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E.L. Instruments Trainers

by billdeg
Total messages in this thread: 1
E.L. Instruments Elite 2 Circuit Design Test System
The E.L. Instruments Elite 2 Circuit Design Test System. Click image for larger view.
E.L. Instruments Digi Designer DD-1
E.L. Instruments Digi Designer DD-1. Click image for larger view.
More photos A not-quite-a-computer trainer that you often see pop up in auction sites, must have been popular once in schools, etc.">... [ read more ]

Dell Dimension XPS 466V

by billdeg
Total messages in this thread: 9
Updated: [ Replace Dead Motherboard ] 04/09/2017
Dell Dimension XPS 466V
The 1993 Dell Dimension XPS 466V was one of the nicer 486 gaming machines built before the Pentium era. Click for larger view.
This computer needs a real time clock battery (CMOS). Currently one has to run Setup for each cold boot. This system has two Caviar model 2340 341 Mb hard drives. I installed a 1.2Mb 5 1/4" disk drive for utility purposes and I may add a CD ROM in the remaining open slot below the 1.44Mb 3.5 inch disk dive in the middle bay. Dell Dimension 66 mHZ 486 CPU... [ read more ]

Vintage Computer Festival East 12

by billdeg
Total messages in this thread: 1
Bill Degnan Appliance Computers Talk at the Vintage Computer Festival East 12, 2017
I was the Sunday Keynote speaker, my talk was titled, 1977: The year of the appliance computer
Event Photos 1977: The year of the appliance computer (Download PDF) The photos I took do not do justice to the actual exhibits and how they looked in person. First off they were all an amazing amount of work, classy, and great teams. All three mega exhibits were "best" in show as far I am concerned. We were talking about what we'll do next year with teams, never too early to start planning. I'd like to propose we try a vintage networking cluster, "pass the packet" or somethi">... [ read more ]

VCFed Workshop Feb 2017

by billdeg
Total messages in this thread: 1
Commodore PET 2001-8
I spent most of my time working on a sick PET 2001-8. The display board failed. Click for larger view.
Commodore PET 2001-8
Pic of the friend resistor. I replaced this component, but we did not have a TIP29 that I think was the reason the resistor fried. This resistor has been replaced before. Click for larger view.
Mac 400K drive repair... [ read more ]

KE11-E M7238 EIS Diagnostics

by billdeg
Total messages in this thread: 1
industrial/11 with frozen front panel after attempting to load UNIX without a working EIS controller card. The KE11-E Extended Instruction Set (EIS) is required for UNIX 6.
Up to this point I had not messed with using the optional EIS card, M7238, KE11-E in my 11/40 system testing. UNIX 6 requires this card, so I am going to test the card. Not sure if it works. Here is the basic info for the controller: KE11-E M7238 Extended Instruction Set EK-KE11E-OP-001 EK-KE11 E-OP KE11-E/F USER MANUAL EK-KE11E-TM KE11-E/F TECHNICAL MANUAL MP-KE11-B KE11-E MAINTENANCE PRINTS The manual says to cut the W1 jumper on the M7233 Decode card, which I did, as part of installation, plus attach the three ribbon cables between the M7238 and M7232. When I run the system wit">... [ read more ]

Booting the System Using RL02 drive

by billdeg
Total messages in this thread: 14
Updated: [ Progress / Checking Disks ] 02/01/2017
M9312 Bootstrap Terminator CONSOLE Test
I set the jumpers on the M9312 card to use the CONSOLE program. The CONSOLE is a monitor program that allows a person to load a RAM address, change memory, load and run programs rather than have to rely on the front panel. This image shows the echo character program from the manual. The last line reads: @STHIS IS A TEST.... @ is the prompt, S is the start command. I then typed THIS IS A TEST, without a LF CR. Click on image for larger view.
I have one RL01/RL02 ROMS that I can use with the M9213. I read the ROM to compare with the bootstrap listed below to verify I have the correct ones. The RL02 bootstrap is here https://ak6dn.dynd...9/23-751A9.lst Below I">... [ read more ]

Slugging it through XXDP Diagnostics

by billdeg
Total messages in this thread: 14
Updated: [ XXDP+ ] 02/01/2017
DEC PDP 11/40 and RL02 undergoing repairs
PDP 11/40 in chassis with rack arms extended. RL02 sitting on top of rack. Click image for larger view.
Found at lot here, but not ZRLG or ZRLH http://www.retro...evices/RL02.html so, I am going to try the maindec-11-dzrla-a-pb1 and maindec-11-dzrla-a-pb2 - and I see that ak-e038b-mc and ak-e039b-mc I think replaced the first two. * * * * * * UPDATE - found page 2-40 RL01-RL02 user guide to confirm CZRLAAO and CZRLBAO are correct. "..These diagnostics can be run free-standing under the Diagnostic S">... [ read more ]

