MARK 8 Vintage Computer

Bugbooks

Radio Electroics Magazine July 1974

Here are five MARK8 computers all very different in the construction. These MARK-8's are in our Bugbook Microcomputer collection.

The MARK 8 computers are all very unique - some made by people skilled to do a very good work and some inexperienced in building electronic devices.

You will see a real variety in the construction of the 5 MARK 8 computers in our collection.

Click on photo's to enlarge

MARK8 Computer

MARK8 #1    This is most likely the most complete and complex use of the MARK8 cards ever. Of course I don't know for sure and would like to hear from others about there knowledge of MARK8 Computers.

I can not imagine how many hours went into building and testing this computer. It was built for a specific use with many special cards. I have been researching for information about this computer and sent an email to WA4GVT- you will see in the next photo his amateur radio call letters are on the top front of the computer. I just received this reply today 5-5-14. Hi, Guilty as charged !! BUT with one exception, we owned that machine for a lot of years but I did not personally construct it. We were in the process of building one when this fell in our lap. I will try very hard to remember who I got it from and will let you know asap. Would love to see ur Museum some day and see some of the treasures there.
Perhaps we will find out who actually built this machine.

MARK8 Computer

The front panel looks like it is operator friendly - with numbered keys to operate the computer and not the toggle switch register on the other Mark 8 computers.  The builder must have written a lot of code for the machine including a custom BIOS operating program -- just for the front panel.

MARK8 CPU card 8008 microprocessor

The simple wire bus that John Titus used was directed to this add on board for a real computer bus system. All the cards plugged into this bus. The card here is the 8008 CPU card.

Bus extender card for trouble shooting

A bus extender card came with the computer to ease the trouble shooting of various boards and software.

MARK8 Computer

The computer is self contained with some custom cards and power supply built in.

MARK8 Computer

I would like to know what the computer was used for as it has  a lot of I/O connectors on the back side.





                  
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Original Mark 8 Computer 

MARK 8 #2
This a very good example of a all the MARK 8 cards assembled into the basic MARK 8.  To have a working computer you had to add power supply, a case, and some way to enter data into the computer and execute programs.

Original Mark 8 Computer 

 A switch register front panel ( You see this in computer #4) was the simple approach.  You could add a serial interface and with software driver and use a teletype or other serial terminal to operate the computer.

This computer is on display in our "Bugbook Historical Microcomputer Museum" in Floyd Virginia.



     
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              Click on photo's to enlarge 

MARK8 Computer

MARK 8 #3 This is an exact copy of John Titus's computer on display in the Smithsonian Museum.
The computer was built by Roy Justus of Christiansburg, Virginia. Roy was a student in my 'Electronics for Scientist' course at Virginia Tech in about 1973. Roy called me one day in 2007 and told me about the MARK8 he had built and would like me to have it in our "Bugbook Computer Museum. I felt very privileged to have this opportunity of such a fine gift. Needless to say when I viewed the computer I was really amazed at the great detailed construction Roy had done on the project.

MARK8 Computer

Roy did not purchase these cards from the vendor John Titus used in his 1974 Radio Electronics article. Roy made the cards himself from the layouts furnished with the construction book you could purchase for about $5 at the time the article came out in 1974.  The boards and the wiring are a first class job -- take a look up close and see he even put strain releaf shrink wrap on each connection.

MARK8 Computer

This is a working computer with an excellent manual of about 50 pages Roy wrote just for this project.

I am very proud to have this MARK 8 computer on display in our "Bugbook Historical Microcomputer Museum. The museum is located in downtown the Village Green in downtown Floyd Virginia. Come on by and take a look-- if you can't maybe my audio tour will be a help "CLICK".       THANK YOU  Roy Justus for this wonderful contribution to the museum.

We are using QR codes in our museum with audio description for each display case. If you would like to test and see -- here is what you get by clicking on the QR code with a smart phone -- this is display case #8 with the Roy Justus computer - click on photo to enlarge while hearing the audio tour to this cabinet. "CLICK to hear test"

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MARK8 Computer

MARK8 #4 This MARK 8 computer was built by George Overfelt in 1975.  Very nice constuction of the basic computer with power supply, front panel and serial interface built in.

This MARK 8 is on loan to the "Mid-Atlantic Retro Computing Hobbyist"  - 'MARCH'  group and is on display in their museum.

A video tour of this computer "CLICK"

MARK8 Computer

When I received the computer in the late 80's it was still operational.







Here is a telephone conversation with George Overfelt about the MARK 8 and other computer topics 8-15-13 - Nice that George is still active at his age - We chat now and then by phone about this MARK 8 computer he built 38 years ago in 1976 - This added 8-15-13 

I think you will enjoy this conversion with George he tells his experience building the MARK8 and with other early computers.
Here is one of my first interviews 1-28-13 with George Overfelt 25 years after we acquired the MARK8 from him. Added here 8-22-13

MARK8 Computer

George did a nice job of wiring . He was a professional electronics person.

MARK8 Computer

You can see the power supple as it was built below the computer in the case.




