On 11/06/2012 12:34 PM, Ethan Dicks wrote: That should have been Z280 MMU not Z180. Between the two there is night and day for MMU ops in structure and programming. The Z280 does a scatter gather map like PDP11 MMU and the Z180 does a start page end page mapping. CP/M is a file system and the abstracted IO is in the BIOS, why not add to the bios a taskmanager that has an interrupt driven tasklist to run multiple CP/M spaces sharing the bios and BDOS(filesystem). Nothing says you cannot. Therein lies the problem. CP/M80 was single user. CP/M+ or MPM added the multitask layer with what we call legacy compatibility (single 64K page mapping). IF DOS/8088 did not enter when it did then where we might have gone is still open. CP/M is still useful and z180s are availeble to beyond 20mhz imagine a 20 or 33mhz Kaypro.. Allison

On 11/06/2012 05:11 PM, Fred Cisin wrote: I've used the JLASER card. It was really quite nice. QMS made a similar device, an ISA board which turned LaserJets into PostScript printers, using the direct video interface slot. I don't see why not. I wouldn't want to try to write a PostScript interpreter on an 8-bitter, though. ;) -Dave -- Dave McGuire, AK4HZ New Kensington, PA

On 11/06/2012 06:15 PM, Fred Cisin wrote: Neat! I didn't know there were others. Postscript really is a wonderful thing. :-) -Dave -- Dave McGuire, AK4HZ New Kensington, PA

On 06/11/12 7:16 PM, Fred Cisin wrote: It's stack based. Beyond that there's not that much similarity. The data types and various other features were relatively modern for the time. Definitely deserved its success - an elegant design with a good fit to its application. --Toby

Err, well, you can push thiugs other than integers onto the stack in Postscript. Don't you actua;ly need a printer with the driect 'video' interface for those cards? For CX printers (Lasterjet, etc) that means removing the formatter board and wiring the 34 pin header on the DC controlelr board that conencted to the fomatter to a DC37 conenctor. And if you want, wiring some status LEDs to the appropriate conenctor on the DC controller. The result is a 'CX-VDO' printer. For SX printers (Lasterjet II,. etc), the original way to get this 'video' interfce was to replace the formatter board iwth a buffer board, whioch also includes the necessary DC37 socket. However, IIRC, there wa a3rd party board that fitted the optiaonal interface slot on Canon/HP formatter bords and which provided this interface whille leavign the formatter in position. I have never seen this board, though. The problem with running a CX printer today is tht the toner cartridges are essentialyl unobtainium. I don't use the one on my PERQ for this reason. I suspec tthe origianl Laserjet is heaver. It's got a linear PSU with a massive transfomer for a start. Actually, models with internal formatters have _2_ massive transfromers in the bottom. -tony

No, the HPII cartridges are very readily available, and cheap. http://www.inkjetsuperstore.com/92295A-10?utm_medium=cpc&gclid=CLjwqqLw… eiPPAodIQoAlg&utm_source=google&utm_campaign=hp-toner+cartridge-g&utm_term=9 2295a Cindy Croxton Electronics Plus 1613 Water Street Kerrville, TX 78028 (830)792-3400 phone (830)792-3404 fax AOL IM elcpls -----Original Message----- From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Fred Cisin Sent: Wednesday, November 07, 2012 3:32 PM To: General Discussion: On-Topic and Off-Topic Posts Subject: Re: P112 question - what can you run that uses 1MB of RAM? On Wed, 7 Nov 2012, Tony Duell wrote: Tall Tree used toi sell them this reason. How many times can they be refilled ? quite a bit. the IIP (and IIIP) were lightweight "home" printers for people who didn't want the size, weight, and price of the "real" laserjets. ----- No virus found in this message. Checked by AVG - www.avg.com Version: 2013.0.2742 / Virus Database: 2617/5875 - Release Date: 11/05/12 ----- No virus found in this message. Checked by AVG - www.avg.com Version: 2013.0.2742 / Virus Database: 2617/5875 - Release Date: 11/05/12

I don't know. The CX cartridge will come apart (althouhg IIRC you nweed a tamperproof torx driver). My guess it it wil lstand a few refills -- if you can get hte 'loose' toner. Actually, finding empty cartridges is not that easy now. -tony

I am nto convinced. Many plastixs go brittle with age, asn the plsticiser evapourates. I would guess that for somethign like a toner cartridge the plastic used would not be chosen because it had a long lifetime. Whaere? I have never seen spares for toner cartridges on general sale over here. -tony

On Fri, 9 Nov 2012, Tony Duell wrote: High carbon, high heat plastics are brittle by their nature, but they also tend to age very well. By comparison, PC+ABS blends often age poorly and some blends can become extremely brittle with age. To make matters worse, there seems to be no way to effectively solvent weld PC+ABS blends. On the other hand, most ABS blends /without/ polycarbonate tend to solvent weld very very well with solvents such as dichloromethane (methylene chloride).