Commodore Announces 128K Computer

by billdeg
Total messages in this thread: 1
Commodore B(C)128 Product Announcement, Byte Feb 1985
Notice anything wrong with this February 1985 product announcement, in Byte Magazine? Here is your hint. Click image for entire announcement.
The question is, was this a print error or did they really mean to call their new computer the B128? Were the various product departments within Commodore really that disconnected to not know of the real B128, forcing a last-minute name change, to C128? I know the original B128 was developed at about the same time as the C64, and flopped pretty quickly. Protecto bought out the inventory from Commodore and was still actively selling B128's in 1985 and for a number of yea">... [ read more ]

Diagnosing PDP 11 h742a 15V failure

by billdeg
Total messages in this thread: 1
The backplane lost the +/- 15V signal while I was testing the drive controller.
The power supply is hard to get to in the rack. Pictured is the h742a power supply disconnected from the rack but not the computer. I positioned two cinder blocks on each side of the rack with a strong board between them to form a table. Unbolted from the rack I was able to move the h742a 90 degrees to sit it on the board with the power connections intact. Now the unit is much easier to access. Click image for larger view.
I removed the power control board from two h742s including the">... [ read more ]

simH notes

by billdeg
Total messages in this thread: 3
Updated: [ CHIP connection to serial terminal ] 01/14/2017
pocket CHIP simH RT-11
simH RT-11 running on the Pocket CHIP single board computer.
Here is the simh layout I have settled on so I can have all types of emulation in one place. I have a /BIN for the emulator bin files (altair, pdp11, nova, vax, etc.) created by the MAKE process from the source files. I also created a directory for each emulator to hold system-specific ini and media files. Assuming you're using a linux for these things, and you're set up the same way... 1. Log in 2. $ cd [../simhdir]/[emulatordir] where [emulatordir] = name of system such as pdp11 eg. $ cd/simh/PDP11 3. $ ../BIN/pdp11 (the file that the MAKE process created you want to use) 4. At this point you should be at the simh> prompt. sim">... [ read more ]

Looking for Help with Tandon 602S

by falen5
Total messages in this thread: 2
Updated: [ Tandon 602s 603s SASI ] 01/08/2017
I am a vintage computer collector and recently acquired a strange machine that seems to be hacked together from a machine from Yugoslavia , an apple ii, what i think is tandon 602S 5mb hard drive, with the controller board and an interface to the apple II.A Diy powersupply, 12' onboard monitor and analog board, 5.25' floppy drive. I have made a video log of my findings with this machine. At present I am trying to get the motherboard working. When it is working I will be rebuilding the machine. The tandon drive is the big question as I have no idea about these drives or how to acess it. Here is a link to the first part of this 9 part video log.. so far. https://www.yout...DXmQU&t=1308s Please excuse my 'colorful' irish language. cheers Adrian ">... [ read more ]

PDP 11/40 Industrial 11 model

by billdeg
Total messages in this thread: 3
Updated: [ Front Panel Repairs ] 12/22/2016
PDP 11/40 expansion chassis
Digital made a PDP 11/40 "industrial11" model. The front panel coloring is different but otherwise operates the same as the standard unit.
PDP 11/40 industrial 11 bottom chassis card cage
Pictured here is a view of the bottom card cage with the main CPU and memory module. Click image for larger view.
PDP 11/40 industrial 11 expansion chassis... [ read more ]

Commodore BASIC test program

by billdeg
Total messages in this thread: 1
Looking for a nice screen save type graphic for your Commodore 64 and probably many other platforms? 10 PRINT CHR$(205.5+RND (1));:GOTO10">... [ read more ]

Visual Technology Inc Model 1050

by billdeg
Total messages in this thread: 15
Updated: [ XEBEC Drive Controller Overheating? ] 12/16/2016
The Visual Technology Inc Model 1050
I have a perfectly working Visual Technology 1050 system with Winchester hard drive option. There is however one problem. I have three keyboards and they're all bad. The problem is similar to that of the Processor Technologies SOL Terminal Computer and other keyboards made with a foam contact pad in each key. About 25% of the pads have turned to dust. To format the Winchester drive I was forced to swap keyboards just to get certain keys to print on the screen. I needed all three keyboards to initiate the hard drive format! There has to be an easier way.
The Visual Technology Inc Model 1050 keyboard.
">... [ read more ]

Atari 1200XL (1983)

by billdeg
Total messages in this thread: 1
Atari 1200XL Pitfall!
The 1983 Atari 1200XL computer, with Pitfall! cart in use. Click image for larger view.
Here is a closeup of the Pitfall! screen. It looks more or less the same as the Atari 400 and 800 systems' display of the same cart. In fact my testing shows that one could use any 400/800 cart in the 1200XL. Click image for larger view.
Close up view of the Atari 1200XL. Click image for larger view.
I got this compute">... [ read more ]
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