test-drb October 2005

test-drb@ccmp.vtda.org

264 participants
655 discussions

by news＠computercollector.com

I'll be in town Wedneday to work on my exhibit, that way I don't have to transport the whole thing from New Jersey. Anyone want to hang out Wednesday night for dinner / drinks? (I have plans already for Thursday). Friday, of course, is VCF set-up day at the museum. Staying at the Quality Inn Mountain View, best way to reach me will be cell phone (646.546.9999) or periodic email. Wish I could get my IBM Simon working alongside my Treo. ;) ----------------------------------------- Evan Koblentz's personal homepage: http://www.snarc.net Computer Collector Newsletter: http://news.computercollector.com Mid-Atlantic Retro Computing Hobbyists & Museum: http://groups.yahoo.com/group/midatlanticretro/

18 years, 9 months

Flip Chips was Re: US Sources for old ICs

by tshoppa＠wmata.com

Paul wrote: > "Flip Chip" as a DEC trademark simply designates the PC board with > stuff on them that implements some function and can be plugged into a > backplane. That's what it ended up meaning, and most of the modules indeed were made up of discrete wire-lead components and DIP's on a plug-in card. But DEC's original intention was a much closer bonding of a hybrid module to a PCB sans wires. See my thread in a.f.c. on this topic in 1998 :-). Tim.

18 years, 9 months

Z80 Telescope Controller (was Homebrew newsgroups / forums?)

by dwight＠ca2h0430.amd.com

>From: gtulloch at shaw.ca > >Well, ok, in that case ... > >I'm building a Z80 based microcontroller as a telescope controller, to >run a few stepper motors, calculate and correct for periodic errors as >well as XYZ errors in the mount. The driver circuit is done >(http://www.bbastrodesigns.com/cot/steppercircuit.html), and >currently runs off a DOS app which uses the parallel port to pulse >the motor windings. However, I prefer not to use a dedicated >DOS PC so I'd like to put a Z80 in front of the driver with an RC >circuit connected to the NMI so I know how long the duration between >interrupts is and can thus calc the steps required to track. For historic >reasons the code will be written in FORTH - a PC connected via serial >will do all the heavy lifting as far as telling the Z80 where to point >and how. Comments on the veracity of this architecture welcome! > >I have a few questions I'm hoping someone can answer for me, starting >with the following: I have a Z80A and a 4 mhz TTL clock >oscillator - I'm wondering if it would be ok to connect the clock >directly to the CPU or is it wise to connect it via a parallel or >serial resonant oscillator circuit like those described here: > >http://www.z80.info/uexosc.htm > >Why be so elaborate? The data sheets for the oscillator doesn't say >"Make sure you connect via a parallel or serial resonent oscillator >circuit!" > >Thanks for any light you can shed on this, Google hasn't been helpful. >I have references that do it both ways without explanation so I'm >confused! Hi I think you are confusing a crystal oscillator with a crystal. The circuits shown are for the crystal alone and you provide the oscillator. If you are using a crystal, one needs to match the type of crystal, parallel/series, to get it to work at the stated frequency. This has to do with the phase shift that the crystal provides for the oscillator. In one case, the phase is 0 degrees while the other, it is 180 degrees. Even so, using ttl parts for oscillators can have issues. If the crystal is over driven, it will age quickly and drift in frequence or even fail to oscillate. Also issues like startup time need to be addressed in some applications. You'd want the oscillator running well before releasing reset on a CPU. Dwight > >Regards, > Gord > >cctalk-bounces at classiccmp.org wrote on 26/10/2005 09:25:58 PM: > >> Gord wrote... >> > I'm building a Z80 based computer as a stepper motor controller, and >it >> > would be nice if there was a homebrew newsgroup to ask questions on >since >> > I don't think this is the group to do so - any recommendations? >> >> Um... I would certainly think developing a new system around a classic >> processor (Z-80) is certainly ok on this group :) >> >> Jay >> >

18 years, 9 months

FPGA VAX update

by msokolov＠ivan.Harhan.ORG

Scott Stevens <chenmel at earthlink.net> wrote: > How well do they encrypt the ZIPs? There are some pretty powerful > ZIPcracking tools out there. Well, it's no longer a concern for me. I don't give a damn about Xilinx any more. I've just got the CD with Altera's Quartus for Linux and it's all normal tarballs, which I have unpacked just fine manually without using any installer. Then after giving it a bootleg license file I've got the command line tools working. So, reiterating for those who haven't caught the gist - I now have working command line tools under Linux (no Winblows, no GUI, no X display needed) for compiling Altera FPGAs. I start with Verilog sources and get an SOF (SRAM object file) for the FPGA, all command line controlled by a Makefile, just like compiling C code with cc under UNIX. Isn't this something to celebrate? MS

18 years, 9 months

Tandy Xenix Boot Disk

by kelly＠catcorner.org

> From: Chuck Guzis > Sent: 10/27/2005 2:40 AM > Subject: Re: PC Ephemera > > Way OT: Does anyone have a Xenix boot disk for a TRS-80 Model 16? > Does it require a hard disk or can you run with the two floppies? > > Cheers, > Chuck Do you want a copy of one of the original disks? I have version 3.1, but that requires a PAL update to the 68000 board. I MAY have version 1.1 or 1.3 around somewhere. Do you want 5.25" or 8" media? As long as you have the 68000 board and memory intstalled, you can boot with a floppy and a file system diskette, but you don't have many of the tools. What are you trying to do? I loved the diskutil, but that doesn't actually require loading Xenix. If you have a later generation hard drive controller in your machine, you can probably use just about any RLL/MFM interface drive to get going. If you don't then If you have the middle generataion (without the red bus lines), you'll need the external primary drive case with a working 12 meg or larger MFM drive installed. Kelly

18 years, 9 months

US Sources for old ICs

by tshoppa＠wmata.com

Brent wrote: > Across the history of ICs, DIP packaging begins to look like a > 25-to-30-year sidebar. I like the way "flip chip" (not just the term, but the concept) is coming back into vogue, forty years after DEC registered it as a trademark. Tim.