These are easy to find in Brazil...Lots of copiers (Canon PC-1 comes to mind) uses that. If I may serve you...

Why? Sure, they are Canon originals, and not expensive, around $30 each. How much do you need? If you're not in a hurry, I may send them thru a friend going to USA.

I believe I even have one sealed here at home. I don't know if it will still work flawlessly, but at least you have a dud for recharging...

What is the physics behind that? AFAIK the toner is elkectrically neutral (it would be veyery odd if it wasn't). In fact IIRC the image formation and trasfer process in the CX (and every other laser printer I've been inside) requires the toner to be attracted ot electrodes of both polarities. -tony

Ires you sure? I have heard, many times, that hte copier cartridges don't work in the printer and vice versa. Of course a copier does 'write for white', printer, at least the CX, does 'write fro black' The polarity of the voltage on some of the corona wires must be reversed as a result, but that wouldn't affect the cartridge. Whetehr the drum is differnet, or the toner, or whether there/s a more stirival change (like the contacts don't line up) I don't know, but I am told you jsut get blank sheets of paper if you use the wrong cartridge. -tony

I wonder whathte physical explanation for that is. -tony

On 11/09/2012 04:37 PM, Dave McGuire wrote: Ok, I'm game. Tell me what toner does a P112 use or is that used to color the 1MB of ram?? HINT: If you arr wandering off at least change the topic. Allison

On 11/9/2012 5:30 PM, Alexandre Souza - Listas wrote: Well if you could access the toner drum directly from the host cpu, I am sure you could emulate a generic mono-spaced printer like a TTY in 16K including the printer fonts. Ben.

On 11/09/2012 07:50 PM, ben wrote: Actually no. To do that you need to be able to process the data rapidly enough to lay down dots as the drum rotates. The key thing for Laser printing (or any page printer) is the bit image need to exist before the paper moves or at least be preprocessed so that the raster image processor can fill a "band buffer" . The Video dot rate for a DEC LN01 (xerox 12PPM engine) was about 7mhz. The early character only version use a 12mhz 80186 with 8089 to keep up, The system IO to the host was handled by the 8089. Oddly the 8PPM LN03 Ricoh based engine was not much slower on the video clock. In the late 80s there were two lasers often those that were band buffer and generally limited to text and limited graphics and a higher priced version that had enough ram to buffer the page so the image could be composed before the paper was even moved. Actually I use my CP/M-80 system to lay down images on a real Laserjet4L. The price is that I need to run the system for a long time to create bit images to transmit. That takes hours even with ram and bit of buffering to hard disk. Even then the printer is doing much of the heavy lifting. The main issue was never ram but CPU cycles to process that data at acceptable rates for graphic images. It is the same issue as doing video graphics on a CRT or LCD. In that case you need enough ram to buffer the image for refresh and enough cpu to create and transfer images to that ram. So to simply move bytes to a 1MB page buffer it would take a Z80 at 4mhz around 8 seconds with no processing other than simple paging. That's too slow. Allison

On 11/9/2012 6:15 PM, allison wrote: That is a mechanical issue, not the idea of charging a drum with a laser. The old, cheaper hardware, faster software problem here. I don't think software has yet to solve the real problem of modern printers, is that text on the screen does NOT match the printed page, but that is off topic. I think history of Time-Sharing computers had a big impact here. You needed BIG fast page laser printer to share between users, so high speed printer was needed. Speed I don't think changed much over the years, but build quality HAS dropped. Custom software, or using a driver for a text processing package? Ben.

