of PCs. For tower and desktop machines, I like to keep the drive accessible from the back, so I prefer these simple passive circuit boards on a Slot cover bracket.  The circuit boards cost about $10, and the price of the CF card is based on the size, w/ 4GB cards costing about $15 each on FleaBay on April 2021 (for used, Industrial rated, name brand cards).  This give a total installed cost of $25.  Depending on the Compact Flash card itself, these can be capable of quite fast transfer rates, with the proper CF card, your computer should be limited by the speed of the IDE interface in the machine.  Here's a picture of my 486 build showing the CF card bracket on the back...

For IDE based Laptops, these CF to 2.5" 44 pin IDE drive adapters cost just a bit more on Amazon, these were about $18 delivered putting the total cost for a 4GB drive solution at about $33.  Again speed is dependent on the CF card itself,  I have one of these in a PowerBook 3400c and that's worked well.

Here's a cheaper solution that I will mention with a caveat.  There is an SD to IDE solution sold on Amazon, but I have tried this solution in several different computers and it's hit or miss.  Sometimes they work and in some computers they just don't work at all.  The price is $16 plus the cost of an SD card.  As you will see in the detail they are quite slow, limited to 25 MB/s transfer rates. The limited compatibility and speed is a disappointment because as CF cards become less available and more expensive this could become the cheapest option on the list.  It's already close to the least expensive at $26 in 2021.

I recently learned about another option from Sean at Action Retro.  He's been recommending and using some low-cost mSATA to IDE drive adapters and lost cost mSATA SSDs from China that work well, are brand new, and have significantly greater storage than the options I've mentioned here.  Here's a link to a drive enclosure, I can't vouch for this seller yet, but there are many like this on Fleabay.  Here's a link too the SSD drive itself.  Note that you have to be careful to match the keying, physical length, and the communication standards for the drive and enclosure, as the enclosure will not work with PCIe based cards.  After I figured this out I was able to upgrade my Pismo with this...

The drive is the white plastic enclosure on the right, not very visually interesting, but this solution cost about $31 for both parts of a 64 GB drive so this is far and away the lowest cost per Gigabyte of the storage options and still in the middle of the pack for overall cost and at the top in terms of speed.  This will be my go-to for "bridge" systems that will see use for disk imaging or backups.

In summary, the CF card solutions still seems like the best solution for now for the older machines given the relatively high speed and lower price but for newer machines the mSATA SSDs will be my go-to solution.  Thanks again to Sean at Action Retro for highlighting this option on his YouTube channel!

Do you have any experience with Flash based storage solutions for older Macintosh or PC based machines?  What low-cost solutions would you add to this list?  Comment below, or feel free to send me an email.

Things That I Love About Retro Computers - Keyboards

For me, one of the distinctively enjoyable aspects of Retro Computing is the Keyboards.  I know I'm not the only one, with everyone from Clint from LGR to Perifractic from Retro Recipes devoting entire YouTube episodes to the topic of vintage computer keyboards.

I've become a bit of a "keyboard snob" over the last few years, ever since I found out about Unicomp keyboards.  The story of Unicomp's spinoff from Lexmark / IBM has been covered well elsewhere so I will not retell it here, but I learned how to type on an IBM Selectric keyboard so the buckling spring type keyswitch feels both familiar and nostalgic to me.  I've been using these keyboards for years and I have several of them.  The main drawback I have with these is reliability,  Of the three boards I've had over the last 10 years only the most recent purchase is still working well.  I have used these as daily drivers, but I'm sure I'm nowhere near the cycle time limit on the keyswitches, the faults tend to be with the other electronics on the boards.

I've also made another keyboard discovery that was a bit of a surprise to me.  The Apple keyboards that I remember from the last 10-15 years have been pretty unremarkable, but if you go back far enough in time their keyboards were remarkable.  My "Daily Driver" keyboard is an Apple Keyboard model M0116 made between 1987-1990.  It has Alps Salmon switches, (which you can hear here) and it's really fantastic.   This keyboard is connected from ADB to USB using the Wombat from Big Mess O' Wires.

The downside too the M0116 keyboard is the keyboard layout.  The cursor keys are not in the inverted T layout we've come to expect and the Caps Lock and Control keys are swapped.  It's difficult to remap these swapped keys because this keyboard has the two-position Caps Lock key.  Also, there are no Function keys on the keyboard.