18 years, 9 months

US Sources for old ICs

by tshoppa＠wmata.com

William Donzelli wrote: > Ever notice that in the 60s and 70s, they did not use flatpacks all that > properly? For some reason, the philosophy was to have the leads quite > long. No real reason for that, is there? The "official" way of mounting flatpacks also required you to mill a chunk of the board away so the IC sits in the PCB, and then you have to weld (not solder) the leads to the PCB. Maybe in the 60's it made sense but with multilayer boards today getting rid of all those signal traces (as well as the ground and power planes!) just won't fly. It's possible that the long leads had somethng to do with welding them. I got the impression that flatpacks weren't about increasing density but were an over-reaction to problems with hermetic seals and bent leads. Tim.

18 years, 9 months

Z80 Telescope Controller (was Homebrew newsgroups / forums?)

by ajp166＠bellatlantic.net

> >Subject: Z80 Telescope Controller (was Homebrew newsgroups / forums?) > From: gtulloch at shaw.ca > Date: Wed, 26 Oct 2005 23:36:51 -0500 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >Well, ok, in that case ... > >I'm building a Z80 based microcontroller as a telescope controller, to >run a few stepper motors, calculate and correct for periodic errors as >well as XYZ errors in the mount. The driver circuit is done >(http://www.bbastrodesigns.com/cot/steppercircuit.html), and >currently runs off a DOS app which uses the parallel port to pulse >the motor windings. However, I prefer not to use a dedicated >DOS PC so I'd like to put a Z80 in front of the driver with an RC >circuit connected to the NMI so I know how long the duration between >interrupts is and can thus calc the steps required to track. For historic >reasons the code will be written in FORTH - a PC connected via serial >will do all the heavy lifting as far as telling the Z80 where to point >and how. Comments on the veracity of this architecture welcome! RC circuits drift with temerature and voltage, not an accurate source of time or position information. A better whay uses a timer chip like the Z80 CTC or 8253. Though a PIC or other micro(8048, 8051) usually has a timer counter on board. Generally speaking using a micro as a morot controller is commmonplace. The real trick is being able to start at a calibrated point and return back to it (resetability) as well as move to any point with accuracy. So beside the mechanical problem of movement there are the issues of knowing where you are or at least where the start point is. >I have a few questions I'm hoping someone can answer for me, starting >with the following: I have a Z80A and a 4 mhz TTL clock >oscillator - I'm wondering if it would be ok to connect the clock >directly to the CPU or is it wise to connect it via a parallel or >serial resonant oscillator circuit like those described here: Yes, you can if CMOS, if not then add a 330 ohm pullup resistor. The Z80 requires a clock that swings closer to ground and Vcc than all the other pins. >http://www.z80.info/uexosc.htm > >Why be so elaborate? The data sheets for the oscillator doesn't say >"Make sure you connect via a parallel or serial resonent oscillator >circuit!" Because most digital hackers would not know what it is maybe? A parallel or series resonant osc refers to the whay the crystal is connected in and used. The inportant thing is to meet the rise and fall times as well as the logic high and low voltages that the Z80 requires. and that wasn't addressed well there. >Thanks for any light you can shed on this, Google hasn't been helpful. >I have references that do it both ways without explanation so I'm >confused! If google isn't helpful then you asked the wrong question. There is literally mountains of z80 information out there. Allison

18 years, 9 months

Homebrew newsgroups / forums?

by gtulloch＠shaw.ca

Hi all: I'm building a Z80 based computer as a stepper motor controller, and it would be nice if there was a homebrew newsgroup to ask questions on since I don't think this is the group to do so - any recommendations? Yes, I know I'm 30 years behind the curve, and yes, I know a microcontroller would save me some time, but where's the fun in that? Regards, Gord

18 years, 9 months

[Fwd: PDP-11 Collection for Sale]

by bottlcaps＠gmail.com

Forwarded from vmsnet.pdp-11 with permission by poster -------- Original Message -------- Subject: PDP-11 Collection for Sale Date: Tue, 25 Oct 2005 09:02:57 -0400 From: Will Kranz <will_kranz at softhome.net> Organization: Info-PDP11<==>vmsnet.pdp-11 Gateway Newsgroups: vmsnet.pdp-11 Gentlemen: My dad passed away over the weekend. He has be acquiring 11/23 systems and componets for something like 25 years. Its time to clean out the basement. I don't want to give things away, but do want some of this to go to good homes where I know it will get the love and care that it deserves. I thought I'd give you guys the opportunity before posting anything on Ebay. I'm starting a web page where I will attempt to maintain a list of equipment: http://www.fpns.net/willy/pdp11/forsale.htm The stuff is located in Darien, CT just off I-95. You'd have come pickup or arrange shipping as I do not have the energy for it. Please make me an offer I can't refuse. Use the email address above, or the contact information on the web page. Be well, Will -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.1.361 / Virus Database: 267.12.5/147 - Release Date: 10/24/2005 ---------- To unsubscribe (or subscribe) from (to) this list, send a message to info-pdp11-request at village.org, with the first line of the message body being "unsubscribe" or "subscribe", respectively (without the quotes).

18 years, 9 months

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test-drb October 2005