test-drb January 2001

test-drb@ccmp.vtda.org

181 participants
415 discussions

by ajp166＠bellatlantic.net

-----Original Message----- From: Jim Battle <frustum(a)pacbell.net> >For instance, the first version of the emulator would convert each >windows keystroke into an emulated "strobe" of a keystroke register. >But then my first user noted a discrepancy in a program he tried. > >After thinking about it a little bit, we realized that the difference was >because the real Sol generates an approximately 6 us strobe when >a key is hit, asynchronously setting a "key ready" flop. If the processor >polls this register, the flop gets cleared, but if it polls it before the >6 us strobe is finished, then reading it doesn't clear the flop since >the async strobe has priority. Thus, one keystroke can appear twice >in these circumstances. This is an oddity but remember the 8080 is 2mhz (5us for an INP insturction) so this only can occur if the buffer read should occur within 6us of the status read. Typically the code is something like this: keywait: INP status ani keyflag JNZ keywait ; back to top may be a JZ INP keydata ... The delay from the first input to the second is 10+7+7 (24 cycles or 12uS) if the J(n)Z is not taken and much more if it is so the race condidtion it typically not a problem. It could be if someone was reading keystokes on the fly something bad can occur but not reading the key pressed status first is bad programming. After looking at the drawing It appears the Key ready goes to a JK flop /K input and is not async as the data (strobe) is loaded on the falling edge of Phase2 clock. So the behavour observed is unlikely and the read/clear has precedence. While Phase2 occurs once every ~500ns it is possible to clear and reset making the key buffer hold what amounts to bounce (read twice). Also the Osc used for the 3uS clock in the keyboard is a TTL RC thing that likely has a +-25% error (times two as it's divided by 2) adding to the already long strobe. In the end it would take a pathological programming case to make that keyboard behavour show. >One thing I'm planning on adding is intermittent disk errors -- the reason >is that I want to eventually rewrite my CP/M BIOS and I would >rather test it on the emulator. Without failure simulation, then too >much of the BIOS would go untested. The assumption is the bios has error retry, many early bios did not. You got an error and the system you give you retry or ignore both usually fatal if bad data was read. Some of the early 8251 serial (UART) devices had a timing thing that could cause the reverse action. Never assume all devices are infinitely fast compared to the cpu. >Now for an example of behavior I'm not going to bother with. >The Sol keyboard has infinite key rollover. On my PC, either the >keyboard or the driver stops giving KEYDOWN messages after >about four keys are down. Perhaps there is some way to get that >extra info, but I'm not going to bother. I don't see any reason to >emulate that extra behavior, so it won't go in. No it didn't. The encoder may have had Nkey rollover but it was anything but infinite. There was at best one byte of buffereing. If you read the buffer fast enough you can stay mostly ahead of it but most software of the time didn't buffer what it got so the last key read was it. Allison

25 years, 4 months

Nuke Redmond!

by frustum＠pacbell.net

At 07:10 PM 1/10/01 -0500, THETechnoid wrote: >I'm running and have been running OS/2 since I got my first clone PC in >1992. Never did Windows but for servicing it for others. I just bought >EcomStation, the latest version of the OS/2 operating system from Serenity >Systems. Surely you must see the contradiction is having such an extreme position on Microsoft and using an OS that was originally written by the same company. I'm sure it has evolved quite a bit since MS gave up control of it to IBM in 1990, but if you take out the OS/2 box that you were using in 1992 I'll bet you can still smell Bill's greasy fingers on it. No, to be really clean, you should be using a different OS. Yes, something more unix. Ignore these johnnies come lately, go to the true innovator, the first unix on a PC: run Xenix. Damn. Microsoft did that one too. Here's a link with a pretty extensive timeline of MS OS developments: http://www.powerload.fsnet.co.uk/timeline.htm ----- Jim Battle == frustum(a)pacbell.net