The Apple Extended Keyboard from the time, model M0115 is a more familiar layout with the same keyswitches, but prices on these boards have become quite high, so although I'm hoping to find one at some point, I'm not holding my breathe.  In the meantime, I will continue to enjoy the M0116 as my daily driver.

Another truly great retro computer keyboard is the Northgate Key Omni Key 101.  This is a keyboard that was made for a company here in Minnesota, Northgate Computer Systems.  I believe this example dates from 1991.  I bought one because I was looking for a keyboard that was AT / XT switchable. bit ot turns out this keyboard has absolutely fabulous key feel with Alps white switches.  I've written a bLog article about restoring this keyboard, and I've since put this keyboard into service with a simple PS/2 to USB adapter as my daily driver.  I'll be keeping a lookout for these keyboards now that I know there's a resource for parts, Northgate Keyboard Repair.

What are your favorite Retro Computer Keyboards, and why?  Do you use a retro keyboard as your daily driver?  Let me know in the comments below.

PowerBook G3 Repair Marathon Report Out

Over the last weekend or so, I’ve been working on PowerBook G3s from the large lot of computers I’ve mentioned in a previous bLog article. This has been lots of fun, both a great learning experience about repairing this hardware, and after the repairs are complete an excellent opportunity to learn about using these systems, as I only used desktop Macintosh computers during this time period.

The largest number of systems that came in this lot were PowerBook G3s.  I have had this type of system on my short list for quite some time, but hadn’t got enough hands on experience with them to even know which one I’d like the best.

I started with the Wallstreet machines, the first of the G3 PowerBooks.  There were 10 of these systems...

It was quite a bit of work tearing them all down because they were in really rough shape, so a lot of them had to be separated from the top and bottom, and also I had to tear down and combine parts for one of the display panels.  Sometimes I had to combine parts from 3 or 4 different smashed systems to get back to one working machines, but like any challenge, it’s very gratifying to have gotten two working systems with Active Matrix screens...

These look pretty nice on the inside when they are open, but the display top covers are rough.  I'll be on the lookout for new ones.

I was also able to recover another two working Wallstreets with Passive Matrix screens...

It’s been interesting to install Mac OS on these machines (Mac OS 8.6), and see the differences between the Passive and Active Matrix screens.  I think the Passive Matrix screen on the 1400cs was superior to this G3 screen, but it may just be differences in the specific units that I have here (these backlights tend to shift colors after they get alot of hours on them.)

Moving ahead in time, there were 6 Lombard (Bronze Keyboard) G3s...

These were easier to work on, as they were in somewhat better shape.  There were only two display modules that had not been smashed, so I knew right away that I would only need to get two systems working, and here they are running side by side...

I installed Mac OS 9.1 on these after reading about a problem with the Sleep mode with earlier versions of the Mac OS.

Any last but certainly not least, the Pismos.  There were four Pismo machines...

These were in similar condition to the Lombards, much better than the Wallstreets.  But with only four machines, I was only hoping to get one "runner".  However, there were two functioning display modules in the lot, and so I was able to build two working machines, and here they are running side by side...

The display module on the right is significantly brighter and has better color than the one on the left, so I've swapped that display onto the machine that had Max Ram (1GB).  This was an almost unthinkable amount of RAM back in the day, and I've taken a page from Sean at Action Retro's book and ordered an IDE to SATA drive adapter to put some super fast flash storage in this machine.

But, to come back to which is my favorite, I do think the Wallstreets are pretty cool.  It was such an interesting and amazing time between 1998 and 2000 when the speed more than doubled.  I also have a soft spot for "last of" machines and the Pismo is the last portable with a SCSI port.  So I guess I still can't come back to which is my favorite.  I'll have to pick out the best one from each lot and spend more time trying to figure this out.

In the meantime, after repeating this process over and over again, I’ve developed a workflow for working with larger lots of machines like this.  I will share my experiences in case this could benefit others.  First, I'd read up about the model that I’m working with using both the official Apple Service Manuals and also looking through the iFixit tear downs.

Then, I’d go through and separate the display modules from the rest of the laptop, like this...

