test-drb March 2015

test-drb@ccmp.vtda.org

167 participants
224 discussions

Tek 1200 series GPIB interface available

by jnc＠mercury.lcs.mit.edu

Hi, I acquited (with a Tek 1240 I recently got) a 1200C02 GPIB Comm Pack, which I have no use for. Dunno if it works or not. Looking for a good home for it - shipping plus whatever donation the receiver feels is appropriate. Noel

9 years, 1 month

Looking for PSS RAM65 S100 Manual

by philip＠neoncluster.com

Hi all, I have a Problem Solver Systems (PSS) RAM65 card that I would like to get working in my IMSAI 8080, but I can not find any manuals for it online. Does anyone on the list have a manual they could possibly scan for me. Much thanks in advance. Philip

9 years, 1 month

DEC PDP-11: 330 XXDP listings scanned from micro fiches

by shadoooo＠gmail.com

Wonderful!!! :) Andrea

9 years, 1 month

DEC PDP-11: 330 XXDP listings scanned from micro fiches

by jnc＠mercury.lcs.mit.edu

> From: J?rg Hoppe > Over the last months I scanned micro fiches with XXDP diagnostic > program listings ... I digitized 330 listings from 452 fiches, with a > total of 53545 document pages. Wow! That is a fantastic job, and I'm sure they will be incredibly useful to the community. Thank you! Thank you! Thank you! Noel

9 years, 1 month

DEC PDP-11: 330 XXDP listings scanned from micro fiches

by lbickley＠bickleywest.com

Joerg, On Sat, 21 Mar 2015 07:46:09 +0100 J?rg Hoppe <j_hoppe at t-online.de> wrote: > Hi all, > > Over the last months I scanned micro fiches with XXDP diagnostic > program listings. > These listings are essential for repairing PDP-11's (or enhancing > SimH). I digitized 330 listings from 452 fiches, with a total of > 53545 document pages. > Almost all of them should be new stuff. --snip-- Great job. A serious "labor of love". Thanks a LOT! Cheers, Lyle -- Bickley Consulting West Inc. http://bickleywest.com "Black holes are where God is dividing by zero"

9 years, 1 month

Kaypro 4 + 88 boot disk (81-232 ROM)

by brain＠jbrain.com

There seems to be quite a few options for a boot disk for a K4+88 here: http://www.retroarchive.org/maslin/disks/kpro/ The unit has a 81-232 ROM. Gene (again, thanks), sent some disks, but the 81-232 one did not work. I created a disk from one of the images on the site, and the unit boots (yay!), but not sure if I am using the best image for the unit. Any particular image I should use? Also, any links to the '88 stuff for this unit? Jim -- Jim Brain brain at jbrain.com www.jbrain.com

9 years, 1 month

How to save two Mitsubishi M2896 drive (spindle motor smoked!)

