September Updates!

The last few weeks have been very busy for VCM!  We recently received a large donation of items, including some nice IBM equipment that we have been wanting for a while.  Many of the machines were beyond repair, but we were able to salvage some CPU’s and other needed parts.  We were also able to restore an IBM 5153 monitor along with a complete IBM PS/2 model 30 with model M keyboard.

Another recent project was the completion of the restoration of our beloved Commodore VIC-20.  Thanks to an ebay seller who had the side panel we needed, the VIC has now been restored to original condition and thoroughly cleaned inside and out.

We also began our CPU collection this month after going through lots of scrap motherboards and systems.  While it does not quite fit with our desire for everything to be in working order, I felt that it was both appropriate and interesting to preserve examples of CPU and coprocessors.  If for no other reason, the variety of pin configurations and size comparisons can be fascinating.

Lastly, we now have a complete working Wyse-60 green screen terminal.  This one has been on my list for a while as it is what I spent most of my college years typing on.  So, this one was a bit of a personal nostalgia on my part, but as a common alternative to popular IBM and DEC terminals, it does hold it’s own in the history of serial terminals.

Please explore our hardware collections for these and other updates, and as always thank you for your support!

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Commodore 1541 Disk Drive Rebuild

I recently pulled two classic Commodore 1541 disk drives from storage to check their condition and serviceability.  Both drives had sustained physical damage falling from a storage shelf several years ago.  Even before that, their condition was unknown.  Upon closer inspection, I found that the drives had both impacted the floor face-down, meaning that there were some cracks and bent metal parts internally on each of the drive mechanisms.  There were also some cracks in the plastic enclosures.  I decided that the best approach was to consider taking the best parts from both to build one working unit.

The first step was to disassemble both units and select the mechanism and outside shell halves with the least damage.  Luckily, one of each of the top and bottom shells were undamaged so we have a complete enclosure with no cracks.  I chose the better of the two mechanisms, swapped some mechanical parts and straightened some minor bends to get a mechanism that opens and closes smoothly.  The photo below shows a close up of the damaged area, unfortunately both bezels were cracked, so I chose the best of the two.

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Once the head was cleaned, the mechanism was mounted and I moved on to the electronics.  Both drives had already been tested for working power supplies, so there were no worries there.  As for the controller board, not knowing anything about the condition, and given that there were no obvious physical defects, I chose to start with the newest of the two.  One board appeared to be an older revision, so I opted for the newer one.  After connecting the controller, it was time for the initial testing.  Surprisingly, the drive powered on and appeared to pass the self test so I pulled out the trusty VIC-20 and connected it up.  Unfortunately, powering on the computer did not trigger the typical reset on the drive.  However, I went ahead and tried to load a directory but was soon greeted with a flashing red light.

Figuring that the lack of reset involved communications circuits between the computer and drive, I tested with a known good 1571 as well as with a known good C-128 since it has been a long time since we had the VIC-20 connected to any disk drives, but all that did was prove that the 1541 was the source of the communications problem.  Before pulling chips, I tried swapping the entire controller board, but that did not lead to a working drive.  So, on we go to swapping chips, starting with the 6522 VIA closest to the serial ports.  After several back and fourth swaps I was able to isolate one bad 6522 between the two boards.  Although the reset routines were now working properly, the drive would still not read a directory, leading to some head chattering and eventually erroring out.  It also appeared that the newer controller board may have some other issues as well, so I stuck with the older controller with known good 6522’s which provided a consistent experience other than the read errors.

After reading some other posts, since this is the Newtronics mechanism, the likelihood of a bad head seemed pretty high.  Since it was easy to do the basic ohmmeter test, I went ahead and did that and was surprised to find that pin one on the head was showing open.  So, back to the other mechanism that had already been scavenged, I tested that head with the ohmmeter and found that it tested just fine.  So, after some more surgery to extract the working head, followed by thorough cleaning, it was swapped out.

Here is the complete mechanism with the transplanted head:

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So, let’s test again…

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Success!!

So, the head was indeed bad.  Now for some more complete testing, I went ahead with a full format, as well as to test this newly formatted disk on another known good drive to make sure there was no major alignment issues.  After several back and forth rounds I was happy with the performance, enough to go ahead and put everything back together.

Finished drive:

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So, 2 damaged 1541’s become one working unit, proving again just how rugged these units were.  Beyond the physical damage to the plastic and mechanisms, one of the heads was bad, and one 6522 was bad:

Photo-2016-08-11-00-03-15_7112

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Initial documentation of hardware collections now complete!

After many years of work, we have completed the initial catalog of all hardware systems currently in our collections.  Each system has at least one photo and basic description information included.  Working systems have photos showing screenshots or other documentation of their condition.  We will continue to improve each page as systems are restored, displayed, tested, or otherwise worked on.  We will also continue to add software titles and publications to the collection as time permits.  Any new systems that are acquired in the future will be added promptly.  Thank you for visiting our site, we hope that you enjoy seeing these iconic systems in action!

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Tandy 6000 restoration underway!

Restoration of Tandy 6000 Xenix system circa 1984 is now underway.  Follow our progress on the Tandy 6000 page.  If you have expertise and/or parts available that you would like to contribute, please contact us.  Thanks!

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VCM Collections used for local vintage computer event

We were pleased to have the opportunity to provide some elements from our collections to a local organization to be used for an in-house event.  This was the first time we have been able to get our collections out in front of the public for some hands-on viewing.  The event was a great success, and we look forward to future opportunities to provide our collections for public viewing.  Some photos are below:

photo 1

Setting up

photo 2

Game console area

photo 3

Artifacts on display

 

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Hardware collections updated

Over the past couple of weeks we have started to add additional systems to the hardware collections, and updated some of the existing items with condition information.  We are excited that many of our systems have been tested and found working, or have recently been repaired.  Some of the interesting repairs include the VIC20 and NEC portable computer.  It was also exciting to see the Commodore PC-10 complete POST for the first time.

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Updated site for 2015!

It’s been a while, but we have updated our site for the new year.  The new site will be more mobile-friendly and some new collections content will be added in the coming days.  Thanks for visiting the site, and check back often as we work to fully document all of our collections.

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Software collections begin

Began development of software collections with Atari 2600 Software listings.

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Hardware collections begin

Commonwealth Technical Services, Inc.  leases storage space for the VCM for initial collections.  Photos of IBM System/32 and other artifacts are added to the collections area on the web site.

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Virginia Computer Museum Website Launched

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