test-drb February 2013

test-drb@ccmp.vtda.org

185 participants
407 discussions

let's try this again... how do you build a floppy disk?

by rampaginggreenhulk＠yahoo.com

------------------------------ On Sat, Feb 16, 2013 8:44 PM PST Chuck Guzis wrote: >On 02/16/2013 07:51 PM, Chris Tofu wrote: >> >> start with a disk... >> >> Then what? smear on some rust? is it sprayed on? once you get the >> chemistry correct it doesn't sound like the application portion >> should be that challenging. is there an adhesive applied first? >> Afterwards? Where's that Jeri lady. Get her on this LOL > >Well, no, you don't start with a disk. That would be silly. > >You start with a very wide blanket-on-a-roll of substrate. You mix the binder and oxide together in a thick paste and spread them on the sheet. I suspect that the thickness of the coating is regulated by a "doctor blade" setup. The coating is cured and then round disks are punched--the result is called a "cookie" for obvious reasons. It's then verified and inserted into the jacketing medium, sealed and packaged. Not so fast bucko. Got to flip the blankee over and coat that side. >The oxide coating on a 5.25" DD floppy is not much different from that of VHS videotape. I suspect that the demise of floppy manufacturing to more a case of video- and audiotape dying off. I would think what put the kybosh on both were advances in optical media, which became a solution for computer storage earlier then video. Both useful.posts though. Anyone think this can't be done? Is choice of substrate that critical? Question in my mind is how to control the thickness. This is why I had thought spraying would be appropriate. Maybe it is.

12 years, 12 months

DG Nova repair etc.

by RolexTM＠gmx.de

> The original Nova has a 4 bit ALU What do you mean? I think i did not get your answer. >> When I got my Nicolet, I had a similar sounding problem.It turned out to be a missing clock.Of course, yours may be soemthing different but you aregoing to need some schematics and a scope to track down.( I did mine without a schematic but I was lucky ).Dwight We already sighted most of the pdfs and schematics at bitsavers and simh. We have a scope and logic analyzer and some experience in component level repairs of electronics. This machine is just a bit harder to diagnose than for say our old VT100...the documentation is overwhelming and my brain has not adapted to it well atm ;) so i just hope to get somebody that has intimate knowledge of the machine.... The problem of the machine only running on single step and not on "run" may well be related to a missing clock, although i wonder if even single instruction stepping would work without clock since it also needs some form of clock to single step through one asm instruction...although i might be on the wrong train since there may well be more than one clock inside the machine.

12 years, 12 months

Introduction and IBM 1130 replica project

by Carl.Claunch＠gartner.com

Dave wrote: > > Has anyone done an FPGA emulation of the 1620? > > I don't think so. Of course there already is an FPGA emulation of the > 1130 by Richard T. Stofer which does plotting to an HPGL plotter. There is a video of his presentation to the 06 1130.org party here:- > > http://ibm1130.org/party/v06 > > I also have hacks to the SIMH emulation to drive an HPGL plotter. > Video of it in action here:- > > http://www.youtube.com/watch?v=SCUUgLvVvpg > Richards excellent work was what first got me involved with this - after watching his talk and contacting him, he shared his code and expertise to allow me to create a copy of his emulator. It inspired me to learn hardware design and electronics and to aim for my project. Richard designed his machine by designing hardware that would match the Functional Characteristics manual, analogous to how Amdahl designed an IBM compatible system by adhering to the Principles of Operations but adopting their own unique design within the machine. He did not have a goal to emulate the hardware console functions such as Single Step, Single Memory Cycle, Interrupt Run, Load, and so forth. Since I first got hands on experience with computers on an 1130, learning by using those controls and watching what my code was causing to happen, I wanted to recreate to that level. My machine is built to map almost exactly onto the logic gates of the 1130, as I used the ALDs (automated logic diagrams) to recreate the system. It is designed to run at the same speed as the physical 1130. It is therefore a cycle by cycle faithful recreation, allowing someone to see what changes when releasing the Start key in Single Step mode at cycle T4 of instruction phase E1, which is phase B of the clock. Certain conditions change or actions take place on specific phases of those cycles - this recreates them. I also mapped all the hardware adapter logic faithfully and built hardware to emulate all the signals that came into the 1130 from the peripherals. As a final step, I adapt real hardware I have, an Electronic Typewriter 50 (selectric ball type machine), to link to my hardware emulation so that it behaves the same. My keyboard is a photocell driven partially mechanical unit from a keypunch of the era, interfaced to link to the 1130 adapter circuits and present the exact signals that would come from the real 1130 keyboard hardware. I built the display light pedestal above the console printer to scale, as another example of my obsessiveness. My aim is to replicate the experience of running an 1130 hands on. This certainly is no denigration of the emulator built by Richard Stofer - it provides higher performance than a real 1130 and from a programmers standpoint is a truly faithful replica. For most people, that is all the recreation they want. Beyond that, there are software simulators such as the one hosted by Brian Knittel at http://www.ibm1130.org with a full set of 1130 software at the same site - highly recommended. This project has allowed me to meet a number of great people who have offered advice, aid and a supportive ear as I toiled away - I try to credit them all in my blog, but it is possible I haven't mentioned all of them. I am also indebted to Al Kossow and the Bitsavers archive for availability of ALDs and other documentation sufficient to produce this hardware level recreation. > But for the 1620 nothing so far. There is Java based emulator but the only software thats been converted is the diagnostics. Al did load up the other stuff he has to bit savers , but I havn't had time to look at it, as I got distracted by a project to connect some Creed equipment from a Ferranti Pegasus to a software emulator.... > Sounds like you are having some fun yourself. Hope it is going well. >> That one has a soft spot in my heart to the extent that I can still >> remember the numeric opcodes for many instructions. The 1401 occupies >> a similar place in my memories. Little IBM boxes were really cute. >> > >The 1620 I used wasn't what I would call "cute" but it was the second machine I programmed. I guess we are all bonded by an appreciation of early technology machines that were formative for us. Carl ________________________________ This e-mail message, including any attachments, is for the sole use of the person to whom it has been sent, and may contain information that is confidential or legally protected. If you are not the intended recipient or have received this message in error, you are not authorized to copy, distribute, or otherwise use this message or its attachments. Please notify the sender immediately by return e-mail and permanently delete this message and any attachments. Gartner makes no warranty that this e-mail is error or virus free.

