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PDP 11/40 M7234 TIMING CPU Card Fail

by billdeg
Total messages in this thread: 1
PDP 11/40 TIMING module DEC 5380 SN20628N 2-input NOR removed
Closeup of a PDP 11/40 TIMING controller card, M7234 where a Dual NOR DEC 5380 SN20628N 2-input NOR chip has been removed. It caught fire. A replacement chip was pulled from donor M7234 and the card appears to be working correctly again. Click image for larger view.
Full disclosure - I accidentally plugged the M7234 into the wrong UNIBUS CPU backplane slot, ug. Too much juice to the chip fried it. Using three sets of 11/40 CPU controller cards I had been swapping cards around in the effort to get an EIS CPU card (M7238) running. The EIS is necessary to boot UNIX but I have been unsuccessful in finding a working set of">... [ read more ]

Iowa State 1957 IBM 650, Cyclone 1

by billdeg
Total messages in this thread: 1
Iowa State College Progress report No 1
Iowa State rented an IBM 650 and went live in February 1957. The implementation team published a report on their progress, lead by T. A. Bancroft Director, Statistical Laboratory; Chairman, Working Committee for the Improvement of Computational Facilities at Iowa State College
"...After much careful study, an interdepartmental "Working Committee for Improvement of Computational Facilities at Iowa State College" recomĀ­mended, early in 1956, both the rental of an IBM 650 at a 60% educational discount and the construction of a digital computer for which the llliac at the University of Illinois would serve as prototype. The IBM 650 was inĀ­stalled on February 7, 1957 and has now been in continuous service for over two years. Construction of the Cyclone, ISC'">... [ read more ]

Cromemco System Three Revisited

by billdeg
Total messages in this thread: 1
Cromemco System 3 Three Disk Drive Interface Controller
Pictured is the drive signal/power interface board installed in the chassis of the Cromemco System Three. This board is used to route power to the Persci 299 twin 8" drives, and I believe the drive controller signals. Visually inspect the board. Can you guess what's wrong with this picture? Click image for larger view.
Cromemco System 3 Three Disk Drive Interface Controller 2000uf cap
This photo does a better job to display the problem, the 2000uf 50v cap has blown">... [ read more ]

PDP-11 Still Going Strong

by billdeg
Total messages in this thread: 1
DEC PROFESSIONAL Letter to Editor PDP-11 Still Going Strong
From the Letters section of an un-dated clipping, DEC PROFESSIONAL magazine Spring House, PA. Click image to download PDF
This short letter offers an interesting perspective of the DEC Professional in the late 1980's. Being that many DEC machines are still functional today it would be very believable that a person would choose to continue to use their UNIBUS system, especially an 11/44 into the 1990's. If I was to guess I'd say this letter was published in early 1987.">... [ read more ]

1970 NRI Digital Computer Model 832

by billdeg
Total messages in this thread: 1
Radio Electronics December 1970 National Radio Institute ( NRI ) Digital Computer Model 832 advertisement
Radio Electronics December 1970 National Radio Institute's ( NRI ) full-page advertisement for their Model 832 digital computer trainer. The ad appeared in electronics magazines through 1972. Click image for larger view.
1971 NRI Digital Computer Model 832
The 1970 NRI Digital Computer Model 832 was a trainer kit that was developed in 1970 and sold for $504 US when first introduced. It pre-dates the similar Kenbak computer by many months. Click image for larger view.
... [ read more ]

Vintage Computer Festival East 2019

by billdeg
Total messages in this thread: 1
This humble author's biased pick for best in show, the LNW80 / Lobo Max80 exhibit with spokesmodel, Karen. Click image for more exhibit photos.
Fun event highlighted by Saturday keynote presenters Unix co-inventor Ken Thompson interviewed on stage by Brian Kernighan and Sunday keynote by Atari/Amiga engineer Joe Decuir. ">... [ read more ]

LNW80 Microcomputer Restoration

by billdeg
Total messages in this thread: 1
LNW 80 Microcomputer
The LNW80 computer is a Radio Shack TRS 80 Model 1 clone, more or less. The BASIC is different and the memory map is different. Any programs that rely on either of these things will not operate properly, but DOS PLUS and NEW DOS for the Model I is easily adapted for the LNW80. The photo above displays the opening panel of the Modular Software Associates LNW BASIC Demo. LNW BASIC has commands that employ the LNW80's color display capabilities. Click image for larger view.
LNW 80
With the chassis cover removed, this image reveals a twin control board configuration. On top is the System Ex">... [ read more ]