Once I'd identified one good screen and laptop pair, that could be used for troubleshooting through all the screens.

Once the screens were dispositioned, then I'd work on the bottom half.  If needed, several bottom units could be taken apart and combined together to get something that looked OK and was working.  

It’s useful during this process to understand just how little of the computer is required in order to get the Boot chime from a G3 Powerbook to check if progress is being made.  No display is required, no HDD is required and only minimal RAM, so you can test that the assembly is going OK without completely reassembling the computer.  The power board and sound card (if it is separate) are both required to get the Boot Chime.

I'll be using this system as I move into troubleshooting the Silver PowerBook G4s next.  The effort to recover these machines grows larger as the complexity (and number of fasteners) increases on the newer machines, so I am fortunate for the opportunity to start earlier in the PowerBook history and work towards the more recent machines.

PowerBook 3400c repair

Last weekend I worked on PowerBook 3400s from the large lot of computers I’ve mentioned in a previous bLog article. I’ve had one of these since last fall, I was fortunate to find it on Craigslist at a reasonable price, but that computer has been having display problems, the display gets brighter and dimmer at random.  I suspect that the backlight or inverter board  is failing so I was excited about getting some new screen components for this computer I already had.

There were three of these machines in the large lot of computers in April, and despite my initial skepticism I was able to get one running computer out of this lot.  This is a nice 3400c with the fastest 240 MHz processor.  I was super excited when I saw that one of these three machines was the 240 MHz machine, I’ve been interesting in the fastest machine in the line ever since watching Colin from This Does Not Compute’s episode about this machine.

There isn't much RAM in this machine, but since this is nicer than my Craigslist 3400c I’ll be moving the expansion RAM over too this machine and using this as my primary 3400c.  I have been using this machine as a Portable Bridge Machine for moving data around and making floppies since it has a lot of connectivity options, including a VST ZIP Drive for the expansion drive bay.

There is more hope for further repair on the Craigslist 3400c as well, since it’s likely that one or more of the backlight and inverter boards in the smashed screens are still working, but taking these display modules apart will be a tedious task, so that’s a project for another day.

PowerBook 1400s are Great!

I've been repairing my way through a huge pile of laptops I bought from my friend John @ Roadkill, Inc.  It's been alot of fun since I got to start in with the actual repairs.  I'm not just cleaning and organizing them anymore.

I've been moving up in age from oldest to youngest.  Last time, I blogged about the 5300s.  This next lot of computers I had was 1400 machines...

I brought 4 machines into this round of the project.  These, like the 5300s have been really great to work on.  I already have a 3400, a follow up machine to this machine, which I have worked on a bit.  These are from the pre iFixit era, there are not detailed tear-downs for these machines at that site, which I usually prefer over videos when I'm working a project like this, but having watched a few relevant YouTube videos, and with a bit of experience from the 3400, I started in.

I was able to get two machines running out of the four.  The first is a 1400cs with a passive matrix color screen...

This passive matrix screen is easier to use and has better viewing angles than many I've used.  It's still not great, but I think it's "best in class" for passive matrix.

By combining RAM modules from the various machines, I was able to bring this up to 52MB RAM.  It's IDE HDD was dead, so I replaced it with a larger drive from another machine.  As you can see, the speaker grill is missing, so I've got that on the wish list for later.

I purchased an HDI 30 Pin SCSI adapter on eBay so that I could use a ZIP drive with my old portable Macintosh computers.  It's fantastic to have access to Bootable SCSI Zip drives on everything from my PowerBook 145B up to the G3 PowerBooks that were the last to have SCSI Built in.  Taking a page from Adrian Black's book, I've setup a series of bootable ZIP disks with various versions of Mac OS on them...

I can take a non bootable system with a functioning HDD, boot off the Zip drive, format the HDD, and copy over a working system disk with very little effort.  Building this library has been a timesaver for this project and will be a great tool to have going forward.  This is especially important for the 1400s and earlier machines, because these laptops don't come with an Internal CD-ROM option.

But, back to the 1400s.  The second running system I got was a 1400c, with an Active Matrix screen...

This machine has the faster 133 Mhz processor and 56 MB RAM, the original HDD still works, so it's only a 750 MB drive, but more than enough for my purposes.

