The 286s are Coming

I've been on a bit of a tear with 286 PCs over the last couple of months.  Actually, I'd planned one of these repairs over a year ago when I got an ALR Fast 286 at an estate sale in the summer of 2022. This was a 286 machine from 1988, and I had been able to get that machine pieced back together and working but it was experiencing lock ups.  So I had been on the lookout for a nice 286 board to use as a replacement for that machine.  I'd purchased a board that needed some work, but that was yet another project that had been sitting for months waiting for time to do board level work on that.  But in the meantime, Free Geek Twin Cites came through once again with a "Project PC" 286.  It was an incomplete machine from 1990, but it had the motherboard, RAM and a functioning Floppy Disk drive, so I was happy to get it.

Shortly after that there was another 286 Project PC at Free Geek that was also incomplete, but included a nice case, Power Supply, and most of the computer.  I purchased this machine as well, thinking that I'd have enough parts already at home to build out both PCs.  One of the oddities of this era is that sometimes a 286 just isn't quite powerful enough for higher resolution VGA graphics, so I had been torn about rebuilding the 286 with VGA or CGA/EGA graphics.  But since I got the second machine, I would no longer have to make that decision.  I could configure the faster machine from 1990 as a VGA machine and the slower machine from 1988 as a CGA/EGA machine.

I did the rebuild of my existing 286 machine first with a target date of 1990.  The "new" motherboard from Free Geek has a 16MHz 286 with 4MB of RAM on it.  I was able to re-use the external battery pack I had previous built for the machine and the ATI All-In-Wonder VGA card.  There is a nice complement of ISA cards in the machine, including a FDD/HDD IDE controller card, a Serial Parallel I/O card, a more modern 3Com 3C509 Network card in it, and I added an CF to IDE card adapter instead of a hard drive.  The CF card is 256 MB and I experimented with the BIOS settings to get 200MB usable capacity from it.  The sound card is a more modern Sound Blaster Vibra 16 CT4170 which is less expensive than a period correct Sound Blaster.

I'm very happy with how the machined turned out, and it runs fast and stable...

After getting my "best" 286 running, I started on the more basic machine targeting a build date around 1988.  This PC is a 286 at 12MHz. It has 640k RAM, and I opted to stick with a CGA / EGA card.  The HDD / FDD controller and Serial Parallel I/O cards in the machine are period correct although again I did opt to install a CF adapter in order to make it easier to load software from my modern computers.  Given the low RAM configuration I won't be installing a Sound Card or other peripherals at this time, but the machine is working good and it looks really nice...

The final project for this article is another 286 PC, a Compaq Portable II.  Thanks to fellow collector Steve H. who passed this machine to me in a lot of luggable computers.  This machine was starting up but it had an error on the screen and the floppy drives were in unknown condition.  I had heard that it would have Citizen Floppy Disk Drives and that these drives were notoriously difficult to service, but when I opened the PC, the floppy drives were made by Canon.  I cleaned and lubricate the drives and after this both drives boot up and run very well, so that ended up being a non-issue.  This generation of Compaq PCs does not have the BIOS setup program in ROM.  When I was restoring my Compaq Portable I machine back in 2020, I had already downloaded and created 360K Floppy Disks for the Compaq Diagnostic and BIOS setup programs.  One of the startup error codes was related to the clock.  Thankfully, Compaq used Tadiran batteries, which I have never seen leak.  Even cooler than that, you can still purchase a replacement cell today.  Once I had installed the new Tadiran cell I was able to go into the Compaq Diagnostics and set the time, date, and machine configuration so that there would not be any error messages at start.

Since this was the lower cost Compaq II without a hard drive I knew I was going to want to install some kind of permanent storage to make the machine more useful.  Since the machine had an IDE controller built in I was able to add another CF to IDE adapter, as before with the other 286 machines.  This one is configured in the Compaq BIOS to give about 120MB of storage, which is more than this machine ever would have shipped with.

The machine boots up and runs great, I'm very happy with how it has turned out...

I think this third machine will conclude my 286 adventures for a while.  Let me know if you have any 286s, or if you have memories from that era of computing.  What games should I load on these PCs?  What programs would make them more useful in 2023?  Leave a comment below, or feel free to reach out to me via the email address in my Bio.

Building a New / Old Single Board Computer

As readers of my bLog will know, I have a soft spot for Digital Equipment Corporation's hardware.  I'm the fortunate owner of multiple terminals and the PiDP-8 and PiDP-11 kits.  At VCF Midwest this year I met a guy who explained to me about the RetroBrew Computers SBC6120 Single Board Computer built on the Harris 6120 Microprocessor.  He had built one and had parts left for multiple kits.  He sold me a complete kit with all the parts.

The documentation for this kit is very good.  I'm glad that I read through the instructions before I started though because this is not a beginner's kit.  And there are notes about the RBC revision of the board that you have to read which superceed the original documentation, so you need to go back and forth between the updated notes and the original detailed documentation.  The traces on the board are very small and the advice about using a fine tip on the soldering iron and a fine solder was very helpful.  My build went very well.  I spent one afternoon doing the bulk of the soldering, then cleaned the board and set it aside.  I came back the next day and did touch up soldering and more cleaning.  I also spent time re-reading the "bring up" instructions and the jumper settings required.

I brought the board up in steps using the described procedure and it worked right away.  I was very pleased that I'd gone slowly double checking the work along the way. I'm sure that taking my time ended up being less time and certainly less frustrating than troubleshooting a design that I'm not familiar with.

I'm in the enviable position of having to decide which terminal to pair with this system and since my VT100 is tied up with the PiDP-8 I went with the VT220.  The documentation does point out that you need to use 7-M-1 in order to get the proper display from both the boot loader and from OS/8 after it starts.  

