October 2005 - test-drb@ccmp.vtda.org

by msokolov＠ivan.Harhan.ORG

Cameron Kaiser <spectre at floodgap.com> wrote: > Yeah, but if it wanted libX for the installer and you don't have it, even > if you could bypass it, the odds are pretty freaking good that the main > program would require libX also. There is more than one "main program". There are command line tools that do the real work and a GUI front end for them. I only care about the former, I'm fine with never being able to run the latter - I don't need no fucking sissy GUI shit. MS

20 years, 7 months

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It figures! (broken 9-track)

by ard＠p850ug1.demon.co.uk

> > Well, it figures. I was bragging on the list about how great my 9 track > worked with the DQ132, and the power supply blows. I turn it on now, and no > lights, nothing. > > Anyone have a clue what might have gone? I was away when it happened. The > PDP11 was off, and I had left the 9 track on, plugged into the power > control. > > The unit is an Overland OD3201. There is no external fuse. NEver having seen this unit, I can't offer specific help, but I would at least start by opening it up. Look for _intenral_ fuses, check them, but don't necesarily replace them if they're blown. You do want to see how violently they belew -- if the glass is shattered or blackened by a film of metak, then the the thing really took some current! It would also be useful to know if this is a switching supply (look for electrolytics rated at 200V or more), or a linear (is there a large laminated-core transformer?). And what the main components, espeically ICs, are. -tony

20 years, 7 months

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PC Ephemera

by swtpc6800＠comcast.net

Adrian Graham wrote >> I'd have thought this was worth saving if it's related to the 5150 XT, or >> at >> least it is to me. I'm trying and failing miserably to find an XT with a >> 64K >> motherboard, purely because I guess people upgraded them as soon as they >> could afford to. I had a original IBM PC with the 64k motherboard and small power supply. A friend bought an XT as soon as they came out and it had the 256k motherboard. I don't think they ever made a 64k XT. Later I had my BIOS upgraded to install a 20 MB hard drive. (And a power supply upgrade.) I had to take my computer to an authorized IBM dealer to get the BIOS swapped. They would not just send you a ROM. Even with an AST 6 Pack I did not have 640kB or RAM because of the 64k motherboard. (But I did have a cassette interface.) Michael Holley

20 years, 7 months

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Chicago-area DECies?

by ISC277＠CLCILLINOIS.EDU

Hey, I was just wondering if any of my fellow DECies on this list live in the Chicago area, I know there were quite a few DEC shops around here back in the day.

20 years, 7 months

2
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It figures! (broken 9-track)

by ISC277＠CLCILLINOIS.EDU

Well, it figures. I was bragging on the list about how great my 9 track worked with the DQ132, and the power supply blows. I turn it on now, and no lights, nothing. Anyone have a clue what might have gone? I was away when it happened. The PDP11 was off, and I had left the 9 track on, plugged into the power control. The unit is an Overland OD3201. There is no external fuse. TIA Julian

20 years, 7 months

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Recall: It figures! (broken 9-track)

by ISC277＠CLCILLINOIS.EDU

Wolfe, Julian would like to recall the message, "It figures! (broken 9-track)".

20 years, 7 months

1
0
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It figures! (broken 9-track)

by ISC277＠CLCILLINOIS.EDU

Well, it figures. I ws bragging on the list about how great my 9 track worked with the DQ132, and the power supply blows. I turn it on now, and no lights, nothing. Anyone have a clue what might have gone? I was away when it happened. The PDP11 was off, and I had left the 9 track on, plugged into the power control. The unit is an Overland OD3201. There is no external fuse. TIA Julian

20 years, 7 months

1
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chipset pinout wanted for 82C206.

by jpero＠sympatico.ca

Googled and can't find a datasheet. Seems the payware website had cleaned out the websites where you can access datasheets before. What I needed: typical schematic or description of CMOS battery back up 3.6V rechargeable with 4069 IC and 82C206 (SiS, UMC, OPTi and C & T uses this 82C206) specifically chipset's pin number for battery back up to retain data and run clock. I'm trying to troubleshoot typical motherboard that is not holding CMOS data even I do have 3.6V battery power (already checked). Cheers, Wizard

20 years, 7 months

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Comment on 'boardswapping' as part of the computer CULTURE.

by marvin＠rain.org

Board swaping and component replacement both have their place and that place depends on your particular philosophy and goals. For myself, I look at component replacement as a way actually learning how things work instead of shotgunning a problem until it appears to have been solved. Actually understanding how something works leads to progress while I *firmly* believe that the board swapping only mentality leads on a spiral path downwards. Board swapping is the obvious answer to the time problem of reducing downtime ... most of the time :). A good analagy that most of us have run into is the "my son/daughter/friend/??? is an expert with computers and can fix anything." Most of these people are called experts *only* because of they know a bit more than the person making the comment. Knowing how to reformat and reinstall an OS has its place, but without knowing what is going on, it is really easy to reinstall the same problems that generated the "Oh, you need to reformat the HD ..." And Tony's comment about "that's the way things are done ..." is a great statement that I fully believe in and support!!! A sad (to me anyway) commentary on people in the US are the number of people who prefer to buy an assembled and tested unit instead of building it themselves when given an option. On Fri, 21 Oct 2005, Tony Duell wrote: > > Boardswapping has a place and is a legitimate part of the history of > > computers going way, way back. It is how things were and are done, and > > I have never found 'that's the way things are done' to be a sufficient > reason for carrying on doing them that way. If you can prove that your repair business model would be more successful than the one that has evolved over time in the electronics industry then you should write a book and become a consultant and make millions. Why waste your breath with a bunch of geeks like us? -- Sellam Ismail Vintage Computer Festival