25 years, 4 months

Tek 2230 'scope check-out

by mcguire＠neurotica.com

On January 10, Mike Ford wrote: > >Last summer I picked up a Tek 2230, a 100 MHz two-channel > >digital storage oscilloscope. > > > >I think I'd like to check it checked out by a repair > >service to confirm whether all its functions are working or not. > > Why? I am guessing you will be out $50 to $100, and thats assuming its fine > and needs no "adjustment". > > I would just use it, wouldn't most problems be fairly obvious? This is a good point, especially with a DSO. Except for the analog stuff in the very front-end...isolation, maybe a preamp, and some attenuator hardware...the only things that I can think of in most simpler DSOs that might require adjustment would be the time base and the sweep alignment & linearity stuff. Tek DSOs are pretty solid; I'd bet that, if it's basically functional, it's in good shape. -Dave McGuire

25 years, 4 months

Apple external SCSI drives

by dhquebbeman＠theestopinalgroup.com

> On Tue, 9 Jan 2001, Louis Schulman wrote: > > > OK, here is a very elementary question that has always > > stumped me. Is there any difference between an external > > SCSI hard drive made for a Mac and a generic SCSI hard > > drive? Can I hook up a Mac SCSI hard drive to some other > > computer with a SCSI interface and expect it to work (after > > formatting, of course)? What about the other way around? > > The first alternative works very well indeed. The second won't, though. > Macs use hard drives with a particular Apple firmware, without which HD SC > Utility won't recognise the drive. Bloody stupid. Another Apple > peculiarity would be its lack of support for remote start in > SCSI, so the hard drives will need to jumpered for automatic start on > power, but this won't affect other systems. Non-Apple drives work quite well with Macs; however, while your observation about the use of Apple's HD SC Utility is correct, all non-Apple SCSI drives sold *FOR* the Mac come with their own SCSI setup utility. For a SCSI drive *NOT* sold _for_ a Mac, you'd need a third-party toolkit like FWB' Hard Disk Tools (or whatever it's called). I've used it to add IBM and DEC SCSI drives to a Mac. regards, -dq

25 years, 4 months

Amstrad PC1640HD20

by pete＠dunnington.u-net.com

On Jan 10, 16:09, Lawrence Walker wrote: > One of my ST mouses (mice ?) has a simple switch to change it > to an Amiga mouse. I also have a Kraft joystick with DE9 and > DB15 connectors and a switch to change between Apple IIe and > PC. There was a box from Practical Peripherals called Mouse- > Master to switch between STs and Amigas. Seems like it shouldn't > be too difficult to make an all-purpose connection box for different > platforms. I also have a 4+4-input 1+1 output ABCD box, to use a > single mouse and K-B with multiple systems, that are readily > available, which would simplify the project. Any "gotcha's" in this > scenario ? The obvious one is the protocol. Or rather protocols, since there are so many. PS/2, PC serial, SGI serial, etc are all different. However, if you're talking about basic quadrature mice that simply output X, X', Y, and Y' pulses, your idea should work. Add a PIC and some software and you could handle the other types, too. -- Pete Peter Turnbull Network Manager Dept. of Computer Science University of York

25 years, 4 months

Solbourne Sun workalike for free

by MTPro＠aol.com

Hello, here is someone looking to get rid of some stuff! Please respond directly to him. Best, David David Greelish Publisher Classic Computing Press www.classiccomputing.com From: scott(a)aptest.com (D. Scott Secor) I was curious whether you might know of a deserving organization that would want a Solbourne model 6/500 (Sun workalike) dual processor server in roll-around cabinet. Processor boards were checked by Grumman two years ago after system was taken out of service. Original cost in early 1990's was over $60K. Regards, Scott Secor secor(a)mn.rr.com y2k(a)uswest.net

25 years, 4 months

"Real" emulation...