12 years, 12 months

Question about NeXT 17" B/W monitor

by IanK＠vulcan.com

Does anyone know the part number for the CRT in a 17" NeXT monochrome monitor? I've cast about for a schematic that shows it to no avail. I've opened up the monitor (N4000A), and the number is not evident. The internal frame bears a Sony name and number, SMC-311A. I fear the number may be hidden under the yoke - which I'd rather not pull free, for obvious reasons. Before I start getting dramatic with this thing, does anyone know the part number? I'm going to try rejuvenating the CRT, per a comment by Ethan a little while back (I acquired a B&K for $9 on ePay). Nearly all of the 17" CRTs have the same switch settings, but count on Jobs to have picked an off one. :-) So it seems wise to tap the collective wisdom before just crossing my fingers. Thanks -- Ian

12 years, 12 months

let's try this again... how do you build a floppy disk?

by rampaginggreenhulk＠yahoo.com

------------------------------ On Sat, Feb 16, 2013 8:36 PM PST Nigel Williams wrote: >On Sun, Feb 17, 2013 at 2:51 PM, Chris Tofu ><rampaginggreenhulk at yahoo.com> wrote: >> Then what? smear on some rust? is it sprayed on? once you get the chemistry correct it doesn't sound like the application portion should be that challenging. is there an adhesive applied first? > >There is a short section here about the raw materials and process: > >http://www.madehow.com/Volume-1/Floppy-Disk.html > >It would seem that the community might want to track down this document (book?): > >Aronson, Susan. Diskette Reference Manual. 3M Data Storage Products >Division, 1990. > >I notice that this fellow references this document too: > >http://www.retrotechnology.com/herbs_stuff/drive.html Smashing research excellent research

12 years, 12 months

let's try this again... how do you build a floppy disk?

by rampaginggreenhulk＠yahoo.com

start with a disk... Then what? smear on some rust? is it sprayed on? once you get the chemistry correct it doesn't sound like the application portion should be that challenging. is there an adhesive applied first? Afterwards? Where's that Jeri lady. Get her on this LOL

13 years

Northstar Dimension keyboard question

by rampaginggreenhulk＠yahoo.com

------------------------------ On Sat, Feb 16, 2013 7:17 PM PST Fred Cisin wrote: >> > I won it. It resembles a Keytronic 5150, but has something like an rj11 >> > (don't ask me how many conductors). Is it an IBM/K* internally? >> >No. > >On Sat, 16 Feb 2013, Chris Tofu wrote: >> How do you know? > >Because in 1983, Michael Swaine (Infoworld) called the Dimension, "PC >compatible". I fail to see what that has to do with the keyboard >How many "workstation" terminals did you get with it? exactly 0. is that a bad thing? the monitors that I see pictured with it look just like an Eagles. which could mean they are 5151 compatible. which could mean it might have more aspects of compatibility then you might think. in any event it's a toy to play with and now I have a keyboard. I have discs but something tells me they're not going to be what I want them to be. I know it doesn't run MS DOS natively but it might be fun to try. it's not intended to be a product tivity tool.

13 years

Cyclone CVME961

by BHuntsman＠mail2.cu-portland.edu

Here's an odd one... Anyone here ever seen, heard of, or have a Cyclone CVME961 board? Thanks in advance! -Ben

13 years

Northstar Dimension keyboard question

by rampaginggreenhulk＠yahoo.com

------------------------------ On Sat, Feb 16, 2013 5:44 PM PST Fred Cisin wrote: >On Sat, 16 Feb 2013, Chris Tofu wrote: >> I won it. It resembles a Keytronic 5150, but has something like an rj11 >> (don't ask me how many conductors). Is it an IBM/K* internally? >No. How do you know? >> I guess >> I should have asked before I bid/bin.

13 years

any interest in an IBM Displaywriter

by rampaginggreenhulk＠yahoo.com

Yeah. Gone. ------------------------------ On Sat, Feb 16, 2013 6:30 PM PST Nigel Williams wrote: >On Thu, Jul 5, 2012 at 2:11 PM, Chris Tofu <rampaginggreenhulk at yahoo.com> wrote: >> I payed 100$, and had to pick it up in Queens/Nassau. I'll take 50$ plus shipping, from 08758. It works, but >> there is noticeable screen burn even when off. I have some disks, and >> the 8" drive cabinet. > >did someone end up taking this off you?

13 years

← Newer
1
...
21
22
23
24
25
26
27
...
41
Older →

Jump to page:

2026

2025

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 February 2013