20 years, 7 months

3
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FPGA VAX update

by msokolov＠ivan.Harhan.ORG

Cameron Kaiser <spectre at floodgap.com> wrote: > That you, basically, stole the software? I didn't steal it, I forcibly liberated it for the People. And there was much rejoycing. MS

20 years, 7 months

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Pre-VCF meetup, anyone?

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/

20 years, 7 months

1
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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.

20 years, 7 months

2
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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 >> >

20 years, 7 months

1
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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

20 years, 7 months

3
2
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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

20 years, 7 months

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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.

20 years, 7 months

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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.

20 years, 7 months

1
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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

20 years, 7 months

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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

20 years, 7 months

7
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[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).

20 years, 7 months

2
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FPGA VAX update

by msokolov＠ivan.Harhan.ORG

Cameron Kaiser <spectre at floodgap.com> wrote: > What, because they used a *graphical* installer? No, because they encrypted the ZIPs to make it impossible to bypass said installer. MS

20 years, 7 months

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Apple II on Lost?

by spectre＠floodgap.com

I don't remember if this was already reported, but the underground hatch on tonight's repeat of Lost is apparently controlled by an Apple II (with an "execute" key). -- ---------------------------------- personal: http://www.armory.com/~spectre/ -- Cameron Kaiser, Floodgap Systems Ltd * So. Calif., USA * ckaiser at floodgap.com -- You are not ready! ---------------------------------------------------------

20 years, 7 months

1
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PC Ephemera

by ajp166＠bellatlantic.net

> >Subject: RE: PC Ephemera > From: Fred Cisin <cisin at xenosoft.com> > Date: Wed, 26 Oct 2005 19:12:18 -0700 (PDT) > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >On Wed, 26 Oct 2005, Chuck Guzis wrote: >> Not AFAIK. It was very difficult to buy the "bare" PC retail, what with >> demand being as strong as it was. Most units were sold with at least one >> 160K floppy. > >prob'ly mostly because they were charging about $500 for a Tandon TM100-1! >(and a few hundred $ for each row of 16K RAMs) > >In fall 1981, I was able to buy a bare 5150, plus FDC and CGA. >I had plenty of RAM and floppies in stock for TRS-80s. > >I wasn't able to get another bare one until summer 1982. > >By 1983, the college where I teach was buying that configuration a dozen >at a time. > >> I can recall trying the interface out and saying "yes, it works", but the >> most useful aspect of it was the motor control relay. > >Yep! >I used it just long enough to confirm that it would not be a good way to >distribute software. Harrumph! I'd given up in "audio cassette interface" back in 1976 as mostly useless. I was rolling on the floor laughing when I got to see the "PC" and it has the bit bash trash cassette interface. That was a definate "you gotta be kidding right?" moment. Why laugh? My desktop had a multibus 8086 system running at 8mhz with a full megabyte (no rom holes) and four 8" DSDD (NEC!) drives in the spring of 1982. Allison

20 years, 7 months

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BA11-Sx support brackets needed

by fireflyst＠earthlink.net

Hey everyone, I'm in need of one or more sets of support brackets for a BA11-S box cover...you know, the two black ears that go off the rear of the cover and mount to the back of the chassis. Let me know if you have 'em to part with... Julian

20 years, 7 months

1
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PC Ephemera

by ajp166＠bellatlantic.net

> >Subject: RE: PC Ephemera > From: "Richard A. Cini" <rcini at optonline.net> > Date: Wed, 26 Oct 2005 21:50:49 -0400 > To: "'General Discussion: On-Topic and Off-Topic Posts'" <cctalk at classiccmp.org> > >I actually have one of these. My wife's uncle worked at IBM and bought the >PC and the expansion unit "way back when". It was a PC case with a backplane >and the interface card, connected by a 3' shielded cable which IMHO was way >too stiff for normal use. This unit has a 20mb hard drive in it and the last >time I used it (3-4 years ago) it worked fine. > >If $2850 was the original price, that's a rip off. It's an empty PC case, a >backplane, power supply and an ISA card. $400 in parts at the most. Well in 1983 a SA400L was still a 199$ item, The "kit" from intel (8284A, 8088, 8255, 8253 and 8259) was 12$/Q10,000. DRAMS 64K were still up the price curve 8$/10,000. Large Eproms 8Kx8 2764 or the big 27128 were not cheap either. The raw 765A was around 5$/Q1000. The board was covered with TTL and a few PALs. Monitors were over 100$ for monochrome and color was around 400$. Yes, they were stinking expensive. Then again at the same time even a NS* machine loaded (48k two drives, no hard disk) was around 1600$. Allison

20 years, 7 months

1
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VMS drive cleanup assist

by compoobah＠valleyimplants.com

I'd look at Darik's Boot and Nuke (dban.sourceforge.net) Based on Linux which, while not classic, has good support for Alpha AXP, and DBAN has credibility. build one for AXP and use it. Sadly, being Linux based it won't run on many classic systems (e.g. VAXen, PDPs, . . .) but it's possible that someone could do an xBSD port.