I put Mac OS 8.1 on both of these machines, and they run great.  They really are a significant step up from the 5300 in terms of quality, it was noticeable in doing the repairs.  They just look and feel alot better than the 5300, even after just a few hours of use doing Mac OS installs.  I'm quite pleased to have these in the collection and I plan to clean them up a bit more as they still have some of the scuffs and scratches on the outside of the case.

These are the first of the PowerBooks that I have which use the larger 9mm Barrel Jack Power Supply.  These 24V power supplies were used up through the Clamshell G3 iBooks, so these 1400 machines could be powered using the early Yo-Yo power adapters.  Although the 1400 originally shipped with a lower capacity Power Supply, the M4896 Power Supply is the correct color, and a bit more flexible since it provides 45 Watts.  I was able to get a couple of these from a friend of mine that volunteers at Free Geek Twin Cities, so I'm a bit closer to the goal of having one Power Supply for every working computer.  These are becoming more and more expensive on Fleabay, so I may have to resort to a hack like this.  Stay tuned, I've already started on the Wallstreet G3s, and after I get the Pismos up on the workbench then I'll have a better handle on how many power supplies I need to find.

Is the PowerBook 5300 the worst Macintosh Laptop of All Time?

 As I've mentioned in a previous post, I got a large number of laptops from a friend in April.  I've been slowly working through the stack, sorting, categorizing and organizing.

There are several types of PowerBooks that I've never seen or worked on before, including PowerBook 500 series and PowerBook 190 and 5300 series machines.  I didn't even have a Power Adapter for the 190 / 5300 series machines, so although there were 9 total machines in the lot, I could not do power on testing.  I was able to find an original Power Adapter on eBay for a reasonable price, and so I purchased it knowing that having the ability to work on and test the machines (even one at a time) would justify the expense.  Also, I was hoping to reverse engineer it a bit to see how to make a cheaper power adapter from parts since these are of a type and vintage that's getting harder to find.

When the power supply arrived, I started doing intake on these machines.  It was exciting to go through all the machines and see how many would start and what kind of condition they were in.  To make a long story short I was able to get 3 working PowerBook 5300s and one working PowerBook 190 out of this lot.  There are also several more functional screens and some housing parts, but not enough parts to build another working computer.

It's been fun to work with these machines.  I find that the "last of" machines are often as interesting as the "first of".  In this case the PowerBook 190 is the last of the 68K Macintosh PowerBooks, and the 5300 is the first PowerPC based PowerBook.  The 190 didn't have an active matrix LCD so that makes for a compromised experience, but I've quite enjoyed working on the 5300s as these are all Active Matrix screens.  I know the 5300 has a reputation for being the worst Macintosh Laptop computer ever released, but I really enjoyed working with them, perhaps because of my lowered expectations.

Perhaps one of my favorite things about these machines is how easy it is to service them.  These really were designed with service in mind, and it doesn't take that long to strip one down to parts.  For two of the four machines, I had to do a main logic board swap because the metal frames had been broken and it really didn't take that much time.

The PowerBook 190 / 5300 machines use a standard 24V supply with less than 2A draw.  They also use a small barrel jack which is center positive.  The barrel jack has a 3.8 mm OD, which appears to be a standard size but it's recessed into the body of the laptop in a hole that has only a 6.6 mm diameter. All of the field replaceable barrel jacks that I can find online have an 8 or 9 mm housing for the wires that will not fit inside the recessed hole on the Macintosh.  I have not been able to find an off the shelf connector that will work.  I looked through my stash of saved adapters and cut off adapter ends, and I found only one over-molded connector with the right jack dimensions, but I had to shave down the outside of the connector with a razor knife before it would fit in the recessed hole.  Let me know if you are aware of another work around, or a source of inexpensive 190/5300 compatible power adapters?

The next unresolved challenge is the battery compartment.  I certainly don't want to put used batteries back into the machine, but all of these machines have a gaping hole were the battery is supposed to go in.  One of the things that I like about the PowerBook 1xx series is that the battery door can be removed from the cells and replaced on the machine to create a finished look without batteries present in the machine.  This battery pack lacks that feature.  I did test the one 3400 series battery that I have and it fits in the case.  I think the best solution here would be to 3D scan the housing of that battery and 3D print an empty shell of this size to fit, just like the "Weight Saving Device" for later machines.  Unfortunately, I do not have access to a 3D scanner.  Any other ideas?  Let me know in the comments below, and in the meantime, it's off to the 68KMLA forums for me to do some reading!

