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Commodore PET 30th Anniversary

June 2007: Footage from the Vintage Computer Festival East. Chuck Peddle speaks on the PET 2001 (Click for larger image)

There is an article in the October 1977 issue of Byte Magazine about the National Computer Conference in Dallas, TX June 13-16 describing all of the new computers and manufacturers' wares . Included in the article, on page 54, is a picture of a prototype PET 2001 from the event. Even earlier photos exist from the January 18-20 Gametronics Convention. To my knowledge the Gametronics photo is the first public display of a PET. Note the different front name plate.
Compare that photo with the image above and this photo, of a early production PET 2001-8 with the classic blue face plate and monitor. ...Comments?

30 years after the Dallas convention, Chuck Peddle helped commemorate the occasion by speaking at the Vintage Computer Festival East 2007 via Skype video conference. Mr Peddle shared his recollections of how the KIM and PET came to be and described the early days of Commodore computers. Chuck detailed the relationships between Commodore, Microsoft, Apple, CP/M, Bill Gates, BASIC, MOS, and the early computer fairs.

Following the video conference, a panel discussion about later Commodore history included former Commodore / Amiga engineers Bil Herd, Bob Russell, and Dave Haynie. These gentlemen brought with them some prototype boards and rare computers from the mid to late 1980s.

Bob Russell, Bil Herd, Evan Koblentz (MARCH pres.), and Dave Haynie holding the Commodore PET 30th birthday cake.

Commodore Prototype Photos from VCF East 2007

The only known Commodore LCD laptop

Commodore LCD laptop, cover open
Commodore LCD laptop, rear ports
Commodore LCD laptop, side left ports
Commodore LCD laptop, side right ports
Commodore LCD laptop, top view

Commodore 264

Commodore 128 Motherboard Prototype
Various Shop prototype boards

More pics from the VCF Exhibits

Commodore Midwest Regional Staff Newsletter Archives

Recently I received a stack of old newsletters from the Commodore Midwest Regional Staff. These were sent to the service technicians. Please contact me if you'd like more information/copies. Here are a few interesting tidbits.

Make your CBM 8032 think it's a VIC 20
If you have a Commodore PET 8032 and you want to make it think that it's a VIC 20 try this:

poke41,16:poke4096,0:new [enter]

...You'll get a syntax error, but you can ignore it. Try loading a BASIC program meant for a VIC 20. It should work as long as the program has not pokes or sys calls.
Summarized from the Commodore Midwest Regional Staff Newsletter Dec 29, 1981

How to change the device number on a CBM 2031 disk drive programatically
The 2031 disk drive has a slightly different procedure for software changing of the device number. Use this short program to change it.

10 input"new device number";dn
20 open15,8,15:print#15,"m-w"chr$(119)chr$(0)chr$(2)chr$(dn+32)chr$(dn+64)

...where "new device number" = 8,9,10,11,or 12 depending on what you want to change it to.
From the Commodore Midwest Regional Staff Newsletter April 7, 1982

How to change the device number on a CBM 2031 disk drive permanently
Near the middle of the 2031 circuit board there are two diodes marked cr18 and cr19. By removing these diodes in the proper order, you have several device number choices.

device num

From the Commodore Midwest Regional Staff Newsletter April 22, 1982

Copying files to a CBM 2031 from an 8050 (or any drive)
"..the 2031, unlike the other Commodore drives, sends a reset on the IEEE bus when it is turned on. This resets all devices to their default device numbers. Thus, if you have changed the device number of the 8050 (or other drive) programatically, turning on the 2031 sets the 8050 back to device 8. The solution is simple: just be sure the IEEE cable is not attached when you turn on the 2031..." This will isolate the target drive from the bus reset, and leave the drive number as you set it.
Summarized from the Commodore Midwest Regional Staff Newsletter April 15, 1982

Commodore 4096?
"The 64K memory expansion board that converts the 8032 into an 8096 will also operate on the "FAT 40" 4032. The operation is the same as on the 8096." Purchase NOS expansion kits here!
Summarized from the Commodore Midwest Regional Staff Newsletter April 15, 1982

New History of CP/M Web Site

A new web page by Herb Johnson was published this month to document the important points regarding the developmental history of CP/M and Digital Research Inc. CP/M is an operating system originally written for the Intel 8080 processor in the mid 70's, further popularized on Z-80 systems. Herb has posted his research on his web site, retrotechnology.com.

Using Toggle Switches to Analyze Memory

Wondering how to read memory using toggle switches on an old Altair computer? Do you have an IMSAI or Cromemco but don't know how to load a bootstrap program into memory? Do you want to test a system to see if it's working correctly? Perhaps I can get you started. At the Vintage Computer Festival East I gave a talk titled "Vintage Computer Hardware 101 Featuring the MITS Altair 680b" You can download the Power Point presentation here.

Comments / Questions?

More Pics from VCF E 2007

Click Image for larger versions


An Ohio Scientific 2P

Past Issues:

On the Work Bench - Jun/July 2007

These are some of the computers and things that I am currently working on, or have recently picked up. Check my Vintage Computer Blog for updates, or post your questions.