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MARK8 Computer

MARK8 #5
This MARK8 is a good example of how hobbyist were willing to try building their own computer. A minicomputer was the only alternative in 1974 and these cost thousands of dollars - most hobbyist could not make this kind of expensive purchase -- the MARK8 gave them an opportunity to build a computer for less then $1000.

MARK8 Computer

I don't know if this computer ever worked but the builder put a lot of work into this project. It is rather crude in the packaging and the switch register on the front.

MARK8 Computer

The rack holding the cards in fiber board and it is now starting to disintegrate. Real wood would have lasted just fine.

I have to give the builder credit for really putting a lot of work into having his own computer - I hope it worked for him.

MARK8 memory board

Molex type connectors were used for the integrated circuit sockets and these are well known to fail often.

MARK8 Computer

I do not know what the blue card is -- it is  not a standard MARK8 card. Looks like the builder had some skills to use this card.






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Other MARK-8 computers "CLICK"
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Terry Ritter tells his experience building a MARK8 in 1974 - It was a lot of work to get one into operating condition - interesting story.


The MARK 8 was available as a construction article in Radio Electronics July 1974.  John Titus designed this computer to satisfy his desire to have a computer of his own. This was the first time detail instructions were available to build a microcomputer using a microprocessor chip - the Intel 8008.  Several hundred sets of boards were sold however you had to gather the parts on you own to assemble the computer.  Not many were actually assembled and even less were made operational.  Perhaps less 50  exist today.  We are fortunate to have 5 in the "Bugbook Historical Microcomputer Museum" collection .

These 5 MARK 8 computers are a result of many years of collecting. I remember in the mid 80's I had given away my MARK8 computers and started to look into adding one back into  the collection and over the last 26 years have  been very fortunate to gather these 5.  The 5 are an eclectic group all very different. Two are in our museum, one at MARCH and 2 still have their life in our Bugbook museum warehouse.

  

   ^{"by David Larsen"  KK4WW Computer Collector Historian}     Send Message    Like us on Facebook  My Blog about hometown Floyd VA

Microcomputer - Micro-Designer MD-80 one of the first complete educational / design Microcomputer Systems

      John Titus tells about his designing the MD 80 microcomputer in the mid 70's

The Micro Designer 8080 (MD 80) microcomputer was the first system for training & development commercially available.  The system was a complete operational microcomputer with all the input/output signals easily available as solderless connections, training material  , and many operational software examples.

MD-80 by Blacksburg Group

 
   David tells little story about the origin of the very first complete training microcomputer

Dr. John Titus

This was the second major computer design for John Titus.  His first design "The Mark 8" computer was published in Radio Electronics (July 1974)  as a graduate student at Virginia Tech. The Mark 8 was also a milestone computer as one of the first constructions articles that made it possible for a computer geek to make his own affordable computer. This was 2 years before the Steve Wozniak's Apple 1. Here is the MMD-1 our second commercial computer and the first single board computer - another history maker for John.

MD-80 Micro designer

These were very exciting times for the group at Tychon blazing and leading the frontier in digital and microcomputer education. The group consisted of  Dr. John Titus , Dr. Peter Rony, David Larsen and later Dr. Chris Titus.

MD1 teaching in 1977

WOW I just found this 1976 slide using the MMD1 wired to an experiment when teaching an Interfacing Workshop.

MD-1

E and L Instruments Catalog

MD-1

Solderless breadboard Bus signals

The computer and educational material was marketed by E & L Instruments in Derby Connecticut.  I had arranged an agreement with E & L a year or so earlier to market the basic digital training system consisting of Bugbooks 1 & 2 along with digital training aids known as "Outboards".  This was about 38 years ago in 1975 and I remember my meetings with the E & L president Mr. Murry Gallent. This contractual arrangement provided our group had a nice royalty stream for about 10 years with many other books and hardware. The Group soon became known as the "Blacksburg Group".  E & L Instruments published the original Bugbooks . Fortunately we kept all the rights to the books and about a year later our publisher was "Howard W. Sams" and the books were known as "The Blacksburg Continuing Education Series"

See Micro- Designer computer (red) in the header on this blog - right side behind the word Museum.

David Larsen KK4WW

 The 10 years our group was creating books, microcomputers and digital training devices was a great experience for us. The 10 year path took many turns and most were positive and upward. We did have few bumps along the way.  One time E & L stopped paying royalties and were had an interesting and expensive lesson about litigation. Other than the cost of attorneys the royalties resumed from E & L.

^{"By David Larsen" KK4WW Computer Collector Historian}   
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MMD-1 Vintage 8080 Microcomputer reported to be the First Single Board Computer

 The first single board computer - MMD1
Click on photos to enlarge

Original Prototype MMD1

 The Microcomputer Trainer MMD -1 designed by John Titus is in the Wikipedia listing for Single Board Computers as the first single board microcomputer.