by jpl15＠panix.com

While mulling over some ideas for software music synthesiser programs [I just bought a copy of Reaktor - a software synth/sampler construction kit of amazing complexity] I started wondering just how close to 'real' an emulator ought to be. For example, the MiniMoog emulator has a replica of the add-on A-400 oscillator, used to tune your Moog back up as it drifted off pitch, which they all did more or less constantly. The documentation mentions retaining this feature even though the emulation no longer drifts. But: why not? Shouldn't it drift, actually? So I ask from a "purist's purist" view... shouldn't an emulator contain "failure modes" common to the machine emulated? And if it "breaks", then the poor "operator" is afforded the opportunity to diagnose and then (hopefully) "fix" the problem. My experience with the various PDP-11 systems I owned was like this. I spent a *lot* of time doctoring the hardware. The same thought could be applied to a software Moog Modular synthesiser system. If a module 'breaks', you have to open up the code, find the 'defective' module and 'fix' it. One could continue this thought right down to having models of components, a la SPICE and the other design modelling software. Each component or module would then have a live/die algorithm associated with it. Imagine how thrilled Tony Duell would be with a PERQ emulator that exhibited random 'hardware' failure modes (based on maintenance histories) that then needed to be repaired at the 'component' level. Running, of couse, on a palmtop. Hopefully one could as well disable the "real-world hardware failure" mode, in the case of wanting to just do something trivial, like program the thing. Silly questions, but also maybe valid.... Cheerz John

25 years, 4 months

Apple external SCSI drives

by dhquebbeman＠theestopinalgroup.com

> > > The first alternative works very well indeed. The second won't, though. > > > Macs use hard drives with a particular Apple firmware, without which HD SC > > > Utility won't recognise the drive. Bloody stupid. Another Apple > > > peculiarity would be its lack of support for remote start in > > > SCSI, so the hard drives will need to jumpered for automatic start on > > > power, but this won't affect other systems. > > > > Non-Apple drives work quite well with Macs; however, while your > > observation about the use of Apple's HD SC Utility is correct, > > all non-Apple SCSI drives sold *FOR* the Mac come with their > > own SCSI setup utility. > > Granted, I forgot to mention that there are other SCSI setup utilities, > but why in the world would one need to buy a drive /for/ a particular > brand of computer? A hard drive is a hard drive is a hard drive. Because the computer manufacturer's engineers, in their infinite wisdom, decided their computer needed feature <X>... For Pr1me minis, hard drives have to be able to support a sector size of 2080 bytes, instead of or in addition to the usual 512-byte sector support. With Apple, their *first* hard drive (a non-SCSI unit) had things called disk tags that required drives that support a sector size of 576 bytes (from memory, probably wrong). I'm not defending the practice; while I assumed your remark was rhetorical, not everyone in the audience may be as well-informed as we are. > > For a SCSI drive *NOT* sold _for_ a Mac, you'd need a third-party > > toolkit like FWB' Hard Disk Tools (or whatever it's called). I've > > used it to add IBM and DEC SCSI drives to a Mac. > > I've got an Apple-edition IBM drive in a IIcx here. =) I've got one of those, too, and it looks *just* like the non-Apple edition. Scary... -dq

25 years, 4 months

Laser 128 expansion port

by SUPRDAVE＠aol.com

In a message dated 1/10/01 2:12:24 AM Eastern Standard Time, THETechnoid(a)home.com writes: << A recent message mentioned that the Laser 128 has an expansion port which can use Apple II cards. Is this accurate? If so, I think I'll dig my laser out and dog the hell out of it. I had no idea. BTW, anyone got a scsi card for Apple II they don't want or need? Regards, >> You are supposed to run the laser expansion box off that slot connector, but one time long ago i desperately needed another drive on my laser so i plugged in my disk ][ controller and it worked! its not very pretty hanging off the side, but its worth a try. anyway, i'm keeping my scsi card...

