test-drb

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101090 discussions

by cclist＠sydex.com

Date: Sat, 26 Jan 2008 17:21:56 -0500 From: Sean Conner <spc at conman.org> > I came across this bit of code from http://www.hackersdelight.org/ to > divide by 10: I think that goes back to my original suggestion of effectively multiplying by a scaled reciprocal approximation of 0.1. The 6 in the last computation statement appears to be some sort of rounding factor. The problem as stated however, was to calculate x/10 and mod(x,10) (i.e. the remainder). Dwight seems to have figured this one out at least for the range of 0..799. If you/re a PIC programmer, there's a very cool web site that features a code generator for various problems: http://www.piclist.com/techref/piclist/codegen/index.htm But double-check the code that's generated; I've occasionally found some errors. Cheers, Chuck

18 years, 2 months

SGI Octane 2 on Craigslist

by cclist＠sydex.com

Eugene, OR area: http://eugene.craigslist.org/sys/551185465.html Cheers, Chuck

18 years, 2 months

non-existence of printer collectors...proven wrong

by Arno_1983＠gmx.de

Cameron Kaiser <spectre at floodgap.com> wrote: > > But nobody collects printers, not even vintage ones. > > Because they're big and heavy and power-hungry, and they're always > running out of supplies when you try to do anything useful. So let's say they're just not for the faint of heart ;) I for one have to plead guilty of printer packratting, having piled up an assortment of impact matrix and laser printers mainly (I'm less fond of inkjets because they always clog up if you don't use them regularly). So let's see what's around here: Pin impact: Commodore MPS-802 (first printer in household) NEC Pinwriter P2200 (printer of our first PC) NEC Pinwriter P6+ NEC Pinwriter CP7 (four-zone ribbon color printer) Epson LQ100 (neat little dot matrix unit, even used sometimes) Epson LQ-570+ Epson LX-400 Epson TM-267IIB (serial receipt printer) Oki Microline 591 Star J120 Inkjet: Canon BJ-10sx Canon BJ-20 Canon BJC-85 Canon BJC4100 HP DeskJet 660C (first color printer of my dad) HP DeskJet 1200C HP DeskJet 1600C(M), 3x (professional inkjets with drier lamp) Epson Stylus COLOR (nonstandard appearance for an inkjet) Lexmark Color Jetprinter 1000 (modern exterior) Lexmark X1160 (USB Scanner/printer combi) Laser: Citizen Overture 106 Apple LaserWriter II NTX Apple LaserWriter Pro 630 Epson EPL-5000 Epson EPL-7100 HP LaserJet Series II Siemens PT10 (rebadged HP LaserJet II) HP LaserJet IIISi HP LaserJet 4L (unusually flat laser) HP LaserJet 4 brother HL-1260e (the only one regularly in use; same engine as LJ4) HP LaserJet 4Si (honkin' big cube) HP LaserJet 5L HP LaserJet 6L HP LaserJet 2100M Kyocera F-1200 Thermal transfer Okidata unit with c/y/m/k transfer strips chained in a ribbon cassette two Mitsubishi still image printers (CP100E, CP250E?) with TTL, VGA, RGB and composite video inputs in addition to parallel ...and probably some more buried somewhere that I don't yet have in my inventory. People keep telling me I have to cut down on such stuff (as well as commodity PCs) but whenever I start to think about which to throw out, I get to think about each one's unique features and what I would say if somebody asked me tomorrow if I had a printer for that-and-that specific location and application. One of my yet unfulfilled dreams is a daisywheel printing terminal (Diablo 1620 or similar). Enough of a confession? So long, Arno -- Arno Kletzander Student Assistant // Studentische Hilfskraft Informatik Sammlung Erlangen www.iser.uni-erlangen.de Der GMX SmartSurfer hilft bis zu 70% Ihrer Onlinekosten zu sparen! Ideal f?r Modem und ISDN: http://www.gmx.net/de/go/smartsurfer