There are three different disk images linked from the RBC page about the SBC6120.  I used a Windows 10 computer to write these out to some small CF cards that I had on hand.  At first I thought that my disk images were not working, however the root cause ended up being that I had not saved the serial settings in the terminal and when I cycled power it went back to 8-N-1.  Once the serial settings were restored and saved to 7-M-1, I was able to get output from all three of the boot disk images linked above on the RBC page.

I'm quite happy to have one of these PDP-8s on a Chip, it should be a great learning platform for the platform and the OS/8 operating system.  Perhaps someday I may even be able to own "Real PDP-8" hardware.

Let me know if you have any stories to share about this platform, or better yet join us on the Vintage Computer Forum and let us know "What did you do with your PDP-8 Today".

Building an Original Macintosh 128K - Failure, Learning and Eventual Success

A couple of years ago (Jan. 2021) I got a Macintosh 512K from a friend and fellow collector, Steve H, who I met through Free Geek Twin Cities.  I've bLogged about this machine and what I know of it's history before.  It's been the earliest Macintosh in my collection and I've enjoyed it quite a bit.  Also it's been popular with my guests who have nostalgia for this machine.  It has a place of honor in my limited display area and I've occasionally been asked "Is that the Original Macintosh"?  I've had to say no and explain that it's the second Mac, but that is looks identical on the outside and that it came out in the first year of the Mac, 1984.

So, I've been considering either downgrading this machine or finding another original 128K machine.  One of the main hurdles to performing this downgrade was that this machine had a (slightly) more modern 800K Double Sided Sony 3 1/2" floppy drive in it and the original Mac can only work with the original Single Sided Sony 3 1/2" drives (400K drives).  So this project stayed in the idea phase for more than a year.  Along the way I was able to acquire a 128K Logic Board, again thanks to Steve H, so that part of the puzzle fell into place.

In the middle of last year (Aug 2022), I was able to acquire another Macintosh 512K, a Craigslist find.  The seller told me that he had been trying to get it working but struggling and that he was giving up on the project.  When I got home and started to dig in on the machine it became apparent that he had tried to service the early 400K Sony Floppy Drive but it still did not work.  I also spent quite a few hours working on that drive and failed to bring it back to function.  In hindsight and after much learning and some good advice I realize that I should have spent more time cleaning and lubricating the drive.  I mistakenly thought that the drive needed a recap but when I performed the recap the drive head movements became erratic and the drive could not read a disk any more so I set the drive aside for the time being.

As a next step, I purchased a "lower cost" non-tested 400K External drive from eBay.  After spending time cleaning and getting the Mechanism somewhat functional the drive would still not read pre-formatted disks.  I made another bad assumption and mistakenly thought that this was a symptom of a drive alignment problem.  I broke the threadlocker from the Track 0 position sensor and moved that in an attempt to realign the drives.  After spending quite a few hours struggling, I also set this 400K Floppy Drive aside and the project went on hold again.

The next chapter of this repair saga begins at VCF Midwest this year (Sept 2023).  I was reluctant to buy more 400K drives because of how much time I'd spent and how little progress I'd made on the first ones but I had a very informative conversation with Steve H. at the show.  He has repaired many of these drives and he let me know that he's never had to recap one and never had drive alignment problems.  At this point, I realized that not only was I "barking up the wrong tree" but also that I would probably need another drive mechanism in order to move forward with the project.  On the final day of VCF when people had started packing up there was a person selling a large number of old Macs and they were willing to take offers.  I got a great deal on a lot of items from this seller that included a 400K drive mechanism that had not sold earlier in the weekend.  As a bonus they included a second 400K mechanism, so I had two more drives to try to service and repair!

Back at home after VCF I was better educated about what to do (and what not to do) with Sony 400K drive mechanisms.  I spent more time cleaning alot more and I thought I'd share some of my lessons learned about the drive cleaning process.  Cleaning for these drives has two phases, the first is cleaning the drive inject / eject mechanism.  The grease on these drives that I've serviced has all been dried up so hard that the mechanism won't move at all.  I used alot of Isopropyl Alcohol to try to remove as much grease as possible then start lubricating the mechanism with 3 in 1 oil.  Getting the mechanism loose starts with the small flipper mechanism half way down the right hand side of the drive as you face the front of the drive.  Once the manual inject / eject works smoothly the drives can be powered up and run.  Phase two of the cleaning is focused on the leadscrew that moves the read / write head, none of these drives worked until I had carefully cleaned and put some lithium grease on to that.  I now had 400K drive mechanisms that I needed to move forward with the project!

So, by replacing the drive and swapping the logic board, I have my Original 128K Macintosh from 1984 up and running, along with an External 400K floppy drive...

It's cool to be able to boot the original Mac Demo disk as this is the only computer I have which can run this software.

Do you have any memories of working with the original Mac?  Do you have an original Mac?  Let me know in the comments below, or send me an email, my email address is in my Profile on the right side of the screen.

Vintage Computer Festival Midwest 2023 Recap

I've just returned from Vintage Computer Festival Midwest 2023.  I had a great time during my first year as an exhibitor.  The thing I enjoyed most were seeing so many people enjoying the computers I brought along...

Many types of people enjoyed the computers, from those who have never gotten to work on a NeXT machine because they were too young to those who had used the Apple Power Mac G3 w/ the 21" Studio Display back in the day.  It was so much fun hearing about peoples memories with these computers,  answering questions, or hearing small parts of many many different stories.  It was a really great time.

I was also able to connect with some of my favorite YouTubers, purchasing a boxed game from David Murray (the 8-bit guy), meeting Adrian Black for the first time, and even recording a YouTube Short for RetroTech Chris, in addition to hanging out with Steve from Mac84 and Ron from Ron's Computer Videos who I had met 2 years ago at VCF Midwest for the first time.