25 years, 4 months

Nuke Redmond!

by kyrrin＠bluefeathertech.com

At 00:35 10-01-2001 -0500, THETechnoid wrote: <long, pointless rant snipped> And this is related to classic computers, how? Despite the fact that I have no great love for M$ myself, I'm going to limit my comments to this. If you want to expend time and effort venting against Billy-boy and the Redmondians, please put up a web page or something. I have far more important things I choose to concentrate on -- AND read about on this group. *PLONK!* -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Bruce Lane, Owner and head honcho, Blue Feather Technologies http://www.bluefeathertech.com // E-mail: kyrrin(a)bluefeathertech.com Amateur Radio: WD6EOS since Dec. '77 (Extra class as of June-2K) "I'll get a life when someone demonstrates to me that it would be superior to what I have now..." (Gym Z. Quirk, aka Taki Kogoma).

25 years, 4 months

VCF East Survey

by vcf＠siconic.com

In planning for a VCF East Coast, I wanted to take a poll from folks as to where the ideal location would be. I am currently thinking that somewhere in the New England area would work the best, but what do I know, since I've never been there (besides passing through the airports). In deciding on a locale, I'd like to keep these criteria in mind: 1) Availability of an affordable location suitable for the Festival 2) Geographical proximity to the most number of potential attendees 3) Proximity to major airports 4) Availability of decent accomodations 5) Weather 6) Historical relevance (i.e. near Route 128, as a parallel to doing the main Festival in the Silicon Valley) So if those who are entertaining the notion of going to a VCF East could mosey on over to the following URL and fill in the survey I'd be most appreciative. http://www.vintage.org/survey.html This will help me decide on a place to host the first VCF East. As far as timing, it will have to fall somewhere in between VCF Europa (April 28-29, 2001) and VCF 5.0 (Fall 2001). Basically, late Spring, early Fall. Thanks! Sellam Ismail Vintage Computer Festival ------------------------------------------------------------------------------ International Man of Intrigue and Danger http://www.vintage.org

25 years, 4 months

Want to scrap/salvage: hi-tech equipment (populated circuit boards & equipment racks, chassies, etc.)

by etanaka＠mlcp.com

Hello. We are looking to salvage a quantity of populated circuit boards, 19" equipment racks, smaller chassies and other various hi-tech equipment over the next couple of weeks and need a salvage company that can work with us -- Southern California. How do we proceed? Please advise. Thank you. --------------------------------------------------------------------- Eric A. Tanaka MLCP - Multi-Link Communications Products WAN/ LAN Equipment: ADC-Kentrox Adtran Ascend Bay Networks Cascade Cisco / StrataCom Larscom Micom Motorola N.E.T. Newbridge Nortel Networks Paradyne Racal 3Com / US Robotics Timeplex Verilink & others tel............800 TO MULTI (800 866 8584), ext. 14 tel............+1 310 320 1451 fax...........+1 310 320 1551 email...... etanaka(a)mlcp.com URL........ http://www.mlcp.com ---------------------------------------------------------------------

25 years, 4 months

Functional Archive?

by djg＠drs-esg.com

Is there currently any functional archive of this list? www.classiccmp.org doesn't seem to be updating any more. Thanks, David Gesswein http://www.pdp8.net/ -- Old computers with blinkenlights

25 years, 4 months

New finds

by rigdonj＠intellistar.net

In the last couple of days I hit a used book store, scrap yard and Skycraft (THE mother of all surplus stores!) and came away with a good pile of stuff. Motorola Exor-bus CPU card with 6809 CPU, a pile of 7 more Exor-bus cards (Mike, where are you?) and a Rockwell R6500 AIM computer built into some kind of an incomplete machine. It has a riser card on the expansion connector and a second circuit card plugged into the riser. The only name I can find on it is "Aeronca Electronics Inc - 1984". The card has three DataSentry NiCad batteries on it along with two R6522P ICs and two HM 6116 Static Rams. Anyone know what this might have been? Other hardware includes an OMTI bridge board. It's a model 5400. Does anyone know what it is? I haven't had time to research it. Other goodies include "Interfacing to S-100/IEEE696 Microcomputers" by Sol Libes and Mark Garetz, "Starting Forth", "Thinking Forth" and "Discover Forth". Also "Principles of Data Processing with BASIC" from 1970. It's not too exciting except for a section on the IBM 29 card punch in the appendix. Other bookies include "Assembly language for the IBM-PC" by Kip Irvine and "Fundamentals of Logic Design" by Roth. They both look like good books. Joe