20 years, 7 months

1
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US Sources for old ICs

by cclist＠sydex.com

The chat about the FDC reminded me of a data acquisition project I've had partly completed for a couple of years. Where is a good source for purchasing small-quantity ICs in the US? In particular, I'm looking for a few 64Kx9 async FIFOs (e.g. IDT7208 or CY7C466) in DIP packages (I can find the Cypress part at DigiKey, but only in QFP). Suggestions would be welcome. Cheers, Chuck

20 years, 7 months

8
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RL01 drive select plug and power supply questions

by ajp166＠bellatlantic.net

> >Subject: Re: RL01 drive select plug and power supply questions > From: Johnny Billquist <bqt at Update.UU.SE> > Date: Fri, 21 Oct 2005 13:16:33 +0200 (CEST) > To: cctalk at classiccmp.org > >On Thu, 20 Oct 2005, Allison <ajp166 at bellatlantic.net> wrote: > >> >Subject: Re: RL01 drive select plug and power supply questions >> > From: David Betz <dbetz at xlisper.mv.com> >> > Date: Thu, 20 Oct 2005 18:26:02 -0400 >> > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> >> > >> >Thanks for your reply. I guess I'm okay with power even if I leave in >> >the DHV11 as it seems my BA11-N has been upgraded to a H7861 power >> >> Unless you need the IO I'd pull it anyway. The system will run cooler >> and I doubt you have need for the lines. DHV11 is a MUX and you need >> the chassis kit to break out all the serial lines. Most OSs for PDP11 >> don't use it (system build time option) and the DLV11J is easier to use >> and program. The DHV11 cannot be used for a console either. > >I think I'll slightly disagree with you here. >While all you say is essentially true, the DLV11 is a tremendour burden on >the system compared to the DHV11. So if you actually want to run serial >connections to a machine, keep the DHV11, and don't use the console more >than absolutely neccesary. > >Big difference between DMA and interrupts you know... Yes I do. However for a single user system the load is not an issue. If your running a timeshare system such as RSTS or RSX with more than one user then DHV11 sense as well. For most of my 11s four lines is the limit for what I can seem to keep busy. Figure a user terminal, LA100 Printer and serial line for modem or data line to another system. At the extreme I've run two terminals for OSs that support that but, I can only type on on at any instant. ;) Allison

20 years, 7 months

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US Sources for old ICs

by Richard.Cini＠wachovia.com

I use BG Micro a lot for some older semis, including plain "S" TTL ones and various SRAMs. -----Original Message----- From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Paul Koning Sent: Wednesday, October 26, 2005 11:31 AM To: cctalk at classiccmp.org Subject: Re: US Sources for old ICs >>>>> "Chuck" == Chuck Guzis <cclist at sydex.com> writes: Chuck> The chat about the FDC reminded me of a data acquisition Chuck> project I've had partly completed for a couple of years. Chuck> Where is a good source for purchasing small-quantity ICs in Chuck> the US? In particular, I'm looking for a few 64Kx9 async Chuck> FIFOs (e.g. IDT7208 or CY7C466) in DIP packages (I can find Chuck> the Cypress part at DigiKey, but only in QFP). Jameco tends to have the older stuff in the older packages. They still sell 4116s, for example, and 7400 series (plain 7400, not the 74ABCDEF00 newfangled variants). paul

20 years, 7 months

2
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US Sources for old ICs

by ajp166＠bellatlantic.net

> >Subject: Re: US Sources for old ICs > From: Paul Koning <pkoning at equallogic.com> > Date: Wed, 26 Oct 2005 11:43:57 -0400 > To: cctalk at classiccmp.org > >>>>>> "Joe" == Joe R <rigdonj at cfl.rr.com> writes: > > Joe> The small surface mount only packages are a BIG problem for > Joe> individuals that want to build a single circuit. A friend of > Joe> mine designs and builds a lot of circuits commercailly and he's > Joe> always raising hell with the IC manufacturers and trying to get > Joe> them to produce chips in DIP packages. I keep telling him that > Joe> it's hopeless. > >There's at least one company that builds SMT to DIP adapters, so you >can plug SMT packaged chips into DIP prototyping systems and the like. > >Of course manufacturers don't want to use DIPs. They are electrically >inferior. For that matter, they are also obsolete -- if they made DIP >packaged chips they would certainly be very low volume products. > >I understand the preference for DIPs in amateur work, though SMT isn't >really all that hard. But I can't imagine any reason for wanting DIPs >in new commercial designs. They are bigger, slower, not RoHS >compliant, ... > I prefer the larger SMT parts but I don't get worked up if what I get is what I can get. At upper HF and VHF/UHF SMT is the way to go even if your doing deadbug (ugly over groundplane). Allison