18 years, 2 months

the non-existence of printer collectors

by djg＠pdp8.net

> 1) "interesting" printers are large and power hungry and frankly hard > to find in isolation. When they are around, they are usually part of > a large mainframe/minicomputer package and you can't get *just* the > printer. > Those old line printers had such a nice impressive sound. At least looking back and when you will be doing short printouts on a classic computer. When you had to listen to it all day not so good. Way back in college they had a 9-1/2 DEC line printer drum/band on an old PDP-11. That would be about the right size to make a nice addition to my collection. Never have seen one like that since then and don't know what the model was. Whenever I find a DECwriter II (or unlikely I) within a reasonable drive I will add one of them to my collection. Do have a DEC dasywheel, a couple of dot matrix PC printers, and an ASR-33

18 years, 2 months

2716 with 100 nS access time ?

by cclist＠sydex.com

> Date: Fri, 25 Jan 2008 21:11:26 +0100 > From: Jos Dreesen / Marian Capel <jos.mar at bluewin.ch> > I need a programmable device, with the standard 24 pin layout, with 100nS > acces time. 2716's are 350ns to 450ns, 2816's are 150nS match. What other > options do I have ? How about a NV SRAM, such as the DS1220? 100 nsec, 24-pin JEDEC pinout. Or an ST M48Z12, same-oh pinout and capacity? Are you trying to replace something like an 82S191? Cheers, Chuck

18 years, 2 months

Zenith Data Systems Terminals at U of Washington auction 2/2/08

by bnansel＠bigpond.net.au

> Spotted in the University of Washington's Auction Catalog are 8 Heath > Zenith Terminals. I don't think they are Z100 all in ones as I don't > see any drives. Lot 40. Wow, that takes me back. Hacking away on Pascal programs on H-19 terminals in the H-19 editor at two-thirty in the morning in the ACC...the vending machine that dispensed rhino piss they claimed was tea. Oh, those were the days. H-19 was the first screen editor I ever used, though I never did get used to the "colour" command system they introduced in later years. Bah, the old system worked fine, why did they hafta go and change it? -Bobby

18 years, 2 months

I propose to make the journey in 1973...

by pichotjm＠free.fr

I had the opportunity to conduct a series of photographs when I participated in the fair 'Le Bourget' in 1973. You will see about 200 original pictures of displays, keyboards, computer terminals, cameras, radar displays, screen shots of weather, tactical, electric power plant, road traffic, and 8 american or soviet satellites. The visit is here: http://pichotjm.free.fr/Techno73/Techno73US.html The root address http://pichotjm.free.fr will lead you in early computers... (1954 to 1975) Enjoy! JMP

18 years, 2 months

the non-existence of printer collectors

by billdeg＠degnanco.com

> >Subject: Re: the non-existence of printer collectors was Re: A sign of > the times > >I actually have an interest in printers, but there are the following >problems: > ><snip> >2) Printers were commoditized quite some time ago. Remember the Epson >FX-80? (And later the RX-80.) A printer was one of the few >peripherals that *everyone* who had an Apple ][/IBM PC (or clone) >needed. (Paperless office, my ass!) As a result printers were one of >the few things that could be commoditized across all brands of >computers from micros to mainframes -- although it would probably look >silly to have an Epson FX-80 hooked up to a mainframe! I brought this topic up as a thread on vintage-computer.com/vcforums. I keep one printer per system type in operational condition, and use them for comprehensive testing of systems. Same goes for modems. I think that the Diablo printer is worthy of collecting (I have an Commdore-branded OEM model CBM 8300P, which is quite rare I believe). A nice IBM Proprinter is worth holding onto. Boxed printers are easy to store, I prefer printers in their original boxes, otherwise I am less likely to keep them. Bill D

18 years, 2 months

A sign of the times. (Laserjet 4000s here)

by technobug＠comcast.net

On Sat, 26 Jan 2008 10:19:19 +0000, Stroller <classiccmp.org at stellar.eclipse.co.uk> wrote: > *sigh* > > I have a similar conundrum here. > [...] > The HP engineers intended for this part to be easily > replaceable, and you can easily pick up a roller set on eBay. > Unfortunately the price comes to about ?12 per tray - or perhaps ?25 > shipped for rubbers for both lower trays plus the manual feed pickup, > too - and these printers have a resale value of only ?35. > > [...] > Stroller. > > You might want to check out <http://www.partsmart-corp.com>. The pickup roller is $1.00. They have replacement parts for all sorts of laserwriters and have presence on many sides of the pond. Good folks - just a very satisfied customer... CRC