25 years, 4 months

VGA card - 8 bit?

by donm＠cts.com

I guess that this is a rather naive question, but is there any such thing as an 8-bit VGA card? If not, is the 16-bits necessary or is it just because it came about after 16-bit ISA came along with the AT class computers? - don

25 years, 4 months

New finds

by mcguire＠neurotica.com

On January 9, Joe wrote: > Other goodies include "Interfacing to S-100/IEEE696 Microcomputers" by > Sol Libes and Mark Garetz, "Starting Forth", "Thinking Forth" and "Discover Wow, Sol Libes! Haven't seen THAT name in a while. I think I had that book at one point. Neat score! -Dave McGuire

25 years, 4 months

Found Apple II SCSI card

by SUPRDAVE＠aol.com

In a message dated 1/9/01 5:52:32 PM Eastern Standard Time, foo(a)siconic.com writes: << Yes! I finally found an Apple II SCSI card. It was inside a //gs I picked up at a thrift store (complete with the AppleColor RGB monitor for $20). Funny how you don't pay attention to certain messages until you get one of what's being discussed yourself :) But my questions is, I can use this in an Apple //e as well, right? >> yes, you can even use it in a ][+ although you have to have 64k so as to run prodos. It would probably even work in a laser128's expansion slot too.

25 years, 4 months

Found Apple II SCSI card

by foo＠siconic.com

Yes! I finally found an Apple II SCSI card. It was inside a //gs I picked up at a thrift store (complete with the AppleColor RGB monitor for $20). Funny how you don't pay attention to certain messages until you get one of what's being discussed yourself :) But my questions is, I can use this in an Apple //e as well, right? I also picked up a hard drive and some external floppies for the Mac that was there, but I'm wondering if maybe these were used on the GS? The one floppy is an Epson which I know is for the Mac, and the hard drive is a Data Frame DF20. I wonder if I can use this with the GS? Sellam Ismail Vintage Computer Festival ------------------------------------------------------------------------------ International Man of Intrigue and Danger http://www.vintage.org

25 years, 4 months

OT-ish : Centronics printer port timing

by pete＠dunnington.u-net.com

On Jan 9, 18:35, Tony Duell wrote: > I have a reasonable set of IBM Techrefs, and the timing for the 'IBM > Graphics Printer' (a rebadged Epson MX80 or something like that) is much > the same. In fact that's what I used as the 'standard' to design my > interface. Of course what I'll discover too late is that the Epson timing > (or that of other common printers like the Deskjet family) didn't > actually have to be anything like that and that the authors of various > OSes did something totally different that worked with common printers... FWIW, the two assembly-language routines I can think of that used 7-bit ASCII (one on a Z80 and one on a 6502) both did it by waiting for BUSY to go false, then wrote (char AND 7FH) to the port, wrote (char OR 80H), wrote (char AND 7FH) again, and exited. The eighth data bit was inverted and used as the strobe. -- Pete Peter Turnbull Network Manager Dept. of Computer Science University of York

25 years, 4 months

OT: Lightning vs Lightning Bug (Was: RE: Digital Ethernet Local N etwork Interconnect (DELNI)

by dhquebbeman＠theestopinalgroup.com

> I recently came into possession of about half a dozen of the Digital > Ethernet Local Network Interconnect (DELNI). This is about 4 more than I > need. I am willing to trade them singularly for something anyone has that > can peek my interest. I am particularly interested in items that is ^^^^ > associated DEC, HP and IBM workstation The sought-after word there was "pique". ;-)