Also, I was able to purge several project machines that I'd lost interested in onto the "Free Pile".  Hopefully my failures can become part of a successful repair or refurbishment for another collector.  One of my friends, Matt, had a table right next to the free pile and he gave me a couple of items off the pile that he had recovered.  The crowds were so large that the good stuff came and left the free pile pretty quickly!

One goal I had set for myself was to buy only parts and pieces for projects that I already had pending.  I didn't want to leave VCF with a bunch of new projects and I was able to accomplish that goal!  I found many parts and pieces that I was looking for, mostly on Sunday.  I waited till about 11AM on Sunday to make offers.  With only a few hours left in the show many of the vendors were happy to make deals.  I have 4 or 5 projects now that I can complete with parts that I found at the show, including hard to find parts like: a DEC keyboard w/ a PS/2 port, a SUN CRT, and a New Old Stock Floppy Drive.

In summary I had a wonderful time at VCF Midwest 2023.  There were some growing pains that go along with the number of people at the show but my overall impression was quite positive and I hope to return as an exhibitor next year with a completely different set of computers to show and to share.

Preparing for VCF Midwest 2023 - September 9 and 10

I'm heading back to VCF Midwest this year and I couldn't be more excited about it.  I consider the year of the pandemic (2020) as my first VCF because I eagerly watched all the sessions (the event was online only that year).  The following year (2021) I attended for the first time in person.  I was able to pickup a NeXTstation during that show and meet so many interesting people including regular collectors like myself and a few YouTubers like Clint from LGR and David Murray, The 8-Bit Guy.  I missed last year (2022) but ended up buying several machines before the show from a local friend who has been downsizing his collection.

This year I decided that I'd like to try to exhibit.  I was inspired by a couple of different sources.  The first was a history book that presents computer history as a series of computing stories.  This book made an impression on me this year and left me thinking about the importance of teaching computer history to the next generation.  Last year Bill Degnan gave an interesting talk about how to build a Vintage Computer Museum at VCF Midwest.  I found his idea of building exhibits one at a time and looking for opportunities to display them pretty interesting and so this year I'm taking advantage of the opportunity at VCF Midwest to bring this exhibit...

The title of my exhibit this year is "Engineering Workstations of the 1990's".  This was a time when I was going to school and early in my career.  I really wanted one of these specialized machines, but never had anything other than a PC.

The first computer I'll be displaying is the NeXT NextStation from 1990 I've already mentioned.  It's had a bit of preventative maintenance since its last appearance at VCF in 2021, and it works great.  Come and check out some of the applications I've installed and maybe even surf the web a bit with frogfind.com.

The next computer I'll be showing is the Digital Equipment AlphaServer 300 from 1996.  This machine is running Windows NT 4.0, an OS that I experimented with back in the day (on PC hardware) but never used at work.  As I have learned about the history of Windows NT and its chief architecture David Cutler I've wondered if the DEC Alpha may have been the primary development target for Windows NT.  There isn't very much software for the machine, but you can come and try out what I've been able to install so far at VCF.  Perhaps we'll find some other applications to install during the show.

Finally, the last computer is an Apple Power Macintosh G3 Blue and White from 1999 that I have recently upgraded.  The G3 B&W is a machine that I had at home back in the day and shows an amazing progression during the 90s from the expensive and rare NeXTstation to the much more affordable G3, becoming so affordable that it could be purchased as a home computer.  Come and check out all the different OSes I have installed on this machine, including Rhapsody.

There is an interesting "what if" scenario about a pivotal event in computer history that ties these machines together but I will save that story for the show.  Stop by my table if you are there!  I'll be in the "Big Iron" room, table D33.

Power Macintosh G3 Blue and White from 1999

A couple of years back a friend sold me a Power Macintosh G3 Blue and White from 1999.  I owned this machine back in the day.  It was my first computer that I bought coming out of College.  I had been a PC user all throughout college and I switched because my employer at the time had me using Macintosh and I had gotten used to them and was enjoying Digital Video as a hobby at the time, where Apple had a significant ease of use advantage over the PCs of the time.

But back to the present day.  As soon as I got this G3 B&W I put a HDD drive in it and installed Mac OS 8.5, the first version of software that would have shipped with this machine.  I played with the machine a bit but then put it away.  In the meantime I'd been able to collect the period correct keyboard and the horrible puck mouse to go with this machine.

A recent acquisition from a garage cleanup that I did with my friend John Bumstead gave me reason to get this machine out again, the matching Apple Studio Display 21" monitor...

I don't know that I'd ever seen one of these displays in real life, and if I did it would have been very briefly.  When I owned a G3 I had it paired with a 17" Flat Sony Trinitron CRT.  That CRT had an amazing image, but it was in a boring beige case.  This CRT is also a Trinitron, and it's an absolute beast to move because of how heavy it is.

Several recent YouTube videos have been instrumental in giving me the knowledge to get the G3 working better.   I'd had trouble getting flash storage options working with this computer and wondered why till I watched a video where Sean from Action Retro talked about getting Rhapsody running on the G3 B&W.  In this video Sean explains that the original G3 B&W machine had a buggy IDE controller chip.  I checked the part numbers on my board and sure enough this is one of the machines with the buggy IDE chip.  That being said, Sean tried and struggled with SCSI on the machine, too, so that left me with an open mind about SCSI vs. IDE on this machine.

Mr. Lurch has strongly recommended the StarTech SATA to IDE bridge for Power Macintosh machines as a reliable solution for getting flash storage into vintage computers.  I had purchased one to keep on hand which I paired with a low cost SATA SSD from Free Geek Twin Cities.  This gave me a working IDE flash storage solution for this machine for about $40 total in parts, but that was only the beginning of the fun.