18 years, 2 months

A sign of the times. (Laserjet 4000s here)

by compoobah＠valleyimplants.com

On Jan 26, 2008, at 5:22 AM, Stroller wrote: > I think it's tragic to be throwing out such decent & solidly- > constructed printers in favour of cheap plastic rubbish - in the > event a repair is necessary the kind of printers we can get for less > money will complain about disassembly with the "pling" of flying > broken-plastic sproggets - but it makes little economic sense to do > otherwise. I've been meaning the last week to try & find a source of > Laserjet rollers where I can purchase 10 or 20 at more sensible > rates, but I'm not overflowing with optimism. I tend to like the better printers even if you do have to put some $ into upkeep. I made that decision after cursing out a cheap printer that would have "issues" often.

18 years, 2 months

the non-existence of printer collectors was Re: A sign of the times

by ajp166＠bellatlantic.net

> >Subject: Re: the non-existence of printer collectors was Re: A sign of the times > From: Jim Leonard <trixter at oldskool.org> > Date: Fri, 25 Jan 2008 22:41:35 -0600 > To: General at mail.mobygames.com, "Discussion at mail.mobygames.com":On-Topic and > Off-Topic Posts <cctalk at classiccmp.org> > >Cameron Kaiser wrote: >> I do keep an Apple LaserWriter around, but mostly because anything can >> talk to it, and HP LaserJet supplies are easy to find. > >I second the part about LaserWriter. The only printers I accept in the >house are Postscript because anything can talk to them. Me I have a HP 4L, Epson LQ5000 for the parallel interface printers that speak basic ASCII as well as other protocals. I may have a MX80 as well. For the serial interface printing camp a pair of LA100RO. Not all of my systems speak postscript, they all speak ASCII. Allison

18 years, 2 months

Proper spacebar repair on XT 83-key?

by trixter＠oldskool.org

The spacebar died on the last working 83-key XT keyboard I had (I have three, and ALL have non-functioning spacebars), so I decided to finally choose one to take apart and try to clean with compressed air, etc. All of the keys came off okay; I put the plastic parts *only* in the dishwasher (mild soap, warm water, nothing harsh) and cleaned the rest by hand by shooting compressed air into every buckling spring hole. But when it came time to put the spacebar back on, I noticed that both ends of the spacebar have two little "hooks" that are supposed to hook onto two little prongs of metal underneath the top of the assembly. These provide necessary support, as the spacebar will bend if pressed at the edges instead of going straight down. Only problem is, I can't seem to get these re-hooked! The only way I can see getting the spacebar back on, barring some trick I don't know about, is to take the metal back off the assembly and try to re-hook it from underneath. But I'm terrified that, if I try to take the back off, 83 buckling spring assemblies are going to fly every which way from the unit and I'll be left with a worthless hunk of junk. It also doesn't look like it was meant to be taken off anyway, as one of the metal tabs on mine seems intentionally bend downward to prevent this. For those who need pictures, I've taken some snapshots of the problem and put them here: ftp://ftp.oldskool.org/pub/misc/keyb/ Any advice is appreciated -- either that, or a source for more 83-key XT keyboards... -- Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/ Help our electronic games project: http://www.mobygames.com/ Or check out some trippy MindCandy at http://www.mindcandydvd.com/ A child borne of the home computer wars: http://trixter.wordpress.com/

18 years, 2 months

DOSBox...

by cclist＠sydex.com

> Date: Fri, 25 Jan 2008 16:40:09 -0600 > From: Jim Leonard <trixter at oldskool.org> > Yes. In fact, myself and a few others have done significant work trying > to get CGA properly emulated (composite CGA emulation is pretty damn close > to the original; some tweaked modes work as well). It can even boot > bootable diskette images (as long as copy protection is absent). ...and that's just the problem here. The program diskette is copy- protected. What what, I'm not sure. Cheers, Chuck

18 years, 2 months

Subject: RE: Subject: Re: div by 10 on Z80

by cclist＠sydex.com

> Date: Tue, 22 Jan 2008 19:33:15 -0800 > From: dwight elvey <dkelvey at hotmail.com> > Here goes with using your idea to double use the a register. Except > If I start it with 2, I can use the carry instead of the sign bit. What > fun! > > Div10: > ld a,#2 > ld de,#-640d > divloop: > add hl,de > jr c, div1 > sbc hl,de > div1: > rl a > jr nc,divloop > add hl,hl > ret Ah, but you forgot the add hl,hl to shift the dividend after each iteration. Put it at the top of the loop so it doesn't interfere with the operation of the "rl a/jr nc" pair and scale your divisor by an additional power of 2 and you should have it. By now, we've probably bored the hardware guys to tears and DEC people are tearing out their hair, so we should probably drop the subject. My apologies, but I've always found bit-twiddling fun. It seems that every platform has some peculiar characteristic that can be exploited to good advantage. Cheers, Chuck