20 years, 7 months

1
0
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US Sources for old ICs

by ajp166＠bellatlantic.net

> >Subject: Re: US Sources for old ICs > From: Paul Koning <pkoning at equallogic.com> > Date: Wed, 26 Oct 2005 11:31:08 -0400 > To: cctalk at classiccmp.org > >>>>>> "Chuck" == Chuck Guzis <cclist at sydex.com> writes: > > Chuck> The chat about the FDC reminded me of a data acquisition > Chuck> project I've had partly completed for a couple of years. > > Chuck> Where is a good source for purchasing small-quantity ICs in > Chuck> the US? In particular, I'm looking for a few 64Kx9 async > Chuck> FIFOs (e.g. IDT7208 or CY7C466) in DIP packages (I can find > Chuck> the Cypress part at DigiKey, but only in QFP). > >Jameco tends to have the older stuff in the older packages. They >still sell 4116s, for example, and 7400 series (plain 7400, not the >74ABCDEF00 newfangled variants). > > paul JDRmicrdevices get the catalog. Oddball stuff like the CY466 won't be there but TTL and CMOS generic logic is. For the oddballs maybe >from Digikey or Mouser. Allison

20 years, 7 months

1
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VI-90 and VG920 terminals?

by wulfcub＠gmail.com

I recently stumbled across an odd set of emulations available in the controller for a printer I have. This system was introduced in the early 80's, and was only recently EOL'd by xerox (the 4090LPS). The default terminal emulation is ADM3, which works well with the Link MC5 terminals. ADM11 is also available, along with VI-90 and VG920, which I've never heard of. To make life a little bit easier while playing with this beast, I would like to tie it to a pc (linux or windows). Changing the system directly is not really an option, as the whole thing is a very bizarre setup, based loosely on DEC architecture. The question is, does anyone know anything about the VI-90 or VG920 terminal emulations? And, does anyone know of a way to directly emulate an ADM3 or ADM11 terminal under linux or windows? (via serial, of course) The system has many options available, including: a scsi tape drive option (I have the equipment, but it's another xerox oddity to run), a shared-disk interface option, ethernet (early implementation for thicknet), a 9-track tape drive (I have, and use, this one), an "online" (bus & tag channel-attach) interface, which I also have. It's an odd, and interesting, system. >From what I've been told, the entire thing was written in RAD50. It can carry, total, about 512M of mem, spread across the various subsystems (Main, Font, Graphics), all on individual chips, nothing socketed, lots of blinkenlights. Anyone wanting more info (or even an entire controller!) just ask! --Shaun -- "If you live to be a hundred, I want to live to be a hundred minus one day, so I never have to live without you." -- Winnie The Pooh http://www.lungs4amber.org

20 years, 7 months

2
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FPGA VAX update

by msokolov＠ivan.Harhan.ORG

Eric J Korpela wrote: > Xilinx used to have software that would run under Solaris... woodelf <bfranchuk at jetnet.ab.ca> wrote: : They could indeed. All I know is the free?/low cost software is : windows based : and the hi-priced software is windows/other. I suspect they think if : you are not : using a Pee Sea you have $$$ to shell out for software. Xilinx' free download is available for Winblows and for Linux. I have downloaded the Linux version, but ran into a brick wall installing it. The downloadable package is actually a .sh file that constitutes a /bin/sh script with binary data following it (I know, a totally crazy arrangement, but I didn't look more closely into how it actually works due to lack of interest in this manure). When you run it, it unpacks into a bunch of other files. Those consist of an installer executable and a bunch of files for it to unpack. When I saw that the latter were ZIPs, I thought I would just extract them manually, but not so fast - they are encrypted!!! The fuckers are forcing the use of their assinine installer, which is of course not runnable. Attempting to run it produces a complaint about missing libXm.so.3, i.e., it's some fucking GUI thing. I didn't even bother finding, downloading and compiling whatever package would provide that libXm.so.3, since the next thing it would complain about of course would be that I have no X display. And if I turned inside out to give it the goddamn X display it wants (that would require making a trip to my old facility, which would in turn require borrowing a friend for the duration of the entire procedure since I don't feel safe going there alone [it's a terrible neighbourhood], and none of my friends have that kind of spare time), I'm sure there would be something else that would make it unhappy and it still won't run far enough to unpack the fucking encrypted archive. In short, Xilinx has done more than enough to deserve the death penalty under Galactic law. They are badly in need of a date with Madame La Guillotine. Fortunately, I may have found an alternative solution using Altera. Not that Altera is any better, but the company for which I'm currently doing a consulting project involving FPGAs uses Altera, and I've got Quartus (Altera's SW) for Linux through them. I haven't seen it yet actually, I've just got an E-mail from the boss saying that the CD is on my desk for me to play with tomorrow. So I'll look at it tomorrow. I'm hoping that I can install it on my Linux box at the company and then copy the installed files to my own one (i.e., pirate it). : Back to FPGA software for the VAX, I don't see the hardware a problem : but the software could be still be one. The small PDP'S has hoards of : paper tape : software, the big ones all need a OS. The OS is not a problem - I am the maintainer of the one true OS for the VAX (which is of course 4.3BSD-Quasijarus). MS

20 years, 7 months

4
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Looking for an 8 bit FDC...