by enrico.lazzerini＠email.it

Well, i desolder the LB1620... it has obvious signs of burning under the chips and also on the pcb. I saw the smoke coming from that place but I thought it came from one of cap of 2700pf instead came from the chip. The short circuit between +24vdc and the ground is gone out.   +24vdc go just at pin 4 of the LB1620. +24vdc to R112 and the D102 Zener that is saved so from here to pins: 19, 2 and 12 of the LB1620 then it continue to pin 16 of the TC9142P. The datasheet of this last one say that the power voltage would be between 5Vdc and 9,5Vdc. So would this say that the zenere has to be from 5 to 9 vdc? Have i to measure the exact voltage on pin 16 of the TC9142P without the  LB1620 and how have i to expect?   The LB1620 is smoked. What other components must be tested to ensure that the new LB1620 can not be broken just fitted?   Thanks a lot.   E.     --------- Original Message -------- Da: "General Discussion: On-Topic Posts" <cctech at classiccmp.org> To: "General Discussion: On-Topic Posts" <cctech at classiccmp.org> Oggetto: Re: How to save two Mitsubishi M2896 drive (spindle motor smoked!) Data: 02/03/15 04:20 Indeed, pin 4 (Vcc1) should be +24V, this is for the motor windings drive. You need to look at pin 19 (Vcc2) of the LB1620 or the voltage across zener D102. Follow the pcb trace from the junction of R112 and D102, goes to pin 19, looks like pins 9 & 2 as well, and on to supply the other ICs. On 2015-Mar-01, at 1:38 PM, Enrico Lazzerini wrote: > > Mhmhm... i checked the pcb. The LB1620 pin 4 is wired to the pin on which I > think comes +24vdc... so... let me check what could happens before. Could > happens that is it broken something and it goes to this little pcb +24vdc > instead of 12-15vdc??? > > I misured the voltage coming to this pcb and over there is +24VDC > This explain well the why this pcb smoke and it is hot. > > > Enrico > > -----Messaggio originale----- > Da: cctech [mailto:cctech-bounces at classiccmp.org] Per conto di Brent Hilpert > Inviato: domenica 1 marzo 2015 22:08 > A: General Discussion: On-Topic Posts > Oggetto: Re: How to save two Mitsubishi M2896 drive (spindle motor smoked!) > > > On 2015-Mar-01, at 9:56 AM, Enrico Lazzerini wrote: > >> Thanks Tony for your suggestions. What I means is: >> >> It happen in two distinct times every time when I used the drive to read >> through a PC with the software IMD to create images of floppy disks 8 ". > Not >> having the correct power connectors i power the drives in this way: + 5vdc >> and ground coming by a PC power supply and +24vdc and ground from a > Chinese >> power supply. I must have certainly reversed this last one even for a few >> seconds exchange +24vdc with the ground. Now both spindle motor supplied >> also with only +24vdc start smoking in the vicinity of the chip LB1620 and >> cause of cooling you can not touch it as hot it is. If I try to measure > the >> resistance between pins +24vdc and ground of each spindle motor drive i > get >> 1327ohm on FD0 while i measure 19ohm on the spindle motor drive FD1. There >> are no visible damage nor to the components nor the PCB wires. >> In both pcbs anyway the chips LB1620 sunburnt from not being able to keep > a >> finger on it. >> I searched on ebay and the only place that has LB1620 seems to be: >> > http://www.ebay.it/itm/LB1620-INTEGRATED-CIRCUIT-IC-BOX-74-/390955452872?pt= >> LH_DefaultDomain_0&hash=item5b06c2c9c8 >> >> The input's pins of the pcb are : +24vdc, ground, and the rest could be a >> control. >> >> The point is that I have no experience on these components. >> Replace the chip could make it burn again for my inexperience. >> > > I notice in one of the photos you have written 15V for the zener D102, and > on both boards they look like they have been replaced. > > D102 and R112 are a simple regulator to reduce the +24V down for the chip > supplies (looking at the photos to trace the circuit). > +24 is otherwise used directly only for the motor windings, in part via Vcc1 > on the LB1620. > > The LB1620 datasheet specifies the Vcc2 range for the 1620 to be only 8.5 to > 14V, not 15V. > > Check the Vcc2/zener level to see whether the zeners are good and what > voltage they are. > I expect Vcc2 (and the zener V) is supposed to be 12V or 9V. > -- ZE-Light e ZE-Pro: servizi zimbra per caselle con dominio email.it, per tutti i dettagli Clicca qui http://posta.email.it/caselle-di-posta-z-email-it/?utm_campaign=email_Zimbr… Sponsor: Idee regalo classiche o alternative? Trova l'offerta migliore in un click Clicca qui: http://adv.email.it/cgi-bin/foclick.cgi?mid=13327&d=2-3

9 years, 1 month

4 MB memory unibus/qbus card (was Qbus split I&D?)

by jnc＠mercury.lcs.mit.edu

> From: Mark Kahrs > there are very nice SRAMs available: for example, the Cypress CY62167 > is a 2Mx8 1Mx16 RAM in 48 pin TSOP. So you'd need two ... > (n.b. there is a 4Mx8 but it's only in BGA, so fuggitaboutit). Actually, one 4Mx8 (assuming it's really only 8 bits wide) wouldn't be as easy to work with as two 2Mx8; since most QBUS cycles are 16-bit word, not byte, you'd have to do two memory cycles for each QBUS cycle -> more complexity. Noel

9 years, 1 month

Old NTSC tricks: 240p?

by tsw-cc＠johana.com

A discussion about sync rates on a TV signal. Christian Corti <cc at informatik.uni-stuttgart.de> Wrote: > This has absolutely *nothing* to do with NTSC or PAL (or SECAM or > whatever). NTSC etc. are colour encoding standards and don't describe in > any way how a image signal is generated (fields, syncs, timing). They only > describe how to put colour information into the signal. > Christian Sorry, but this is UNTRUE.? There have been several NTSC standards. The first one defined the signals for standard Black/White TV, it dates from the 1940s.? It defined such things as horizontal sync, vertical sync, field definitions,? and equalizing pulses (among other things).? This version used a horizontal sync rate of 15750Hz, and a vertical sync of 60Hz (field rate).? The later NTSC standard (from the 1950's) added the color definitions (color burst, re-definition of horizontal sync, color phase signals, color sub-carrier, etc.).? This version reduced the sync rates by 0.1%, yielding a horizontal rate of 15734Hz, and a vertical rate of 59.94Hz.? This was needed to make things proper multiples of the color burst rate.? A later definition added stereo audio (related to horizontal sync). If you know things about the signal, you know that there are 4 field types in NTSC color that differ with phase start of color burst, and odd/even field.? I believe that PAL has 8, but I'm not exactly sure. Yes, PAL and SECAM are color definitions.? They are encoded over various underlying TV sync systems.? One can make a SECAM receiver work a PAL signal. Many of the broadcast standards have been dictated by governments.? I believe that the 625/50 standard is "CCIR"? What devices generate is anybodys guess.? What TV sets accept is a crap shoot if it isn't "standard".

9 years, 1 month

Amiga 30th anniversary event kickstarter in July at CHM

by jfoust＠threedee.com

<https://www.kickstarter.com/projects/890300835/amiga-30th-anniversary-in-ca…>https://www.kickstarter.com/projects/890300835/amiga-30th-anniversary-in-ca… - John

9 years, 1 month

← Newer
1
...
7
8
9
10
11
12
13
...
23
Older →

Jump to page:

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

2001

2000

1999

1998

1997

test-drb March 2015