18 years, 2 months

Ribbons for your teletype model 43 on ebay

by legalize＠xmission.com

I purchased two from the guy. They are NOS and the ribbon hasn't dried out. He apparently has a bunch of them. He's selling them for $15 each, but he will combine shipping if you buy more than one. I tried to arrange a discount for buying 5, but he was firm in his pricing. So I bought 2. I figure that if I use them both up, I can try my hand at re-inking the ribbon. At $75 for 5 ribbons, that was more than I paid for the terminal itself :-). -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://www.xmission.com/~legalize/book/download/index.html> Legalize Adulthood! <http://blogs.xmission.com/legalize/>

18 years, 2 months

2716 with 100 nS access time ?

by jos.mar＠bluewin.ch

I need a programmable device, with the standard 24 pin layout, with 100nS acces time. 2716's are 350ns to 450ns, 2816's are 150nS match. What other options do I have ? ( Target : replace some bipolar microcode proms So I can experiment a bit) Jos

18 years, 2 months

Dead IBM PC 5150 motherboard - help troubleshooting

by richard.beaudry＠gmail.com

Hello all, I have an IBM PC, 5150, 16-64KB motherboard, that appears to be dead. Power on produces no display or disk activity (even after a while), and no beeps >from the speaker (I tried a couple of speakers, so I don't think it is a speaker issue. >From what docs I found on the internet, the switches are set up properly for the machine's configuration... I am pretty sure the motherboard is getting power. I checked at a RAM socket, and all voltages were there, and well within specifications. The problem is, I'm not sure where to go from here. I have NO schematics, and haven't ever troubleshot a 5150 before. I DO have a good meter, and a scope (and I know how to use it!) What would be the first things to check? Thanks for any help!!! Rich B.

18 years, 2 months

2716 with 100 nS access time ?

by ajp166＠bellatlantic.net

> >Subject: 2716 with 100 nS access time ? > From: Jos Dreesen / Marian Capel <jos.mar at bluewin.ch> > Date: Fri, 25 Jan 2008 21:11:26 +0100 > To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> > >I need a programmable device, with the standard 24 pin layout, with 100nS acces time. >2716's are 350ns to 450ns, 2816's are 150nS match. >What other options do I have ? > >( Target : replace some bipolar microcode proms So I can experiment a bit) > > Jos The only way you can get to under 100ns is using larger EEproms or Eproms as their smaller feature size made them faster. You can get 27256s under 100ns (might be cmos but no matter) and larger parts go down to under 50ns. Ofcourse that means a chip adaptor but thats no big deal. Allison

18 years, 2 months

UK assistance requested

by jfoust＠threedee.com

At 01:16 PM 1/25/2008, from at fu3.org wrote: >2008/1/25, Chuck Guzis <cclist at sydex.com>: >> trying to get an old PC program (on 3.5" media) going on his >> modern PC system. He's run into one of the copy-protection schemes >> that worked fine under MS-DOS but not under 2K or XP. > >DOSBox sends its regards. Yes, it's great for reviving old programs under contemporary Windows. http://en.wikipedia.org/wiki/DOSBox , at http://www.dosbox.com/. - John

18 years, 2 months

Z80 Divide by 10

by cclist＠sydex.com

From: dwight elvey: Well, you've got me confused. HL = dividend (Dnd) > ld d,h > ld e,l ; DE=Dnd > add hl,hl ; HL=Dnd*2 > add hl,hl ; HL=Dnd*4 > add hl,de ; HL=Dnd*5 > add hl,hl ; HL=Dnd*10 > ld b,h > ld c,l ; BC=Dnd*10 > add hl,hl ; HL=Dnd*20 > add hl,hl ; HL=Dnd*40 > add hl,bc ; HL=Dnd*50 > add hl,de ; HL=Dnd*51 ; At this point, HL=0-41000 > ld a,h ; A=HIGH(Dnd*51) > rra ; A=HIGH(Dnd*51)2 > ld l,a ; L=HIGH(Dnd*51)/2 ; At this point, you've lost me. But a non TLU fall-through 10-bit divide with only one conditional branch at the end would be worth a paper in CALGO, surely. Cheers, Chuck