I Bought More Than 100 Laptops

John from Roadkill Inc is someone that I’ve gotten to know over the last few months.  He lives here in the Minneapolis / St. Paul area and we share a love of Retro Computing.  See his YouTube channel here...  I've been doing repairs (and attempted repairs) for John in exchange for broken retro computers, at least one of which has already been featured on my bLog, the Orange Clamshell Trash to Treasure article.

John is downsizing his collection, and he offered various portions of his collection of low-grade machines in order to avoid having to move them.  He offered me a deal I couldn't refuse, thanks John!  I purchased 118 laptops, and used my minivan to move them...

If you've watched John's channel before, you'll know that these have all been recovered out of the eWaste stream at a recycler.  Some of the machines he gets are in good shape, but these are all C and D grade machines, so until I've had a chance to clean each one and try to power it up and evaluate, hauling them like this isn't going to cause significant additional damage.

Here's another picture setup in the garage at home...

In the foreground, we have G4 White and Translucent iBooks from the early 2000s, mostly 12” machines, but some 15” iBooks.  The Aluminum machines are 15" Powerbook G4s from the early 2000s.  These machines are about 20 years old, and have just started to regain popularity as these are the last machines that can run Mac OS 9.2 in the "Classic" environment on Mac OS 10.  To the right, there are a bunch of PowerBook G3s, and behind on the table saw are the grey and black 68k and early PowerPC PowerBooks.

For intake, I’m cleaning the outside of each computer using water and a microfiber cloth to get most of the dirt off so that they can be stacked without causing additional scratches and damage to one another.  Then, I’m powering each machine up and writing a post it note about what I observe.  This is just a condition check, there is no significant troubleshooting happening at this stage, just trying to figure out how many of these have signs of life, how many good screens there are, and if there are groups of machines that should be combined to make one good machine.

Just this intake process alone has proven to be several weekends worth of work, but I got my car back in the garage, so it’s going well!  I’ll provide some highlights from the oldest machine in the lot too the youngest...

The oldest classic Mac in the lot is a PowerBook 150.  I’ve already fixed up and rescued a PowerBook 145B from John that I built up out of two recycled machines.  The screen is a bit weak and flickers on my 145B, so I was hoping to use the screen from the 150 if it was not smashed, but unfortunately, they are not compatible. However, I still may be able to use some of the case plastics off the 150 to improve my 145B.

There are two generations of PowerBooks for which I have no power supply, and can’t do power up testing.  The PowerBook 500 series, and the PowerBook 190 / 5300 series.  The four 500 series machines that I have are incomplete and I won’t be able to make one functioning machine out of them.  Also, this series has a bit of an odd 4 pin plug, so I may take a pass on this repair and trade these parts machines to another collector.  The PowerBook 190/5300 series machines use a 24VDC barrel jack, I will have to sort through my saved power supply drawer and see if I have something that can work for this.

There were four 1400 machines, and I was pleased to see three 3400s as well.  The 1400s are a gap in my collection and I think I’ll be able to get one or two running machines out of this lot, as there are two working screens here.  The 3400s are not complete machines, none of the three had a keyboard, so I could not do power on testing.  I already have a 3400 I got off Craigslist last year. That computer has a screen that works, but is a bit flickery (it probably needs a recap) Maybe there will be a screen here that I can use and I’ll certainly keep a parts machine.  So there are a couple of projects in this group of machines.

The G3 PowerBooks use the same power supply as the Clamshell G3 that I have.  These machines are in rough shape but there are machines that boot and there are good screens in the lot.  I will have to combine parts from 3 or maybe even 4 machines in order to get one running computer, so this will be a lot of work!  I’m hopeful that I may be able to get 2 working Wallstreet machines and 2 working Pismo machines out of this lot.  At this time, I don’t have any of these black G3 machines in the collection, and this is one of my favorite eras of Retro so these are the machines I’ll probably work on first when I do get through intake and into the process of actually fixing them.