by ajp166＠bellatlantic.net

> >Subject: Re: Looking for an 8 bit FDC... > From: Dave Dunfield <dave04a at dunfield.com> > Date: Tue, 25 Oct 2005 23:28:30 -0400 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >Have you tried just using the diskette controller in a PC? - I've >found that almost all of my P1ish machines can read/write FM, and >I've used ImageDisk to backup and restore almost all of the soft- >sector formats that I have here (although some are better than others. >I've found that Intel mainboards work very well, although the ones >I have only support one drive select). Again an older 486 and an AT (older) FDC is a hard solution to beat for the majority. Amazing how an relatively easy 80% solution covers 97% of the need. A PC controller isn't a complete solution but for a huge amount of day to day effort it's a usable solution. Those disks that cant be read with that solution are already known. Those bad actors are either hard sectord where each is likely a special case or sufficiently odd enough to warrent keeping a sample system fully operational. The alternate is some system that has a bus so you can insert controllers to fit the oddball situations and just plug them in. I use S100 for that, right now the only formats that crate can't handle is the GCR formats (no systems here use it) and hard sector other than NS* though I do have an Altair hard sector system. The only problem that isn't solved however is they guy on the other side of the planet with the only other oddball system like it and needs a boot disk. I've have had this problem since I put a NS* conttroller in my first S100 system in '77. That problem is what I want is on brand Q media and format and I have brand N that doesn't do that. Allison

20 years, 7 months

1
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Looking for an 8 bit FDC...

by ajp166＠bellatlantic.net

> >Subject: Re: Looking for an 8 bit FDC... > From: "Chuck Guzis" <cclist at sydex.com> > Date: Tue, 25 Oct 2005 11:22:55 -0700 > To: cctalk at classiccmp.org > >On 10/25/2005 at 1:59 PM Allison wrote: > >>The 765A was least integrated but with the right external support more >>flexible than the 37C65 and later. > >You still have to put up with the "blindness' during the IAM interval and >the lack of support for MFM 128-byte sectors--and the lack of support for >non-standard address marks (not at all uncommon in old formats). At least >with the WD chips, you can read the raw track data. Ah huh, what? Who does 128byte MF sectors??? If you really have to it's possible to tell a 765 that it's a short sector in mfm. As to non standard address marks that was a tandyism and 765 "read deleted" works. >>>The data seperator was a fairly simple circuit and could be done with >>a counter or for improved results with a latch and prom. > >Or just find a nice little 8-pin WD 9216 data separator. If you wanted >more than that, a PLL might be the ticket. If you can find one 9216 is good or the 9229. IF not the latch/prom is a synthetic PLL (which is the logic in the 9216 etal) and very good with less headaches than a real PLL. In general a 765A on a late XT or early AT class FDC is the trick more possibilities than not. Those that it can't be require extraordinary effort. There are few reasons that seem to abound for do alls. Those be "archives" and I want to run a zzxxyy sim on a PC. Those that most often archive have a host that can read it. The other case is obvious. However, the case I run into the most is I wish to run ABC on Northstar* under CP/M and need to get it on to the AmproLB. For that the Ampro connected to the serial port of the NS* and MDM740 neatly sidesteps the "format problem" and once on the AmproLB I can run DOS and write it to a 720K 3.5" floppy under (DOS/WIN/NT/Linux) and run it under MyZ80 or whatever. Allison

20 years, 7 months

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Looking for an 8 bit FDC...

by henk.gooijen＠oce.com

Hi Jules, I replied yesterday evening, but somehow my e-mail did not show up (at least here). So, I resend it. Sorry if it hits the list a second time. I have a design that worked - 20 years ago, with a 1793. It has a PLL-based data separator, using a 72LS629 and 2 4-bit counters, IIRC. I need to look it up. It was interfaced to 6809 bus signals, so changing it for 6502 is straight forward. I recently bought a few 1793 chips from BGMICRO, and then decided to make my design a lot simpler by using a 2793 as that FDC has a data separator integrated. With the correct clock crystal selection you can use the hardware for 3", 3.5", 5.25" _and_ 8" drives (under software control)! I am working on a 2793 which is piggy-back connected to the "Blinkenlight" Core Board which is based on the 6809E and has more than enough RAM and EPROM on board. But that's just a matter of how you write the software how to read the floppy. For instance, sector-wise or track-wise as the 1793 and 2793 have read-track commands. I would not use DRAM chips, but takje a single static 32kx8. Saves work on soldering and room on the board. I started a webpage on this new project, see www.pdp-11.nl/ in the "my projects" folder. Vince still has Core Board kits (all parts included for $70), so the job is limited to the FDC part (and the software ...) But the Core Board is a 6809E instead of the 6502, I regard that's a plus !!! Handling double density will become tricky with the 6502, and even with the 6809, because of timing requirements (polling for DRQ is asserted). Single density can be handled by polling, but double density requires the use of IRQ or FIRQ or the use the SYNC instruction (need connect DRQ* to IRQ or FIRQ). I am waiting on the arrival of my 2nd BGMICRO order that has the 2793 ... gd luck, - Henk, PA8PDP This message and attachment(s) are intended solely for the use of the addressee and may contain information that is privileged, confidential or otherwise exempt from disclosure under applicable law. If you are not the intended recipient or agent thereof responsible for delivering this message to the intended recipient, you are hereby notified that any dissemination, distribution, or copying of this communication is strictly prohibited. If you have received this communication in error, please notify the sender immediately by telephone and with a "reply" message. Thank you for your cooperation.