Sean @ Action Retro has a video investigating all the early versions of Mac OS to see how the UI had evolved over the years.  He did this online in a browser, but as we all know doing this in hardware is more fun.  The Power Mac G3 B&W supports every OS from 8.5 to 10.4 as well as Rhaposdy versions so there is alot of scope for interesting OS explorations on this one machine.

After a great deal of experimentation with an IDE HDD, with the SATA SSD explained above, and with a SCSI HDD I was able to get the folowing OSes all installed from CD media and booting on the machine:

MacOS 8.5

MacOS 9.1

MacOS Server X (Rhapsody)

MacOS X (10.0)

MacOS X (10.2)

MacOS X (10.4)

It's been alot of fun getting this machine configured and having a look at MacOS Rhapsody for the first time.  This OS shows alot more of the elements of the OpenStep operating system from NeXT as it slowly morphed into the MacOS X that Mac users are still using today.

I hope that this machine will be part of my exhibit at VCF Midwest this year, but more to come on that topic in the very near future as VCF Midwest is only a couple of weeks away on Sept. 9&10, 2023.  If you are in Chicagoland for that event come by my booth and say Hello!

Macintosh Quadra 800 Restoration

I was recently able to add a Macintosh Quadra 800 computer to my collection.  This computer came from another collection that my friend John and I helped clean out.  I'd been on the lookout for a 68040 based computer that was on the A/UX Compatibility list, but I knew that the Quadra 700 would be out of reach for me price wise due to its popularity.

As I have previously blogged about, I've already restored a Macintosh IIci System that I run A/UX on.  This was a fun project and I learned a ton about classic Mac hardware, but it's not the fastest Apple Unix experience, so I've had an '040 machine on my wish list since that project ended.

My Quadra 800 has had a hard life, there's some light rust on the shielding inside the case, but it's nothing as bad as two of its sister machines which had been stored on the ground in a shed for many years.  But despite the poor storage conditions this machine still boots up and runs.  For some reason the machine had three video cards installed, so with the built in video this machine from 1993 would have been able to have four monitors attached.  The hard drive had died, so I was not sure what the machine had been used for, but a four monitor setup would have been interesting and unusual!

The restore process on this machine was pretty straightforward.  I was able to find the Apple Service Source manual online and used that information to take the machine apart.  While it's not at all easy to take apart compared to the Macintosh II series, it's really not that bad compared to PCs of the time.  After I had the machine all apart I cleaned the case with warm soapy water and dusted the main logic board.  The logic board on this machine doesn't have any Electrolytic caps so I didn't have to recap this machine.  I replaced the Tadiran Clock Battery w/ the same brand, so this computer should be good for another 30 years.  A couple of the drive bay covers were loose so I used Hot Glue to attach them from the inside of the case, it looks really nice on the outside and they drive bay covers are secure.

The floppy drive in this unit needs attention but I had another manual inject drive ready to go so I swapped that in.  I will service this drive at a later time.  This machine came without a hard drive.  I decided to use the ZuluSCSI Hard Drive replacement in this machine as I had one on hand, but also I like the mounting options on ZuluSCSI better than the options for BlueSCSI V2.  I can attach Standoffs and zip tie the ZuluSCSI down on the bottom of the machine with the SD card facing out the back of the computer.  Perhaps if I had a 3D printer this wouldn't be as big of a deal.  But as things are now, this makes it alot easier for me to experiment with alternate OSes, swapping SD cards for MacOS and Apple A/UX.

One other upgrade was to go through my supply of RAM and see if I could find matching pairs of FPM RAM, I was able to find another pair and bring the machine up to a total of 104 MB of RAM.  The memory check at power up takes quite a while about 30 seconds from power up to the chime, but it's a worthwhile compromise to have this machine near its max capacity.

One quirk with this machine is the strange Ethernet connector on the back.  It requires an Apple AAUI Media Adapter so I installed that with this machine and got Internet going with MacOS 7.6...

Getting Apple's Unix A/UX to boot was almost too easy with the Zulu SCSI, as I had a backup of the Disk Image from the BlueSCSI on my Macintosh IIci.  I was able to copy that onto another SD card, install that into this machine and it booted the first time.  There was a warning message from A/UX about the hardware change, but it made those changes automatically and after a single reboot the machine came right up and ran.

Remaining tasks that I have for this build are to configure networking in Unix.  This should enable me to transfer program files or build new tools on this Unix as it is missing alot of the "quality of life" tools that I've gotten used to with modern Linux distributions.

Retro PC Repairs - Know when to hold 'em, Know when to fold 'em.

Things were quiet here on the bLog in April.  I was busy working on computers but I experienced a string of repair failures.  As discouraging as these can be I think it's important to write about them as a way to document lessons learned and to perhaps help others who may experience similar challenges.

The machines were a Compaq 386SX machine, a TI Travelmate 486 laptop, and an IBM PS/note Laptop.

The Compaq Deskpro 386S/20N was labelled as "not working, needs recap" but as my friend John Bumstead has said, when we are troubleshooting machines we need to disregard notes on the machine and do diagnosis ourselves.  In this case however it was obvious by doing a visual inspection on the board that it did need a recap.  As I removed the capacitors it became apparent that this board had suffered alot of damage from capacitor leakage.  There were many, many lifted pads and sections of the board that were heavily corroded with traces coming up.  I did some trace repair during the recap, but it was not enough to bring this board back.  I'm not sure if there are Vias that are missing or if the board has middle layers but after spending many hours with the board with no signs of life, I'm setting this machine aside for now.  This is such a cool little small form factor PC that I have put this on the wish list and I'll be looking for another parts machine, although I wouldn't be willing to pay to much knowing how bad the caps were on this particular one I had here.  Sadly, the end may be near from these Deskpros, although I'm hopeful that ones stored in better conditions may have faired better than this one.