25 years, 4 months

OT-ish : Centronics printer port timing

by ard＠p850ug1.demon.co.uk

A non-text attachment was scrubbed... Name: not available Type: text Size: 906 bytes Desc: not available Url : http://www.classiccmp.org/pipermail/cctalk/attachments/20010108/8c77a505/at…

25 years, 4 months

Sharp MZ-80K Available in UK

by pete＠dunnington.u-net.com

On Jan 9, 15:22, Kevan Heydon wrote: > > The guy in the mail below has a Sharp MZ-80K he wants to get rid > of. Please reply to him directly, I don't think he is going to be willing > to post so I think you will have to collect from Bristol. > ---------- Forwarded message ---------- > I don't really want it, but rather than throw it in a skip, I am trying to > find a good home to give it to. Do you want it (I note you already have > one) or do you know anyone who does? I have one too -- but I think I'm missing the BASIC tape. Could you do me a copy sometime? -- Pete Peter Turnbull Network Manager Dept. of Computer Science University of York

25 years, 4 months

cray el (uk) needs rescue

by pete＠dunnington.u-net.com

On Jan 9, 10:10, Stuart wrote: > Hi all, > I've been offered a Cray EL in the UK, that frankly, is too big for me to > handle. A good home is needed to offer removal and relocation, or else it > will be scrapped. The machine is non-operational. > Interetested parties should e-mail me. Stu, you could ask Jim Austin (whom I think you know (of)) -- I'm sure he has space since I just moved some of my stuff out of his storage. He already has a Y-MP and a few bigger things. -- Pete Peter Turnbull Network Manager Dept. of Computer Science University of York

25 years, 4 months

OT-ish : Centronics printer port timing

by pete＠dunnington.u-net.com

On Jan 8, 22:33, Tony Duell wrote: > That's what most of the printer manuals I've seen say as well -- get the > data stable for 0.5uS, bring stb/ low for 0.5us-1us (I saw the correction > you posted) and then keep the data stable for 0.5us after stb/ has risen > again. > Oh well... I'll try the falling edge (which is what the majority of > machines use) and moan about machines that violate the (non-existant?) > standard. The only genuine Centronics manuals I have are for the Centronics 737/739 printers, but for what it's worth, the technical section says the data must be valid for 1us before the leading edge of the negative-going strobe pulse, the pulse should last a minimum of 1us, and the data must remain stable for 1us after the trailing (rising) edge. Of course, this isn't necessarily a standard, just what one Centronics printer wants. In this particular series, the BUSY signal goes active (high) on the trailing edge of ~STROBE (within 50ns) and remains active until the leading edge of ~ACKNLG (within 50ns); ~ACKNLG goes low (active) 300-470us after the trailing edge of ~STROBE (or once the line is printed if the character received is a CR), and lasts for 5us. The only other handshake is ~DEMAND, which is the inverse of BUSY. I used to have some Epson manuals, and I'm sure they use the leading (negative-going) edge of ~STROBE as well. -- Pete Peter Turnbull Network Manager Dept. of Computer Science University of York

25 years, 4 months

Not a BA212, what is it? VAX Question

by cmcmanis＠mcmanis.com

Well, this is truly interesting. I cleaned up and checked out the VAX 4000/200 I got in what I thought was the BA212 cabinet. But it isn't. The tag on the side calls it a BA400 series (and the power supply certainly bears that out) but it is like the BA212 in that the card cage is _behind_ the drive bays. The drives are your standard BA440 type removable (who ever invented that guide/track system does NOT get any bonus points) and the front cover doesn't have a door, only a cover to prevent the drives from being removed when it is in place. Does anyone know what chassis type this is? The system was built in 1991 (see, its on topic now :-) but I've not got a later version of the MicroVAX Technical Handbook which might describe it (the version I have describes the BA440 with the VAX 4000/300) --Chuck

25 years, 4 months

← Newer
1
...
10
11
12
13
14
15
16
17
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 January 2001