20 years, 7 months

1
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FPGA VAX update

by msokolov＠ivan.Harhan.ORG

9000 VAX <vax9000 at gmail.com> wrote: > Altera supplies free "web" edition of its quartus II software too. I > am using that and I think it is as good as the linux one. But it's for Winblows only, isn't it? Dunno about you, but I'm not bringing a Winblows machine into the house, that's absolutely out of the question! Even Linux is right on the limit of what I can tolerate. MS

20 years, 7 months

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FPGA VAX update

by msokolov＠ivan.Harhan.ORG

woodelf <bfranchuk at jetnet.ab.ca> wrote: > From what I remember of Altera software , it brands itself to the > HD id or the network ID. I don't see how they can successfully do this under Linux, or any kind of UNIX. I guess they could try, but this "protection" would be laughable - a baby can get around this kind of "copyprotection". It ain't DOS or Winblows, it's Linux! I can intercept all system calls it makes, I can hack the kernel, I can do whatever I want to make it believe it's running on the machine it's "licensed" to. > Also I think you also may be stuck > with the GUI they use too. No, all the work is done by command line tools which the GUI calls, and the command line tools are documented. I'll use them as a backend for Icarus Verilog. MS

20 years, 7 months

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Looking for an 8 bit FDC...

by dave04a＠dunfield.com

>OK, I'm wanting to build a board with an 8 bit CPU (probably Z80, >possibly 6502) and a floppy controller IC on board with the intention of >hanging it off my PC (via serial or parallel, undecided yet) and >allowing me to read and write *most* formats from various 1980's 8 bit >micros... Funny, when I asked a few months ago if anyone was interested in collaborating on doing exactly this, I was practically run off the list with comments about how impractical it was, nobody would build it, and wouldn't a catweasel be ever so much better... So I let the idea drop (still might build one privately however). >Intel's 8271 looks like a possibility at the moment, but I thought I'd >poll the list for alternative ideas too. FM support is of course >critical - MFM is less of an issue as the host PC can handle that. > >I've never built any kind of computer from scratch, so it'll be a useful >experience. I figure on putting just enough code in ROM to support >downloading of actual firmware to the device over whatever the link is >to the PC, as that should save a lot of headache! > >Hopefully RAM requirements will be low enough that I can go the SRAM >route and avoid messing around with DRAM refresh (although IIRC the Z80 >has much of the necessary stuff built in...) I think the 8271 is pretty limiting ... I'd vote for a 1793 (or 2793 which has a bulld in data-separator) - it is used in a lot of classic systems, can handle a wide variety of formats, and can do raw track reads. A single 32k SRAM should be plenty to buffer a few tracks, which is really all you need. Have you tried just using the diskette controller in a PC? - I've found that almost all of my P1ish machines can read/write FM, and I've used ImageDisk to backup and restore almost all of the soft- sector formats that I have here (although some are better than others. I've found that Intel mainboards work very well, although the ones I have only support one drive select). Regards, Dave -- dave04a (at) Dave Dunfield dunfield (dot) Firmware development services & tools: www.dunfield.com com Collector of vintage computing equipment: http://www.parse.com/~ddunfield/museum/index.html

20 years, 7 months

2
1
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What is DECdatasystem?

by ajp166＠bellatlantic.net

> >Subject: RE: What is DECdatasystem? > From: "Julian Wolfe" <fireflyst at earthlink.net> > Date: Tue, 25 Oct 2005 22:02:48 -0500 > To: "'General Discussion: On-Topic and Off-Topic Posts'" <cctalk at classiccmp.org> > >So were these prebuilt systems versus built-to-configure systems? Mostly, more like limited menu systems. Aka if you need to do this than buy that. >In that case, that would make sense, just like the edusystem -8s. Very similar. Both were packaged with some options. Allison > >-----Original Message----- >From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org] >On Behalf Of Allison >Sent: Tuesday, October 25, 2005 9:28 PM >To: cctalk at classiccmp.org >Subject: Re: What is DECdatasystem? > >> >>Subject: What is DECdatasystem? >> From: "Wolfe, Julian " <ISC277 at CLCILLINOIS.EDU> >> Date: Tue, 25 Oct 2005 21:16:07 -0500 >> To: "'General Discussion: On-Topic and Off-Topic Posts'" ><cctalk at classiccmp.org> >> >>Okay, looking over the web, I've seen several PDP11 machines marked >>"DECdatasystem"... They don't seem to have anything in common...it's like a >>random marking DEC decided to put on machines. Anyone know what it means? > >The common thread of 'datasystem is they are bundled systems sold as >application solutions rather than "computers". > >It's part of DEC's history that Digital didn't sell computers, they sold >programmed data processors. that and quirky marketing. > >Allison >Ex Digit. > >

20 years, 7 months

1
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What is DECdatasystem?

by ajp166＠bellatlantic.net

> >Subject: What is DECdatasystem? > From: "Wolfe, Julian " <ISC277 at CLCILLINOIS.EDU> > Date: Tue, 25 Oct 2005 21:16:07 -0500 > To: "'General Discussion: On-Topic and Off-Topic Posts'" <cctalk at classiccmp.org> > >Okay, looking over the web, I've seen several PDP11 machines marked >"DECdatasystem"... They don't seem to have anything in common...it's like a >random marking DEC decided to put on machines. Anyone know what it means? The common thread of 'datasystem is they are bundled systems sold as application solutions rather than "computers". It's part of DEC's history that Digital didn't sell computers, they sold programmed data processors. that and quirky marketing. Allison Ex Digit.