The next repair attempt was a TI Travelmate 4000 Laptop.  This machine was reported as working but the Floppy Drive was not reading disks.  The previous owner suggested replacing a belt inside of the floppy drive.  I have done this on larger machines and so I thought this would be a repair I could handle.  I even found a bLog article explaining how another owner had been able to do this.  For me, I personally feel like a retro project is not complete till the machine can be rebuilt using its own  drives, so I started in on this repair knowing that the machine was partially working and could be left as-is.  Unfortunately, after getting all the way into the machine I discovered that I was not going to be able to take the drive apart far enough to get easy access to the belts.  I was not able to thread a belt onto the machine from the floppy slot although I did try for quite some time.  During the re-assembly process I also caused additional damage so sadly this machine will have to be split up for parts.  Although I'm very disappointed, I don't regret starting the repair for the reasons I've already described.  This is the only one of the three repairs that I consider a total loss.

The final repair attempt of these first three is an IBM PS/note portable computer.  This machine was described as "working for a while, then not working" The note indicated that they believed that the power supply circuit needed recapping.  This is also a repair that I feel quite comfortable doing, and did.  Sadly, after the Power Supply circuit inside the machine was recapped the machine still wouldn't start.  This leads me to think that perhaps the Power Supply Brick is also needing a recap, so this repair that is on hold, and not a failure (at least not yet).

After all these challenges I was able to turn things around a bit.  I bought a couple of "project" computers from a trusted local seller on Craigslist in my area.  He was selling two machines at low cost because he knew they had something wrong with them and needed repair.  I've had a high success record for machines from this seller so I jumped on them as soon as he listed them.

The first machine is a DTK KEEN-2530 machine from around 1991.  The reported symptom was that one of the four SIPP Memory Modules had a RAM chip broken off of it.  Since this machine is a full 32-Bit machine, a 386DX-25, it requires four matching memory modules in order to Post.  I decided to work on the memory issue before doing a through cleaning on the machine, but I did a light cleaning on the outside of the case and disconnected the power supply and tested it first before trying to fire up the machine for the first time.  

I've never worked on a machine before with SIP or SIPP memory, so I had to do some research.  According to Wikipedia and another source, this SIP is basically a 30 pin SIMM with pins soldered onto it.  My first instinct was to try to repair the SIP with the chip broken off, but after a careful examination that did not look easy with broken traces and multiple layers.  I tried searching on FleaBay for a part, but none were available at the time that I looked, so I started digging in on what I had to see if I had an equivalent.  It turns out the machine had 1 MB SIPPs in the 9-chip parity arrangement.  I was able to find a stick of very similar memory in my stock but the one I had was a SIM and not a SIP, and a 70ns part instead of the 80ns chips on the good SIPs.  I found some solid wire that would fit into the SIP socket and started soldering, adding 30 pins to this SIM memory to turn it into a SIP.  I was very gratified at the end of the soldering and leg trimming exercise to discover that this is a working system, my SIP was functional and the machine booted for the first time!  The connection is a bit flaky when I move the system around, so I've hot glued the home-made SIP to its neighbor in hopes that this will hold it in place better.  In the long term I may end up soldering the two end pins into the socket below to prevent movement.   I think this could have been avoided if I'd have had some lead frames on hand in order to cut and solder on proper leads instead of the solid core wire. but I didn't have those parts on hand.

The finishing touches on this build included desoldering a dead Dallas RTC and installing a socket for that, adding a 1.44MB Floppy Disk Drive, and testing the early Seagate IDE HDD in the machine.  The machine cleaned up quite nicely and is a good time capsule 386 machine.

The next repair candidate is an HP Vectra QS-16S from 1989.  This machine was reported to have a failed capacitor which released the "Magic Smoke".  After this failure, the owner powered the machine down quickly.  I find that this seller is very accurate in his descriptions of failures so I knew these symptoms would have been reported accurately.  What I didn't know what what kind of failure I was dealing with, my initial assumption was that it was a capacitor failure inside the Power Supply.  This made the purchase a bit more of a risk because HP machines of this era have a proprietary power supply, so if I couldn't find the fault and correct it then the repair may have to go on hold waiting for a difficult to find part.

So, as usual I started the repair by spending some time learning about the machine.  The HP Computer Museum is a great resource for these machines and did not disappoint with information about the HP Vectra QS-16S.  I also did a bit of light cleaning before starting to take the machine apart from inspection and repair.  As mentioned above, because I suspected the power supply, I didn't even try to test it, but immediately opened it up to look for blown RIFAs or other capacitors with obvious bulging or leaking, but there were none inside the Power Supply.  On putting it back together and testing I was a bit surprised to see all the voltages responding as expected, so I needed to dig deeper into the machine.

This machine has the processor and RAM on a daughter card.  I removed everything from the case and did some cleaning.  As I inspected the main board I noticed a burned surface mount capacitor (C1)!  It was near the keyboard connector on the main board and I can only assume it's part of the power supply section of the machine.  The cap was so burned that I was worried about not being able to figure out the value of it, but after a close inspection every other capacitor on the board had the same shape, size, and value, 22uF, so I was able to find a replacement cap from my stock and install that on the board.  I did some more cleaning as I reassembled the machine as this one had gotten quite dusty inside.  Once I got the daughter card and VGA card re-installed, I was thrilled to see the machine boot for the first time!