On 11/09/2012 08:41 PM, ben wrote: You are not serious. The drum rotates slowly but each line of pixels is the length of the printed area (8") times the 300line per inch of the circumference and at 8PPM the average drum in small printers turned several times to print the whole 11 inchs. It's a raster scan system. Character printers could compose at a rate that was one cell height at a time so they use band buffers that often allowed typically 8 or 16 lines on the drum to be buffered at a time while the next lines were being processed. That scheme was good to a point but there were pathological cases that resulted in page to complex and imaging failures. often overstrikes were the likely culprit. For 8PPM that means moving 7920000 pixels in about 7.5 seconds without much dead time. You cannot stop the drum during the process. The laser does not charge the drum, it's used to discharge it, you can do it with LEDs as well but they were slow back then. The typical cycle is charge corona, writing (laser, or led raster scan), developing (toner) transfer(transfer corona) and cleaning (discharge corona sometimes), and doctoring (scrape the remaining toner off with a silicone rubber blade). Repeat as eneded. Polarities and what optical range this are done are dependent on if the drum was selenium coated or the organic photoreceptor that Cannon wrapped the cartridge around. That belongs back with one of the threads that had NAPLPS in it or maybe WYSIWYG when WYGINS is the reality. No one prints at under 100 DPI. Maybe now with very high resolution color displays we see what we get but then the best CRT I ran in color was 1280x1024 and .27 dot pitch (about 70-80dpi) which is still coarse by then 300DPI standard. That meant the tube could not display (even in B&W) what the printer could. New we have displays that are easily better than 300dpi but printers can do 600dpi and maybe more. That doesn't even cover color. No build quality is better. We ( I was part of the team that developed the LN01, LN03 and LPS40 and LPS20 series at DEC) found that getting engines that could run at speed for 90 days without breakdown was a mechanical impossibility, we had customers prove it repeatedly. Back then the choices were Cannon, Ricoh, Xerox and in about that order of durability. Getting 200,000 to 300,000 pages between failure was the challenge and price was the other. To get to 40PPM (LPS40) a microVAX in the printer pushing a custom bitslice processor and a even more custom bitbliter so that a reasonably complex page set could be printed at 40PPM. That's what it took then. But the printer took postscript directly and printed up to B size pages with no page too complex issues. Now we have cheap fast cpus that can do that. This development was in the time frame of the "workstation" so the big VAX in the back was not always the factor. However the cost of even slow printers was high enough Then that shared resource was what the customer said. The price of a 8PPM printer then is far higher than a 20ppm color printer now. So the existence of timesharing was and is a red herring as big systems printers printed less graphics and small single users wanted all the printing capability.. Often the single user was a workstation of even then a PC with Hercules or early CGA video. Very custom, in assembler as excess overhead was painful and I had one of the uncommon 10mhz z80s. I did it mostly to prove a point but waiting hours per page was not practical. Doing hi res text only documents was easy and people were doing it tot he limits of what printers were available. Graphics just wanted more of everything by many orders of magnitude. Large ram was cost and speed issues but doable then. Code can overcome a lot of things but raw CPU speed was and is the prime solution (enter GPUs). FYI I still run that LJ4L as its durable and parallel interfaces to all my systems directly save for the latest PC with no IO save for USB ( PIC24 programmed for USB to parallel solution). Allison

On 11/9/2012 9:14 PM, Mouse wrote: Well not resolution issue, but font scaling. Windows seems to have lost TrueType somewhere on my machine. For what little C programing I do, fixed with fonts is what I want! Ben. PS. If people were happy with printer output, programs like TeX would not be here.

On 10/11/12 5:39 AM, Roger Pugh wrote: Yes, in the Mac world, some low end printers did the same thing. --Toby

On 11/10/2012 05:39 AM, Roger Pugh wrote: This is also how the NeXT printer works. It's an SX engine. It's surprisingly fast at rendering complex pages. -Dave -- Dave McGuire, AK4HZ New Kensington, PA

On 11/10/2012 10:17 PM, Mouse wrote: Oh yes, I had forgotten about the SPARCprinter. Very nice. This reminds me, I'm pretty sure the NeXT printer was actually run at 400dpi. -Dave -- Dave McGuire, AK4HZ New Kensington, PA

In a way, yes. In both cases, the major part of the electorncis fro a 'standard' pritner of that type is missing. The Amstrad PCW pritner interface is essentially the drive signals for the pritnhead solenoids and stapper motor widings (at least fo the dot matrix version). There leectroncis in thew printer is jsut the driver stages. The CX-VDO printe does have rather more electroncis in it than that, but what it doens;'t have is the formatter board to tapme commands and ata electroncis in a CX-VDO (and the SX-VDO for that matter) is the low-level stuff to cotnrol the motors (get them running at the right speed), sequence the clutches and solenoids to feed the paper properly, cotnro lthe fuser temparature, the laser intensity, and so on. The interface, as I described last night, is basically a few signals to start a new page adn then a signal to pulse the laser o nand off. So in both cases you ahve to genenrate precisely timed pulses at the interface conenctor to get the printer mechanism to do what you want it to. -tony