Lobo MAX 80

Click Image for larger version

When you first power up a MAX 80, it responds by sending out a short beep every few seconds. That's the system telling you it needs a boot disk. If you plug the computer into a monitor, you'll only see a bunch of garbled characters...this is normal although not necessarily enough to inspire confidence when you have no boot disk to test with. And for two years, that's as far as I could get. I had been attempting to boot the system with a disk I found labeled "MAX-80 BIOS" on a Lobo twin 8" disk drive, but I had no idea if the disk was a system disk or just plain bad. I did not have a lot of confidence in the drive either. Every once in a while I would pull the system off the shelf, hook up a new combination of cables or drives or disks to see if I could make progress. No luck.

"LDOS 5.1.3 v. MAX513" Click Image for larger version

The big breakthrough came when I finally acquired another Lobo MAX 80, this time with some diskettes. Taking a known-working 5 1/4" Percom disk drive and the disks from the new Max 80, I was able to boot the LDOS 5.1 disk pictured above. I could then check file directories, etc. I was able to locate the program file needed to load Lazy Writer v 3.4. Unfortunately the Lobo CP/M disk that came with the system did not boot. I was also able to duplicate the process on my original MAX 80, so now I have two working units.


Exatron Stringy Floppy

Click Image for larger version

The Exatron Stingy Floppy was introduced in April 1979 at the Computer Faire in San Francisco USA. According to the original order form (in my possession), a person could purchase a Stringy Floppy drive for either the a TRS 80, SWTPc or S-100 system. No SF was ever made for an S-100 (I assume equipped with a Z-80 processor), but there were some SWTPc 6800 users according to their newsletter. To date none have turned up that I know of making this a very rare item if you can find one.

At the time the SF offered an improvement over cassette storage, but reliability was a problem and the drives met only limited popularity. Eventually diskette drives became less expensive and both the cassette and SF fell out of favor.

The Stringy Floppy Wafers are 2 11/16" x 1 9/16" and they function similar to that of cassettes, except that they're on a continuous loop, no rewinding is needed.

Snapshot of the initialization process on a TRS 80 Model 1

A close up view of the drive belt. Click Image for larger version

At first I was able to engage the system, format a wafer, load programs, and save files using the SF with a TRS 80. Just before the Vintage Computer Festival East 2007 the drive belt snapped! I attempted to roll my own belt using a latex band. The results were inconsistent. You can see in the picture above a closeup of an intact drive belt. The belt powers the spindle that moves the "string" past the read head, and that's the only moving part in the drive. I tracked down Robert Howell, the inventor of the Stringy Floppy, and asked him if he had a drive belt in a drawer someplace. He laughed and said he long ago did away with that stuff. We also discussed the history of the Stringy Floppy drive and how it all came about. I will write more on this subject soon.

Fortunately I was able to get another SF drive and I am in the process of converting wafers to cassette and/or disk. I will post the results in the blog section. More SF info here

Classic Computing Items for Sale:

CBM Commodore B Series Software
(B-128 / CBM 700)
Superscript II Word Processor$29.99
Superbase Database Manager$29.99
Commodore Advanced Business Systems (CABS) Acccounting Suite: Accounts Payable, Order Entry, Accounts Receivable, General Ledger (4 binders)$29.99
More CBM Commodore Items
Commodore B-128/700 Programmer's Reference Guide - Protecto - Everything you need to know about the B line!SOLD OUT
B Series Commodore Users Guide - View Image$39.99
Commodore Users Guide Series 8000$39.99
Commodore BASIC Users Refence Manual Version 4.0SOLD OUT
Commodore CBM Expansion Memory Board 64K Expansion Kit for PET 8032 (NOS)SOLD OUT
Commodore PET Keyboard (NOS) for 2001 -N, 3000, 4000 SeriesSOLD OUT
Other Commodore CBM Power supplies, software, parts, etc.Contact Me
Tandy Items
Aeoromp Double Density Controller for TRS 80 Model 1 Expansion Unit (NOS)- detailsSOLD OUT
Model III / Model 4 (non-gate array only) RS-232 KITS detailsSOLD OUT
Model III / Model 4 (non-gate array only) RS-232 boards onlySOLD OUT
Model III Aerocomp Diskdrive controller$39.99 (free US Ship)
Looking for Something Else?
Please check here first with special requests for Commodore, IBM, Tandy, Atari, TI, Apple computers, parts, components, and software. I have systems plus zounds of miscellaneous items for sale or trade.

History of Commodore Computers Poster $19.99
History of Commodore Computers Poster C64 C128 B128 Plus/4 PET KIM and more.

For more information about the C Prompt found at the top of each page, click here.
All photography on this web site is © VintageComputer.net/Bill Degnan and cannot be reproduced without permission.

This web site has two purposes.

For years I have been making research notes while in the process of restoring classic computer systems, and I also like to record tidbits of information that I think might be useful in the future. This web site is a way to share this information for research purposes. I will also post restoration project reports, project summaries, users guides, tutorials, and items wanted. I invite anyone who wishes to contribute their comments to the VC Blog to do so. My goal is to publish new content in the field of classic computing.

The second purpose of this web site is to sell off my duplicate items. Unless otherwise stated, all items for sale are in working order. If you wish to post items for sale on the VC Blog, please indicate clearly the operational status of the item(s).

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