There are 39 iBooks ranging from the translucent to the solid white ones.  Although I did not bLog about it, I've already repaired five of these white iBooks from a previous lot from John and I enjoy working on this generation of machines. These are considerably more repairable than the current offerings from Apple, who have adopted an Anti-Repair stance.  While I'm on my soapbox, have you signed the Minnesota Right to Repair petition yet?

I have completed intake on these machines and as expected they are be in better shape.  Yield on these should be about 2/3s of the machines, but again these are recycled machines, so there are no museum pieces here.  I will likely keep some of these machines, but if you live in the area, keep an eye on Craigslist as I plan to sell some of these off to fund further adventures in Retro Computing.

There are 43 15” Aluminum PowerBooks.  These are the last of the PowerBooks, and the last PowerPC laptops that Apple made.  After completing intake on these, I’m hoping to get about 1/2 of these machines working (given enough time for repairs).  The biggest challenge with these is that dents in the top cover of the laptop can cause dark spots on the display even if the display isn’t smashed.  If anyone has any tricks for pulling dents out of Aluminum PowerBooks please let me know in the comments.

Well, as you can see, this purchase has left me with projects that should last a good long while.  I’ll keep updating the bLog about these repairs as I go along.  Thanks for reading, and please do let me know in the comments if you have you any good memories of these machines, or if you have any suggestions for me about how to do the repairs?

Compaq Deskpro XL 590 - Pentium Workhorse

I recently acquired two Compaq Deskpro XL 590 computers from Free Geek Twin Cities, the pair were labelled as a Project PC, and sold at an enticingly low price.  I was pretty excited to see this because I'd recently damaged my Epson Pentium 75 machine, which was a favorite in my Retro Computer collection, and one of the first that I'd acquired.

The Compaq PCs were in pretty rough shape, as you can see here...

This is an interesting system, it's got a processor on a slot but it's not a passive backplane computer.  There's quite a bit of logic on the mainboard, including; audio, SCSI, IDE, and Ethernet.  The CPU and RAM are on the processor slot, which is almost a full length card.  Modern Classic on YouTube recently did a series of vides on this hardware which you can find here, here, and here.  He started out with a 486 and upgraded to a Pentium 100.

My systems are a Pentium 90 with 16 MB of Built in RAM, these systems have two PCI cards slots, and the rest are EISA slots.  I've never had an EISA system before, so that was an interesting aspect of this build. My goal for this machine is to get Windows 95B running and have a boot menu configuration for DOS gaming or for starting up the Windows 95 GUI.

I had quite a few interesting challenges getting this computer going.  The first was the BIOS setup program.  The BIOS setup program for this computer shipped on Floppy Disks, and can be installed into a small partition on the hard drive, but as with most recycled computers, these machines shipped without a Hard Drive or any floppy disks or documentation.  So,  I started Googling around and used the Wayback machine to figure out what the last set of drivers for this board were.  Having this information was only the start of the struggle, since HP has turned off the FTP site where they had been hosting the old Compaq Softpaqs for many decades.  I asked for and received some good advice about locating these files on the Vintage Computer Forums.

One of my goals for the system is to use it as a Disk Imaging system with a Go-Tek floppy drive emulator with FlashFloppy firmware loaded on it.  I have a couple of these, one lives permanently in my pentium, and the other is a "floater" Go-Tek that's used for building and testing systems.  Using the Go-Tek, I was able to convert the odd Compaq Softpaq Executable files into the more useful IMG Disk Image file format.

I have collected up the drivers I needed to build a Windows 95B machine, and I will link the file here, this includes:
System Diagnostics SP16085
System Configuration Disk 1 - 4 SP6144
Firmware Update (Final 4/7/1997) SP3642
Matrox Millennium PCI Video Card Drivers for Windows95 SP2754
Onboard Ethernet Driver SP1649
Onboard SCSI Driver SP1664

Once I had the disks needed, it was time to start the build.  I wanted to use Compact Flash media for the Hard Disk Drive, but I had no end of problems with a couple of off brand devices that I tried, so for now I've defaulted back too a 6GB Quantum Fireball IDE drive that I had in the parts bin.  The System Configuration utility was able to recognize the drive and startup without error.  Once the System Configuration utility is able to start without error, if there's a blank drive it will offer to install the System Configuration into a partition on the Hard Drive, which I did for convenience.  At that point you can Fdisk the rest of the drive and setup your partition for Windows 95.  This part of the install was normal and painless.

