test-drb January 2008

test-drb@ccmp.vtda.org

221 participants
430 discussions

by jpero＠sympatico.ca

I was working on a monitor, this is romless version but I can take other type as long as I can jumper it to disable the internal programming. I'm fixing a monitor with a flaky 80251. Seems to have many pins output low clocked pulses/noies laid on the signals. The main filters are good, the linear regulators are clean and quiet. Got this microcontroller to spare? Cheers, Wizard

16 years, 11 months

ps2 to ascii keyboard converter

by elazzerini＠interfree.it

Hi at all, i'm working to make alive my bigboard 1. It has input for a parallel keyboard so I'd like to build or to know where to find an interface to convert a ps2 keyboard in parallel way. Well here <http://www.rasmicro.com/FTP/an434.pdf> http://www.rasmicro.com/FTP/an434.pdf there is a schematic to convert ps2 to IIC way. What I asking for is: 1) Is there anyone who know the way to modify the assembly to make the 8xc751 working on its p1.0 to p1.7 output to generate a parallel ascii code corresponding to the key pressed on the ps2 keyboard? 2) What could be the programmer to save the program onto the 8xc751? Thanks Enrico

16 years, 11 months

YouTube videos of vintage PDP-11/40, ASR-33, VT05, etc

by wacarder＠earthlink.net

Somebody recently was asking about wanting to see videos of some vintage equipment in action. I have uploaded some videos to YouTube. These were taken some time back in 2007 one day when I was playing around with my system. The videos are not anything high quality, but do show the PDP-11/40 front panel with the lights blinking, the RL01, RL02, and RK05 drives as they are running, and an ASR-33 teletype, a VT05 terminal, a VT52 DecScope, an LA36 DecWriter II, and an LA120 DecWriterIII as the terminals run the system status program $SYSTAT. Take a look at some live vintage equipment in actions! The URL at YouTube is under the user "WoffordWitch" at: http://www.youtube.com/profile_videos?user=WoffordWitch&p=r If there's anything in particular anyone would like me to video and upload, just reply here or email me at wacarder at usit.net, and I'll fire up the old system and try to accomodate you. Thanks, Ashley Carder http://www.woffordwitch.com

16 years, 11 months

some free DEC boxes in boston area - pickup only

by josecvalle＠gmail.com

Zane.. Hello, from Computer Museum Brazil. I am curator of Museu do Computador , my name Jose Carlos Valle, I will apreciatte to pick up. Please could you send photo of that material? I would like to get it to my Museum here in Brazil. But, I have a friend mine in Dallas, TX, Richard, he will get it and will send to me. Thanks Jose Carlos Valle http://computermuseumbrazil.blogspot.com www.museudocomputador.com.br 2008/1/30, Zane H. Healy <healyzh at aracnet.com>: > > At 1:09 PM -0500 1/30/08, Brad Parker wrote: > >- working BA123 cabinet (with wheels!); no disks, no floppy, no boards, > > no front panel. I think I have the sides, no guarantee. But the p/s > > works fine. Great if you need an open qbus chassis. Plus makes a > nice > > coffee table. > > If you've got all the sides and intact wheels, this is well worth > saving. Even if it is for a VAX, nothing says someone can't > "upgrade" it to a PDP-11. I'd classify it more of an end-table > personally, and I actually used one that way for a few years. > > With a little effort you can also keep a VT420 and LA75 on top of it > and use both. > > Zane > > > -- > | Zane H. Healy | UNIX Systems Administrator | > | healyzh at aracnet.com (primary) | OpenVMS Enthusiast | > | MONK::HEALYZH (DECnet) | Classic Computer Collector | > +----------------------------------+----------------------------+ > | Empire of the Petal Throne and Traveller Role Playing, | > | PDP-10 Emulation and Zane's Computer Museum. | > | http://www.aracnet.com/~healyzh/ | > -- Jose Carlos Valle Museu do Computador & Futuro da Tecnologia tel:+5511-8609-7410 Brazil

16 years, 11 months

How compatible were "MS-DOS Compatible" machines?

by cclist＠sydex.com

> Date: Wed, 30 Jan 2008 11:07:38 -0600 > From: Jim Leonard > > In the early days, it was possible to call BASIC subroutines. But, I > > don't think that they kept the same addresses for long. > > Wow -- while that's cool, what was a useful application for that? > Borrowing the use of the floating-point routines, perhaps? ROM has a > faster access time than RAM, but would it have been all that much faster > than doing it yourself, or would it have just been merely convenient? Any IBM system with BASIC-in-ROM kept the same addresses for subroutines throughout the life of that feature. That's why you can run PC-DOS BASICA only on those machines having the ROM BASIC. For generic MS-DOS, MS supplied GWBASIC as an option (which I still use on my XP-equipped machine when I need to do some quick figuring). Several very early games required BASIC-in-ROM--the basic 5150 shipped with 48K of DRAM, so memory was at a premium. I don't think any productivity tools made use of the ROM BASIC, however. Do any of the IBM diagnostics use it? Cheers, Chuck