On 11/11/2012 05:01 PM, Tony Duell wrote: The NeXT printer, if memory serves, connects to the desktop machine via a DE9 connector. This suggests (at least I think it does) that there's another board in there that's talking to the DC controller...I don't think nine pins is enough for the whole "dumb" control interface, especially if there are high-speed differential signals in the mix eating up a pair of lines. -Dave -- Dave McGuire, AK4HZ New Kensington, PA

On 10/11/2012 01:15, allison wrote: I am a tech at a company called XEIKON. We manufacture color digital presses.. We print on rolls of paper of upto 50cm (20inch) at 1200DPI at speeds of 19 meters a min (about 60ft/min??). The presses are 5 colour on both sides.. Being roll fed presses we cant stop the press and wait for the data, LOTS of FPGA's are required to keep up the data stream. We are low end industrial, some of the expensive stuff like Kodaks Prosper of course need lots more.... Roger

On 11/09/2012 06:00 PM, Fred Cisin wrote: If memory serves, the drum coating was a completely different composition, it was even a different color. -Dave -- Dave McGuire, AK4HZ New Kensington, PA

On 10/11/2012 21:11, Tony Duell wrote: Laser printer toner tends to be mono component, that is it does not require a separate carrier or developer to transport it to the photoreceptor and is magnetic. Copier toner tends to require a separate carrier that is made of a coated magnetic powder. The Carrier is recycled and not consumed, but does wear out over time. Laser printers work by charging a light sensitive, semiconducting drum or belt, the charge will vary depending on the type of material used. The drum may be charged positive or negative. A laser or LED array will then erase certain parts of the charge on the photoreceptor, then depending on which and how much charge the toner carries it will stick to either the charged or discharged areas. These charges are always different even on m/c's made by the same company so toners are rarely the same between m/c's. Also fusing tempratures of these toners are different. not enough heat and you can rub the toner from the sheet, too much it sticks to the fusing rollers.. Roger

On 11/11/2012 21:57, Tony Duell wrote: Is ther eay reason in principle why a photocopier has to use a differnt fussing temperature to a laser printer. If so, what is this reason? -tony I dont think it matters whether its a copier or printer the fact is the faster machines dont use monocomponent. It will be a cost issue, mono toner costs more to make, the faster m/c's use more toner! But to answer your question about temperature, i can guess it that as the speed goes up you have a shorter contact time in the fuser to fuse the toner so the toner in the high speed printer/copiers have a lower melting point than the slower ones. I might be completely wrong tho.. ;) Roger

On 09/11/2012 19:45, Tony Duell wrote: Pretty much every type of printer or copier uses different photoreceptor/toner/developer/carrier. As these all work on electrostatic priniples things such as charge, spacing between components, materials used in consumables, fusing temps are all different. 11 years working at Xerox, 12 more years on toner based digital printing... Roger

I have three TI Silent 700s available to the first person that claims them. Two power up, third does not. The two that power up print, but not legible. If not claimed by Monday November 19th will go in the trash. No shipping - local pickup only. Contact me off-list for pics or with questions. ? Lee Courtney

On 11/06/2012 06:15 PM, Fred Cisin wrote: If can be done but painfully slow. However the base language is done just start with FORTH and add the graphic primitives. However ram is definitely an issue or you get page too complex failures. Its a matter of speed and available ram to manage for data. Postscript looks very much like and works like FORTH, the graphic operator add to it but the base language is still a stack language. So when you put a graphic object on the stack there better be room. Allison

On 11/06/2012 09:34 AM, Ethan Dicks wrote: How about writing an 8086/5150 emulator? You need only 640K of base RAM to hold programs--that leaves a bunch for emulation... (Ducks the brickbats) --Chuck

On 11/06/2012 10:44 AM, geneb wrote: I had correspondence with Valentin when he was working on this thing. What with cheap 32-bit MCUs, I questioned his use of the high-speed 8052 platform. He seemed to use it "just because", so I don't see why a P112 couldn't do a similar emulation. But, one really has to ask, to what end? --Chuck

On Tue, 6 Nov 2012, Chuck Guzis wrote: Because. No other reason is needed. :) g. -- Proud owner of F-15C 80-0007 http://www.f15sim.com - The only one of its kind. http://www.diy-cockpits.org/coll - Go Collimated or Go Home. Some people collect things for a hobby. Geeks collect hobbies. ScarletDME - The red hot Data Management Environment A Multi-Value database for the masses, not the classes. http://www.scarletdme.org - Get it _today_!