20 years, 7 months

2
1
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What is DECdatasystem?

by ISC277＠CLCILLINOIS.EDU

Okay, looking over the web, I've seen several PDP11 machines marked "DECdatasystem"... They don't seem to have anything in common...it's like a random marking DEC decided to put on machines. Anyone know what it means?

20 years, 7 months

3
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Any own an 11/725...?

by technobug＠comcast.net

On Mon, 24 Oct 2005 05:00:57 +0100 (BST), ard at p850ug1.demon.co.uk (Tony Duell) wrote: > >>> The 11/730, of course, is mostly PALs (as I said) with some RAM as a >>> control store, 8 off 2901s as the ALU, and an 8085 (I think) to >>> load the >>> control store, etc. One day I am going to look into modifying the >>> microcode of that machine... >>> >> >> To what end? Increased performance? >> > > NO, just for fun... I doubt very much I could improve on the > performance > for running the VAX instruction set. I have not looked at the prints > carefully enough to determine how much of the instruction set is > hard-wired (if any), I wonder if it would be possible to run a > different > instruction set entirely. > > -tony > > Actually, with access to the micro instructions you can often substantially improve the run-time of a given program. The Modcomp II had the microbus accessible for use along with a number of unused instructions. The communications instructions and floating point were implemented using this bus. I implemented an instruction store attached to this bus and which allowed me to create and store new instructions. A friend working on a CS Phd in pattern matching ginned up a program that would find common instruction sequences in a program, deconstruct the microcode, perform optimization on the sequence and then create a new instruction which was substituted for the original sequence. We often got increases of performance of 20% over the original code. IIRC the Burroughs computers would load a different instruction set depending on what language was being used. Tony could create a VAX with Forth as the instruction set ;-) CRC

20 years, 7 months

4
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What is DECdatasystem?

by ISC277＠CLCILLINOIS.EDU

Okay, looking over the web, I've seen several PDP11 machines marked "DECdatasystem"... They don't seem to have anything in common...it's like a random marking DEC decided to put on machines. Anyone know what it means?

20 years, 7 months

1
0
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RX01 felt pad (Tim)

by tradde＠excite.com

--- On Tue 10/25, Tony Duell < ard at p850ug1.demon.co.uk > wrote: From: Tony Duell [mailto: ard at p850ug1.demon.co.uk] To: cctalk at classiccmp.org Date: Wed, 26 Oct 2005 01:11:34 +0100 (BST) Subject: Re: RX01 felt pad (Tim) > > Much easier on an RX01. I don't have to remove the drive. Remove > 3 screws from top board, and flip back. Remove 8 screws on lower > board and remove a few cables (remembering where they go) and lift > lower board and tilt towards back of unit. There thru two pretty > good sized access holes are the heads and all. I simply put a small The RX02 is like that too -- in fact the drives, chassis, PSU, front panel, etc are generally the same between the 01 and 02 (there is some issue of a resistor on the head connector, but...) But since the drive is so easy to remove (take off the fan plenum at the back, unplug the wiring, undo 6 screws, and it comes out downwards), I'd take it out. Access to the assembly is then a lot easier. -tony I'll remember this info for the next time I have to get to the heads or similar. Thanks. _______________________________________________ Join Excite! - http://www.excite.com The most personalized portal on the Web!

20 years, 7 months

1
0
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Looking for an 8 bit FDC...

by ajp166＠bellatlantic.net

> >Subject: Re: Looking for an 8 bit FDC... > From: Jules Richardson <julesrichardsonuk at yahoo.co.uk> > Date: Tue, 25 Oct 2005 19:14:52 +0100 > To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> > >Chuck Guzis wrote: >>>Intel's 8271 looks like a possibility at the moment, but I thought I'd >>>poll the list for alternative ideas too. FM support is of course >>>critical - MFM is less of an issue as the host PC can handle that. >> >> >> The 8271 is a pile of worms. Don't even bother with it. > >:-) > >> In a DIP package, if you want to restrict yourself to 5.25/3.5" MFM and FM >> (but not HD) formats, the WD 1770/1772 is a nice compact (28 pin) little > >I've certainly got 1770 chips lying around unused in the parts box... I >think you've just put that at the top of the list :) > >> Why a floppy to support your device, though? There are many high-speed >> interfaces available to choose from nowadays. Why not feed your device via >> USB? > >Rationale: > >I'm interested in doing this in order to archive old floppies to modern >media, and out of the 5 or so PCs I can lay my hands on at home, none >are happy with FM data :-( > >Catweasel's ruled out on grounds of cost, lack of schematics, and the >fact that it's an internal board anyway. > >I need an external box of tricks so that I can easily use it to do >archival work both at home and at the museum (and potentially other >locations too). I know the museum PCs have serial and parallel ports, >but not all of them will have USB; plus I'm hoping to spend zero cash on >this and just use parts lying around at home - I'll have various serial >& parallel I/O chips but certainly no USB stuff! > > > >As an additional thought whilst writing this (admittedly not thought >through yet!) serial might be nicer than parallel so that at some future >date I can dump all of the necessary firmware onto the disk interface >box's ROM and in theory just talk to it using a comms package from the >PC host. > >Lots more work in terms of understanding the various download protocols >to do it that way, and it means that the disk interface box needs to >understand the resultant disk image format on the PC which I'm not sure >I like... but it does mean that all the host PC needs is a serial port >and some comms software (which is covered by pretty much any modern-ish >PC OS on the planet) rather than any special application to drive the box. > >If serial's the standard interface though it'd be zero hardware changes >to support this in the future - it just means being stuck with a slower >serial protocol for disk image transfer, when parallel would be faster. >And yeah, I think we've been over this on this list before... :-) > >cheers > >Jules If you have an older box with ISA bus there is a direct solution.. Put a 1793/2793/1770 on a ISA protoboard and run it direct from the PC. Then all you need to write is software to make it go. There's absolutly no reason why you cannot do that. Allison