Once I started reattaching drives and devices too the machine, I entered another no-start condition.  After isolating the fault two one of the two MFM hard drives (identical ST-251s) I was able to remove the second drive get the machine booting again.  There was a burnt tantalum on the ST-251 board that was causing the machine to not be able to start.  I set the drive aside and came back to it later, but it didn't end up back in this machine.

The next hurdle was the Floppy Disk Drive.  As I've already mentioned in this article, it is important to me to have computers that can start up on their own.  The 1.2MB 5 1/4" Drive in this machine was cleaned and tested, but it is exhibiting some odd symptoms.  The drive spindle rotates and the heads are moving freely, but it can't read or format disks.  In the short term the easiest path forward (and probably the most reliable path forward in the long term) is to add a 3 1/2" High Density 1.44MB Floppy Drive to the machine.  This would have been one of the factory options, so I purchased a replacement drive and bezel kit at Free Geek Twin Cities and installed that.  Since this HP Computer does not have its BIOS setup program in ROM, I also made a couple of floppy disks from images on the Internet in order to set the BIOS settings and deal with Error messages on boot up.  The machine now starts and runs without error.  It's a great looking machine...

The picture above shows the HP Vectra up and running with my copy of IBM OS/2 Version 1.2, but my interest in and history with OS/2 is a story for another time.  

If you've made it this far thanks for reading and let me know if you have had any interesting repair successes or failures you'd like to share either in the comments section, or you can email me at the address shown in the Bio section of my bLog.

The Last of the CP/M Kaypros - Kaypro 1 (1986)

Due to the generosity of a fellow member of the Vintage Computer Forum, I recently re-homed a Kaypro Model 1 computer from 1986.  Despite its numerical sequence the Kaypro 1 (1986) is the last of the line of Kaypro CP/M machines that started out with the Kaypro II in 1982.

I also have acquired and restored a Kaypro 2X (1984) machine which I've previously blogged about.  This machine is still in my collection.  That experience lead me to feel pretty comfortable tackling another Kaypro project.  The previous owner of the machine let me know ahead of time about issues with the machine, but there was really only one problem, the A drive was intermittent and the machine wouldn't boot any more.  I'd experienced this exact same symptom with the other Kaypro.

It's important to get the Kaypro back to a state where it can make bootable copies of its own floppies.  Especially since this newer Kaypro has a newer ROM that requires slightly different version of CP/M (2.2U1) and it wouldn't boot off the disks that I'd made last time for my other Kaypro (2.2G).  Step one of the repair was to get the two drives out and inspect them.  The inside of this machine was clean.  The floppy disks both looked good the heads could move freely and the direct drive spindle motors were spinning freely.  There was noting obvious wrong, so I cleaned the heads and swapped the A and B drives around.  Swapping A and B on a CP/M machine requires both changing jumpers and moving the termination resistor pack on the drives.  Now the A drive was the drive with much lower hours on it.

It worked!  The Kaypro 1 booted the first time after swapping the drives, always a good feeling to get another machine booting again.  And this enabled me to do a bit more troubleshooting on the bad drive (formerly known as the A drive).  I used the COPY utility to copy the Boot & Extra Utilities disk over to the B drive.  The copy operation is slow on these machines but it went all the way to the end and then failed when it go to the boot sector (track zero on the drive for CP/M).  I had another 360K floppy already serviced and ready to go so I decided to use that instead of doing further troubleshooting on the faulty drive.  The drive formerly known as A will go into storage for a future repair.

For now, the replacement TEAC drive is working well as the A drive and the old Kaypro drive is back as the B drive once again.  I got all the jumpers and termination setup correctly and the Kaypro 1 is able to make its own boot disks once again...

This machine came with some cool accessories including a canvas carrying bag a desktop stand and ALOT of software on floppy disks (over 100 disks).  The next order of business for me on this project is to go through and try to figure out what software I've got...

This software is quite an exciting addition to the collection since previously I've only had a handful of disks of the software I was able to find on the Internet.  Thanks again to the previous owner of this system for sending it along, I know it will bring alot more hours of enjoyment.

TRS-80 Model 1 - Trash to Treasure - Part 1

Due to the generosity of another member of the Vintage Computer Forums I was recently able to re-home a TRS-80 Model 1 (With 16K RAM and the Level II Basic Upgrade).  The machine had come from a smoking home, but it hardly had a smell any more.  Unfortunately it did have a coating of yellow sticky tar over the entire surface, so the grey pained areas look gold instead of silver...

When I first got the unit and before I even brought it in the house I did a bit of scrubbing with water and a microfiber cloth.  With a bit of effort and lots of water the tar layer came off, so I was hopeful that a more thorough submersion with dish soap warm water and scrubbing I'd be able to bring it into a condition that I wouldn't mind touching.  Since the computer is painted, I felt that using Isopropyl Alcohol for cleaning on the outside would be too risky.  I took both the keyboard and the monitor completely apart and washed all the plastic parts with water, including removing and cleaning each keycap individually.  When I had the computer apart I rinsed the circuit boards with 99% Isopropyl and did an inspection of the circuit boards.  There were no bulging caps and nothing obviously wrong.  After putting the computer back together it looks alot better...

The silver portions look silver once again but you may notice that some the paint on the black parts of the plastic has thinned out quite a bit.  I didn't use any abrasives but the textured areas seem to have been stripped a bit even with only using dish soap.  I was pretty sure this would not be a museum piece when I started so even with these defects I'm happy with how the system has turned out.  Perhaps I will come back and use some car cleaning chemicals to try to restore some of these plastics, a trick that I've seen Adrian Black using.