I've moved all the goodies from my Epson computer over to this one.  I've added 128MB RAM, a 52X CD-ROM, a Go-Tek, a newer ISA SoundBlaster 16, a 3Com 3C905C Fast Ethernet card, and a Parallel port Zip drive to use for "Sneakernet".  The case cleaned up pretty good, although it did have some paint missing on the corners...

I'm quite happy with how this machine has turned out.  I still have quite a bit of tweaking left to do to get all my DOS games back up and running, but that is a big part of the fun.  It's great to have a running Pentium class machine back in the stable!

Here's the machine running Internet Explorer 4.0 and using the excellent new FrogFind.com search engine for Retro Computers from Sean at Action Retro...

Next, I need to get the Boot Configuration Menu going, I'll probably copy something from Phil's Computer Lab's MS-DOS Starter Pack.  Also, I've ordered some Industrial CF cards to try again too move the Hard Drive over to Solid State media, but in the meantime, this machine should be tons of fun.

My first CP/M Computer

A few weeks ago an intriguing post popped up on Craigslist.  It was for a CP/M computer that someone here in the Minneapolis / St. Paul Metro area had built up from the board level in 1983.  I believe the builder re-used a piece of old test equipment as the Chassis, and perhaps the power supply that was in the Chassis as well, but the computer itself is a Megatel Quark 100 computer.  This was a Canadian firm.  The computer is a Z-80 based system with 128K of RAM (64K available to CP/M), and two Teac 360K floppy drives.  (I'm still not sure what the formatted capacity of the drives is, since I'm a CP/M newbie.)

At some point the previous owner had recycled the Monitor.  I don't have an MDA / Hercules compatible monitor in my collection, so I ordered and waited for an MCA2VGA to arrive from TexElec.

Once I got the video adapter and a 9 pin male to 9 pin male straight cable, I was able to fire the machine up and test it for the first time, it boots and runs well...

There appears to be an issue with the Horizontal Sync timing on the MCA2VGA adapter, as the last few columns of text on the right hand side are cropped.  Also the video is compressed vertically too about 1/2 of the height of the screen, so I'm not sure what's going on there.  The manuals for the Quark mention specific horizontal refresh timing, but I'll have to dig in on what the timings are supposed to be for MDA / Hercules in order to understand why this isn't working on MCE2VGA.  I'm also on the lookout for a period correct monitor.

The next challenge was the Key Tronic foam and foil keyboard.  Several of the keys were not working...

I've restored a similar keyboard before on my Compaq Portable from the same year, and once again TexElec came to the rescue with their Foam and Foil replacement pads.  Waiting for the pads to come in gave me the opportunity to take the board completely apart and clean the housing and keycaps.  After replacing the pads and re-assembly, the board is working like new, although there's some wear and tear...

I'm quite happy with how this turned out given that the keyboard is over 35 years old!

The next challenge was that the builder of this system mentioned to me that the BIOS is on a Floppy Disk.  The computer won't boot at all without the customized, appropriate BIOS for the peripherals that are wired to this specific build of the Quark.  This left me with a nagging fear that as the floppy disks fail, I'd loose the use of this classic computer.  I'll write a separate bLog article about my new SuperCard Pro Disk Imaging setup, but too make a long story short, I was able to image and restore Bootable CP/M disks for this machine, and capture and archive all the disks that came with this system, so that is a relief.

That wraps up the story so far for my first CP/M computer.  It's working well enough that I can dive in and start learning about CP/M, the precursor operating system to DOS.  There's alot of good information online, and I'm planning to start with "The CP/M Handbook with MP/M" by Rodney Zaks.

On my To-Do list for this computer:

Find an appropriate monitor that can be adjusted to show all the text, or determine why MCE2VGA isn't displaying the image correctly.

Find a Go-Tek equivalent for 360K 5 1/4" drives so that I can replace one of the floppy drives with a solid state drive.

Please let me know if you have any suggestions for me about this computer, or any questions, Thanks!