CDC 6600 Cordwood Logic Modules

by billdeg
Total messages in this thread: 1
CDC 6600 cordwood logic moudle
Pictured are Control Data Corporation 6600 modules. The sandwich-shaped device on the left is called a "cordwood logic module". Each of these contain 64 silicon transistors. The board to the right has the same bus/pin configuration and is likely also from a 6600 or an early "Cyber series" computer, a system based on the 6600. Click image for larger view.
The The Control Data 6600 was considered by many to be the first super computer. More photos">... [ read more ]

~1960 Burroughs Logic Module 72477T

by billdeg
Total messages in this thread: 1
~1960 Burroughs Logic Module 72477T Click image for larger view.
Rear view, same. Click image for larger view.
The Computer History Museum has a similar item, their description reads: "Each module holds eight components: 2 resistors and 6 diodes, mounted on a phenolic frame with two separate common contacts + eight individual contacts." Looking through Burroughs computer and peripheral manuals I have for early 1960's hardware, I cannot say for sure which system the 72477T came from because there are no photos or diagrams">... [ read more ]

My Computer Likes Me when I speak BASIC

by billdeg
Total messages in this thread: 1
The front cover of My Computer Likes Me when i speak BASIC by Bob Albrecht publshed by DYMAX circa 1971-1972. This softcover book was intended to teach BASIC programming to students and persons previously unfamiliar with computers. Students would use this book in a classroom environment in front of a Teletype attached to a mini computer running BASIC.
Here is an example of a lesson, titled "the problem" whose purpose was to demonstrate how the same problem can be solved multiple ways. Click image for larger view.
... [ read more ]

GRiD Compass II Model 1219

by billdeg
Total messages in this thread: 1
Another of Hillary's lost laptops? Obviously this laptop pre-dates the former First Lady's stint with the State Department, but I can only wonder who might have used it. This Compass II 1219 powered up with custom BIOS ROM. Click image for larger view.
Along with this 1219 I picked up a GRiDCASE More GRiD photos">... [ read more ]

DEC PC05 High-speed Tape Reader

by billdeg
Total messages in this thread: 1
Front view of the DEC PC05 high-speed papertape reader. Click image for larger view.
Rear view of same DEC PC05 high-speed papertape reader, where one can see the reader was paired with a PDP 11 system (inset closeup). Click image for larger view.
NEXT - Find the pr11 controller (M7810). Because this is a reader only, it may be possible to use a serial card instead, like a M7800, or with minor modifications.">... [ read more ]

Digital PDP-8 DECUS Music Papertapes

by billdeg
Total messages in this thread: 1
Digital Equipment Corporation PDP-8 Music Program Papertapes 152 152a 162
decus papertapes from 1969 would likely have been written for the a PDP-8i. This is not the same as the RF music program demoed elsewhere on this web site. Click on image for larger view.
TAPE LABELS: 8-152a 8 Music Coding Program Symbolic #1 8-152 8 Music Coding Program Symbolic #2 8-152 Teddy Bear's Picnic Symbolic 8-152a Penny Lane Symbolic 8-152 Joy to the World Symbolic 8-152 Your Mother Should Know Symbolic 8-152a Penny Lane 0037-7720, 0170=7777 0171=7777, 0172=7750, 0173=6020 Binary 8-152 When I'm 64 0037=720, 0170=7776 0172-7750 8-16">... [ read more ]

MAI Jolt 6502 SBC 1975

by billdeg
Total messages in this thread: 2
Updated: [ Origin of the name JOLT ] 12/21/2018
MAI Jolt 6502 microcomputer SBC
The first production 6502-based single board microcomputer - The Jolt pre-dates the MOS KIM and Apple I.
More photos Byte December 1975 ad I had mentioned this system in a "past issue" of when I used to make hard-coded pages for this site. ">... [ read more ]

splicing papertape

by billdeg
Total messages in this thread: 1
Teletype ASR 33 Papertape reader. You can feed a piece of papertape into the reader in local mode to print a section of tape.
I have found that the trick to splicing, aside from having correction patches is sometimes to overlap two pieces of tape, not try to get an exact cut in the program. To do this I stick in an S0 line (filler line) on both sides of the splice. If there is a small tear in a tape that causes the reader to snag, use correction patches. If the rip is too large to patch, you'll have to splice it, just as one would a piece of film. Here are some tips how to do this... Below is a splice of tape, represented by its data. Each 8-bit character is represented by the holes in the tape one at a time as it's fed into">... [ read more ]
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