18 years, 2 months

Ohio Scientific

by djg＠pdp8.net

I'm working on getting my Ohio Scientific Challenger II running. The system is a 505 CPU (first rev that doesn't match schematics online), 535 memory 48k (no schematics online I have found), 540B video card with color and dual 8" floppy. This machine was modified with a switch so I can use either the video board or a serial terminal. Its pretty close to the system I first used in high school. I think I have the computer working but would like to run a memory test. Does anyone know of one available that I could load in through the monitor? Or do I need to see how much 6502 I can remember from 25 years ago? The video card generates the first line right after end of vertical blank so all my monitors cut off most of the first line. Is this normal? Next is moving on to the the 8" floppies. After I get them working I want to dump all the disks I have. I found at osiweb a program to dump floppies but it was for 5 1/4". Does anybody know of one that will dump the 8"? Perferably in a format that an emulator can use so I can verify the dumped disks are good.

18 years, 2 months

Link: IBM's anti-MacBook Air goes up for sale on eBay

by lproven＠gmail.com

http://www.reghardware.co.uk/2008/01/25/ibm_5155_up_for_sale/ Quote: [ Forgotten Tech Want to own a piece of portable computing history? Actually, we use the word 'portable' advisedly - we're talking an IBM 5155 here, a 30lb (13.6kg) monster that, as the eBayer offering it up to the highest bidder admits, "is not a MacBook Air". ] Amusing, even affectionate, story and indeed auction description, too. -- Liam Proven ? Profile: http://www.linkedin.com/in/liamproven Email: lproven at cix.co.uk ? GMail/GoogleTalk/Orkut: lproven at gmail.com Tel: +44 20-8685-0498 ? Cell: +44 7939-087884 ? Fax: + 44 870-9151419 AOL/AIM/iChat: liamproven at aol.com ? MSN/Messenger: lproven at hotmail.com Yahoo: liamproven at yahoo.co.uk ? Skype: liamproven ? ICQ: 73187508

18 years, 2 months

Subject: Re: div by 10 on Z80 was RE: Reading Polymorphic

by cclist＠sydex.com

> Date: Sun, 20 Jan 2008 20:57:27 -0800 > From: Brent Hilpert <hilpert at cs.ubc.ca> > Subject: Re: div by 10 on Z80 was RE: Reading Polymorphic --- > (I expect you may have noticed already..) the subroutine (div10s) is > only called once now, you could inline it to save another 4 bytes. You can do a bit better with that and by using the carryout to form the quotient bits: div10: xor a ld de,0fd80h ; largest power of 2 times 10 less then 800d ld b,07 ; only seven loops needed to finish divide 80 divloop: add hl,de ; trial subtract jr c,div10s1 ; carry means trial passed sbc hl,de ; undo previous add, carry is clear div10s1: rl a add hl,hl ; shift number to reuse same constant, 640 decimal djnz divloop add hl,hl ; push full remainder in HL ret Again, I haven't tried it out, but it should work. Cheers, Chuck

18 years, 2 months

div by 10 on Z80

by cclist＠sydex.com

> Date: Wed, 23 Jan 2008 18:48:27 -0700 > From: woodelf <bfranchuk at jetnet.ab.ca> > Well it does make for Software Updates to come out a **Tad** Slower > than most systems. Look at the ADVENTURE update, almost 20 years later. > :) I assume that was an intentional pun. Very clever. Cheers, Chuck

18 years, 2 months

cctalk Digest, Vol 53, Issue 44

by compoobah＠valleyimplants.com

On Jan 22, 2008, at 11:52 PM, cctalk-request at classiccmp.org wrote: >> 12) Bend over the locking tap, refit the case. > > It's not the same without the Terry Davey cutaway drawings and > "Refitting is > the reverse of removal" ;-) The one I like is the stock "this was changed in the XXXX model year" Oh, very helpful. About as helpful as a MS-DOS 6 bundled "user's guide"

18 years, 2 months

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