The next order of business was the keyboard.  I was excited to learn that the key switches were from Alps.  The amazing key feel of these retro computers is a bit part of the appeal of these machines for me.  However the Level II machines are know to have keyboard problems and this one is no exception as most of the key switches didn't work.  This mirrored a problem I'd had with my Apple II Plus restoration, and because of the film on the surface of the machine and the dust inside I was not too worried about it.  When I had the computer apart I cleaned the keyboard deck w/ 99% Isopropyl and sprayed DeOxit into every keyswitch actuating each switch about a dozen times to start.  After waiting for things to dry I tested each key and most of them were working again with only 6 or 8 requiring a second application of DeOxit and a few dozen more actuations on each switch.  After probably about 100 actuations I finally gave up on the F key.  I had Alps keyswitches in my stock because I'd purchased some spares for the Apple II Plus repair, so I was able to use those parts.  Although, the TRS-80 uses Short Stem Switches which are more expensive and rare, so it was easier for me to take the non working switch apart and swap the stems since I only needed one.  After soldering in the F key the entire keyboard is working and I was finally able to write my first 10 PRINT program on this machine, always a happy milestone in these retro computing restoration!

More to come on this project.  I don't have the cable for the Cassette player, so I can't even use the computer to play programs in over the headphone port yet, but I have one on order and I'll be bringing the machine back out for some gaming fun when that arrives.

I'm very happy to have an example of one of the original 1977 "Trinity" of home computers.  This is the first one I've had, my Apple II Plus and a Commodore PET 4016 are the closest I'd gotten so far.  Do you have memories of using the TRS-80 Model 1?  Do you have suggestions for games or programs I should triy out when I get my cassette cable?  Let me know in the comments below, or my email address is in my Bio and you can reach me via email.

Nabu - Glad to be on the Bandwagon!

Recently I was happy to be among those who purchased a Nabu computer listed by the seller PellMill Inc on eBay.  I'd missed out on the first round after the video from Adrian's Digital Basement, telling myself that it would be a long time till anyone would be able to reverse engineer the product enough to load code on it.  How wrong I was!  Within a couple of weeks of the video coming out, DJ Sures and the team at The Nabu RetroNET had code up on their website that would allow a modern computer to emulate the network adapter and feed software to the Nabu PC.  Once I found out about this I regretted not purchasing a machine at first and I took the opportunity when the next batch of machines was released.

While I was waiting for my Nabu to arrive I watched videos and did some reading up on this computer.  I was able to buy the USB to RS422 adapter and solder up an adapter cable using 9 Pin D-Sub connectors I had on hand, and 5 Pin DIN connectors (DigiKey Part Number CP-1050-ND) that I'd purchased for another project.  I purchased the Dtech adapter recommended on nabu.ca, but I don't like the look of the screw terminal connector so I soldered both ends of the cable and got a nicer looking cable.

Getting the software going was a bit more of a challenge.  I used the PC based version of the application to get started.  This was actually quite simple and it worked out of the box the first time...

What I really wanted too have is a Raspberry Pi based solution so that I could permanently pair with the Nabu and have a functioning stand alone solution, just like the Nabu would have had back in the day.  Aaron at the Retro Hack Shack has a video showing how he did this which was inspiring.  It turns out that the software team has made some significant improvements in the Linux version and Mono is no longer a dependency, meaning that this can run from the "lite" version of a Raspberry Pi, and so it's easier to run this on a lower power Pi.  This is quite helpful because of how hard it has been to get Pis.  I was fortunate to find an RPi 3A+ unit from Microcenter back in December 2022.  This model doesn't have alot of RAM, so it's a good match for the lite version of Raspbian, and ends up being a good match for the proeject with a the compact size but also a full sized usb port for the Serial Dongle to plug into...

This solution create a nice clean solution which can easily be mounted behind the Nabu, and I can remote in to the Pi (via ssh) from any modern computer to run the text based console app that is handy in order to change to a different software cycle.

I'm excited about learning more from my hands on experiences with the Nabu.  I've already moved it out to the main entertainment center...

It's great been alot of fun playing DigDug and other 8-bit classics on the flat panel TV.  The Nabu fits in quite well with the "mostly" black look of my entertainment center, it truly was a product ahead of its time both in both form and function.

I Can't Be-leive it!

I've been wanting to run BeOS for quite some time.  I've made numerous attempts over the last couple of years ever since learning that my Power Macintosh 8600 is on the hardware compatibility list for this OS, but I've always had it lock up on boot up, or very shortly after during the install process.

I could not resolve my issue(s), I didn't know if it was due to a hardware problem with my Power Mac's Logic Board, an incompatibility with the upgraded ATI Rage video card I had in there or some other problem.  Also, I had some concerns about the stability of the machine, I'd even done a recap on the main logic board.  So, the project remained on the back burner for quite some time.

But I recently got re-inspired because Sean from Action Retro was willing to go to great lengths to get BeOS running on his TAM (and show the failures along the way).  Sean has used various disk imaging hacks before to get software onto his computers.  Because of limitations of SCSI2SD, I'd been trying to run the install process of BeOS and this was what kept on locking up on my computer.  I decided to make a couple of hardware changes.  First, I went back to the built in Video on the motherboard, I wanted to eliminate any potential incompatibility with the ATI video card.

Watching one video alone was not be enough information to get going, but Sean pointed to a rollicking good thread about running BeOS on the TAM on Tinker Different.  This thread contains a helpful link onto Macintosh Garden that has BeOS disk images that are useable with compatible machines, bypassing the install process.  All one needs to do is copy them onto a modern SCSI to SD solution and give BeOS a try!  In order to enable using these pre-made disk images, it was time to upgrade my SCSI2SD solution.  As amazing as that tech was when I installed it in 2018, solutions like BlueSCSI and ZuluSCSI are much easier to work with on projects like this.