Production Model

We originally called the computer "Dyna -Micro" and the the production units were called "MMD1" - that was just short for 'Mini Micro Designer'. The Wikipedia listing for the single board computer does not mention John Titus as the designer - it does mention the computer was made popular by  Bugbooks. Bugbooks 5 and 6  used with this computer. An
original prototype is on display in our "Bugbook Historical Microcomputer Museum".


John Titus tells in his own words the development of the MMD-1 computer

 The second item about the microcomputer pioneering work by John Titus ----

Dr. John Titus

The  MARK8 computer construction article published in the July 1974 Radio Electronics  by John Titus was a Milestone for the magazine in the computer revolution. According to Wikipedia - Radio-Electronics featured audio, radio, television and computer technology. The most notable articles were the TV Typewriter (September 1973)^[1] and the Mark-8 computer (July 1974).^[2] These two issues are considered milestones in the home computer revolution.^[3]

^{Here is where you can get a real good view of John's 'MARK8' work - this was put together by authors at Florida Gulf Coast University and was copyright 2007.}   

Here are some really nice comments John made about our work together more than 35 years ago.

Me - David

 It has always been a great pleasure for me to be a colleague of Dr. John Titus. The work we did together in the 'Blacksburg Group' 38 years ago was a real highlight in my electronics and computer journey. John is retired and living in Utah near family. Thank you John for the memories.
^{"By David Larsen" KK4WW Computer Collector Historian}  
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Vintage Computer Collector Memorabilia - Titus 8080 Microprocessor Slide Rule

                                                                                                                               

Museum Bugs

Vintage computer collecting for many collectors includes many different types memorabilia in addition to vintage computers.  Popular memorabilia include such items as advertising posters, outdoor signs furnished to attract customers, sales counter displays, T-shirts with logo, aids used in programming, original manuals/data sheets, interesting photos, counter displays, magazines, news letters, programming aids -- the list does not end.
                                                      
I have mentioned in the past my colleague Dr. 

John Titus 8080 octal code card 

 John Titus was very creative designer. One of his many creative designs was an 8080 microprocessor  programming aid the "8080 Octal Code Card" slide rule. This  was extremely useful aid for programming the 8080 at the assembly level or in pure machine code.  This was marketed for a few years in the late 70's & I doubt if many still exist. This is a great collectable memorabilia for computer retro geeks.I show how this is used and give a little demonstration in the video.

Update 11-27-15 I still have some of these cards - just contact me if you would like one. 
Just located a group of 50 of these in our Bugbook Computer Warehouse and they look just like the day they were made - Sharp.  I will be glad to share these with memorabilia collectors for $5 including shipping 
. Contact me here.                                       

                         

One of my reasons for writing about  the 8080 slide rule to point out the use of our Bug's.  The bugs were part of our "Blacksburg Group" branding effort more than 40 years.  I still use them to help identify and connect my present work to the "Blacksburg Group" which I was a part of during its 10 years of operation in the 70's & early 80's. I call this a slide rule because it has a slider inside and by sliding it to the proper position you had all the machine code instructions for the 8080 at in one neat package. Only the geeks that program microcomputers in machine code and being able to program one machine program step at a time really care about this.

John Titus 8080 octal code card

 The origin of how we created these bugs is an interesting story and I will tell about that in a future post. Just a hint - the integrated circuit (IC) chip of the 70's looked somewhat like a real bug.  The chip had many connecting pins making it look like a bug with many legs.

Integrated Circuit (IC) looks like Bug

Most of the designs and writing our group did was about digital electronics and the most  digital electronic circuits were contained in these IC chips. We thought it was a unique idea to have some original characture bugs as a branding logo. The first use of the bugs was with Bugbooks I & II  just before we formed the "Blacksburg Group. These Bugs were on literally on several million products. The "Blacksburg Continuing Education" books series by itself has more than a million in print. They have been out of print for more than 30 years however you can still go to Amazon and find most available from used book sellers. Many have become collector items - some in new condition are selling for up to $500.  Try this - go to amazon.com book section and type in "Blacksburg Continuing Education Series Books" and check it out. I was sure surprised to see the asking price for some of the books in our old series. I guess these books are part of the vintage memorabilia I am writing about in this post. Also notice you will see the Bugs in the upper right hand corner of every book.

The bugs are currently owned by my colleague Dr. John Titus and I use them with his permission.

  Appreciate a like on Museum Facebook Page.

Chantilly Farm

David Larsen KK4WW

 People often have a  specific image such as "Professor" , "Teacher" "Amateur Radio guy" "Farmer" and in these posting if you had no other reference I would most likely be "The Computer Collector fellow".  I want to  tell about one other hat I wear is  - "Chantilly Farm"  Owned by my wife Gaynell and I. This is a 200 acre 'Festival Farm'  in the heart of the Blue Ridge Mountains in Floyd County Virginia. Chantilly farm is managed by the LCF Group and our Promotion Manager is Jason Gallimore, Jason books all the great music for Chantilly. We have other good help as well. What do we do at Chantilly Farm? Take a look here www.chantillyfarm.com . 

 Have a great week -"by David Larsen" Computer Collector/Historian