16 years, 11 months

some free DEC boxes in boston area - pickup only

by brad＠heeltoe.com

Hi, I don't need the following DEC equipment anymore. Since I got them for free I figured I'd pass them on if anyone wants them: - working BA123 cabinet (with wheels!); no disks, no floppy, no boards, no front panel. I think I have the sides, no guarantee. But the p/s works fine. Great if you need an open qbus chassis. Plus makes a nice coffee table. - MV4000; has cpu & some disks (2 or 3?) it booted vms once and may still. I may have some s cards also laying around (nothing exciting). Worked fine last time I powered it up. Marginal as a coffee table; perhaps an end table. - MV3100 + associated scsi disk box. Last ran netbsd and worked fine. No idea what is on the disks. I think I have one scsi cable also. Not tall enough to be a coffee table. too heavy to server as paper weight. I can't ship these. If you want them you need to pick them up. I'm in Arlington Mass (USA) 02476. You can pick them up most any time. (I can't get at my 14" disks right now and those need to be spun up :-) -brad

16 years, 11 months

Z80 Divide by 10

by cclist＠sydex.com

On 25 Jan 2008 at 12:00, cctalk-request at classiccmp.org wrote: > I figure that one might do part of the multiplication and then > right shift the result some since were are going to truncate the > LSBs anyway. The first result is expected to error some. With > the correct value for the multiply, the error will always be on > the low side, keeping the error calculation simple. The largest > error seems to grow linearly so even with some truncation, > one should be able to hit 10K or so with only 1 or2 conditionals, > using a large fractional munber to multiply. > I don't think I'd ever use this but it was fun to think about. I suspected that this is what you might be doing (that ADD HL,H really had me wondering), but I wonder if your method will hold together for accuracy or be faster than a simple unrolled 10 bit divide. Remember that without the need for an iteration test you can use BC to hold the scaled +10 and use a DAD instead of an SBC, shaving a byte from the loop. Cheers, Chuck

16 years, 11 months

DEC Highnote P8x

by steve51158＠hotmail.com

Hi sorry to bother you,I came across a CCtalk archive from Nov 2003 regarding power supply pin out connections for a DEC Highnote notebook.I have recently aquired one of these but have the same problem,no power supply,I have an old non working DELL adapter which looks to have the same connector so if you still have the info on the connections that would be a big help,thank you. _________________________________________________________________ Share what Santa brought you https://www.mycooluncool.com

16 years, 11 months

.. 1973... Intertechnique Multi 8 / Microdata 800-1600

by pichotjm＠free.fr

Hi, Thanks for information. I have added your comment on my http://pichotjm.free.fr/Multi8/Multi8.html page. Do you accept that? I have found 2 more photos showing me working with another Multi 8 configuration, but i have to restore them (many scratches, white dots...)! May be from 1972. I was debugging one of these applications: http://pichotjm.free.fr/Techno73/Applis/Applis.html Electronic contains the first microprocessor 4004. Unfortunatly, i have no document about this. JMP

16 years, 11 months

Help needed on a DEC LA180 printer

by RodSmallwood＠mail.ediconsulting.co.uk

On switch on the printer will seek the margin. If there's a problem with the position encoder or photocell the motor will not stop. With the printer off make sure the head carriage is free to move and the bar it slides on is not bent. You can put a little oil on the head slider bar. As with above if the head jams before it gets to the rest position. The stall current from the motor will trip the alarm. Rod Smallwood DEC Terminals Product Line 1975 - 1978 -----Original Message----- From: cctech-bounces at classiccmp.org [mailto:cctech-bounces at classiccmp.org] On Behalf Of Harten Sent: 29 January 2008 20:25 To: cctech at classiccmp.org Subject: Help needed on a DEC LA180 printer Hi! I'm a Computer collector from Germany and the last 3 years i spend a lot of time in reconstructing and repairing my PDP11/05 along with its peripheral devices (2x RK05,RX02,BA11ES). Noe that these things are working im trying to repair my LA180-PD printer, that was in no good condition. With a copy of the logic-prints i was able to find some faulty IC's on th logic board- but there must be at least one more. On Power-Up the carriage starts to move back to left edge but stopps before reaching the left end then the bell is turned on permanently. There is no reaction on any button pressed or switched over. Unfortunately i have no Maintenance Manual or Logic description, maybe there is a person out on this list who can help me with a copy of the documents. Regards Axel Harten.

16 years, 11 months

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test-drb January 2008