One other cosmetic improvement that I have been wanting to make is to move the SD card slot around to the back of the machine and replace the front cover on the machine (which of course I've kept) so I took this opportunity to make this change as well.

Of course I didn't want to loose access to the MacOS disk images I've built up over the last years.  Another interesting post on TinkerDifferent lead me to this amazing tool called Disk Jockey.  This software runs on the modern computer and allows the analysis of disk images.  I was easily able to create a disc image of the Mac Volume on the SCSI2SD card(s) and then convert them to full drive images for the modern SCSI solutions so the PowerMac can still boot the first and last versions of Mac OS (7.5.5 and 9.1) was well as BeOS.  I've stored these each on a separate SD card for easy of swapping.

It's really great to finally have a BeOS system, and I'm quite happy with how it looks...

I've really been enjoying tinkering with it.  The history of Apple's negotiations with both Be and with NeXT for their "next generation" version of MacOS are now the stuff of computer history legends.  I consider myself lucky to be able to go back and see the best of what both OSes had to offer at the time.

NextStation Online!

2023 is turning out to be a year where I close off loose ends with my Retro Computing hobby.  I've been acquiring hardware at a pretty good clip over the last couple of years and I've been thinking about things I could do with the equipment but just seem to never get around to.  And so far this year I am getting around to quite a few things.

Taking inspiration from both Macintosh Librarian and Sean @ Action Retro, I recently came back to my NextStation.  I've talked about acquiring that machine previously on the blog, and I've had it for over 2 years now.  Although I do keep coming back to it this computer has provided a challenge for me.

As we all probably know NextStep OS was the forerunner of our modern MacOS, but it's old enough that although it does have some familiar apps and look and feel, it's also quite different from modern MacOS.  As an additional challenge, I'm not that strong with Unix but the version of Unix that underlies NextStep OS is quite dated and so many of the commands I'd expect from Ubuntu or Raspbian  are simply not there, leaving me with alot of reading and Googling to do in order to use the system.

I decided one way to get a jump on this was to install a Next emulator on my modern PC.  That was a bit of an adventure and I found a shortcut that may be helpful to other people which I will document here.

Ctrl-Alt-Reese has documented the process of getting NextStep installed on actual hardware, but he also called out a link on WinWorld that contains a pre-setup copy of the Previous emulator, a Hard Drive image, and the required ROMS.  This version of the emulator is quite out of date so even if you are running Windows on your modern computer, I'd recommend going to the Previous hompage and getting the latest version (2.6 as of this writing).  Once you have all these components installed together it's fairly easy to configure the modern version of the emulator to point at the ROMs and the existing Hard Drive image from WinWorld.  That being said, getting the emulator running was not that big of a help to me because the biggest hurdle was getting my NextStation connected to Ethernet networking, and that's quite a bit of a different process inside of the Emulator.

So, I was back on my actual black hardware.  Following along with Sean's video above we see that we have to set a Static IP on the NextStation.  I was able to do this using some help from the manual section called "Setting Up the NEXTSTEP Computers" in this linked document.  This doesn't cover the DNS issue that Sean shows, so I also did that step.  Oddly enough, after rebooting, I was not able to ping like Sean was (I suppose it is not on the path, but I don't know what directory it should be in).  But when I went over to another computer I was able to Ping the NextStation so it was up on the network.

The FTP command did work, thankfully, and I was able to connect to my NAS where I store software for my vintage computers and grab some files and pull them over to the NextStation, uncompress them and install them.

I also figured out which folder to load software into (/LocalApps/) so that it can be easily added to the Dock and executed by normal users (not root), so now I have Mathematica, Doom, and OmniWeb installed and configured on my NextStation, and an easy workflow to add more software at any time.

I consider myself fortunate to be the current owner of this hardware and will be able to get a great deal more enjoyment from it now that I know better how to use it.

Starting the New Year with a New-to-me Retro Computer

 Happy New Year, everyone!  I hope you've all had some time off and some rest.  I was able to get alot of small projects done during the break, and I've tried to "clear the decks" a bit to start 2023 on a good footing.

One of the opportunities that came my way in December was finding a couple of people who were purging TI 99 4/A Computers.  I also have not had alot of interest in these machines until I started watching a YouTube Channel called Usagi Electric.  The TI-99 scratches a couple of itches for me.  One of them is my interest in engineering / business failures, or the "Might have beens" of technology development, and the others is my interest in Mini Computers.  I didn't realize it until Usagi mentioned the history that the TI Microprocessor used in this machine was based on their minicomputer architecture.  The rise and fall of TI and their battles with Commodore are one of the more interesting chapters in the early history of the home computer.

Anyway, I was able to get a couple of bundles of unwanted TI-99/4As, four machines in total.  One was working and three were not.  Having a working machine is always a big help and I started watching videos and swapping parts.  Noel's Retro Lab and Adrian's Digital Basement both have helpful series on this machine, although I must confess that I haven't done any board-level troubleshooting yet. I was able to get three of the four systems working and the fourth one has so many things wrong with it that I'm not sure it will be worth repair, I may just keep this as a parts machine for the others.

One of the running machines has an Alps keyboard, so even though it's not the most pristine of the cases I am a bit of keyboard snob and so likely this one will become my favorite TI-99 4A...

I've paired it with a small RCA color TV, model XL100 from 1987.  The image isn't great, perhaps because the tube in this TV is getting tired or because the image is going through an RF modulator.  One of my next steps for this machine is to built a Composite video cable for it so I can use it with a more modern display, I have the parts on order for that from Digikey.  Thanks to Adrian I now know that it's the same cable as the one for a C64 or Vic-20, so I will build a couple of these.

Leave a comment or send me an email if you have any interesting memories of the TI-99/4A!