20 years, 7 months

4
4
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RX01 felt pad (Tim)

by tradde＠excite.com

--- On Tue 10/25, David Gesswein < djg at drs-c4i.com > wrote: From: David Gesswein [mailto: djg at drs-c4i.com] To: cctalk at classiccmp.org Date: Tue, 25 Oct 2005 18:22:26 -0400 Subject: Re: RX01 felt pad (Tim) I just took apart my RX02 to clean them since they were getting flakey. On a previous drive I just went to a craft store and bought the closest material I could find, cut it to a small dot to fit in the cup. Put a drop of glue in the cup and push the material in. To get the drive out for access. 1) Remove from outer shell if you have the desktop unit. The top cover comes off with obvious screws then ones along the side free the internal unit. 2) Disconnect the cables to the controller board and motor power connector on the back of the drive hidden by the air baffle. 3) Remove drive from rest of assembly. 2 screws through the air baffle at the back and 4 from the top down. If you tilt the upper board up on the hinge they are accesible through holes in the lower PCB. That should free the drive. You can then lift up the little presure arm to easly get at the pad. I don't have any real RX01's so they might be slightly different for disassembly. Much easier on an RX01. I don't have to remove the drive. Remove 3 screws from top board, and flip back. Remove 8 screws on lower board and remove a few cables (remembering where they go) and lift lower board and tilt towards back of unit. There thru two pretty good sized access holes are the heads and all. I simply put a small drop of contact cement on the holder and a very small amount on the pad. Let both dry for about 10 minutes. THen put the pad onto the bottom of the holder. Voila. It should work. Hardest part was keeping the little pad on my finger to stick it to the holder. It kept falling off. It's setting up now. I will test it later. Thanks all. Tim R _______________________________________________ Join Excite! - http://www.excite.com The most personalized portal on the Web!

20 years, 7 months

2
1
0 0

Looking for an 8 bit FDC...

by julesrichardsonuk＠yahoo.co.uk

OK, I'm wanting to build a board with an 8 bit CPU (probably Z80, possibly 6502) and a floppy controller IC on board with the intention of hanging it off my PC (via serial or parallel, undecided yet) and allowing me to read and write *most* formats from various 1980's 8 bit micros... Intel's 8271 looks like a possibility at the moment, but I thought I'd poll the list for alternative ideas too. FM support is of course critical - MFM is less of an issue as the host PC can handle that. I've never built any kind of computer from scratch, so it'll be a useful experience. I figure on putting just enough code in ROM to support downloading of actual firmware to the device over whatever the link is to the PC, as that should save a lot of headache! Hopefully RAM requirements will be low enough that I can go the SRAM route and avoid messing around with DRAM refresh (although IIRC the Z80 has much of the necessary stuff built in...) cheers Jules

20 years, 7 months

5
7
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RX01 felt pad (Tim)

by djg＠drs-c4i.com

I just took apart my RX02 to clean them since they were getting flakey. On a previous drive I just went to a craft store and bought the closest material I could find, cut it to a small dot to fit in the cup. Put a drop of glue in the cup and push the material in. To get the drive out for access. 1) Remove from outer shell if you have the desktop unit. The top cover comes off with obvious screws then ones along the side free the internal unit. 2) Disconnect the cables to the controller board and motor power connector on the back of the drive hidden by the air baffle. 3) Remove drive from rest of assembly. 2 screws through the air baffle at the back and 4 from the top down. If you tilt the upper board up on the hinge they are accesible through holes in the lower PCB. That should free the drive. You can then lift up the little presure arm to easly get at the pad. I don't have any real RX01's so they might be slightly different for disassembly.

20 years, 7 months

2
1
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FPGA VAX update

by technobug＠comcast.net

On Tue, 25 Oct 2005 20:35:37 +0100 (BST), > ard at p850ug1.demon.co.uk (Tony Duell) wrote: > > Incidentally, the PALs in the 11/730 are 'protected by solder'. > That is, > the security fuses are intact. If you are prepared to desolder them > from > the PCBs, you can read them out. > > -tony At one time I had a set of prints for the 11/730 and IIRC the PAL codes were included on the schematics. CRC

20 years, 7 months

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test-drb October 2005