New answers tagged

1

I agree with what people are saying here, but the answer is not perfectly clear. To say that you cannot write to an EEPROM but only program it, is a bit odd. The datasheets for the EEPROM list how many write/erase cycles the EEPROM is rated for. They call it write. A good example that comes to mind is an Arduino UNO. The EEPROM is not set by the factory and ...


2

The first HP Laserjet only had 128K of memory. The first LaserWriter, released the next year, had 1.5M. It imaged pages in complete form when the appropriate PS command was received. This was its big advantage over the HP machines, allowing it to construct more complex graphics. That did not last long, however, as improvements to the HP printers and PCL ...


2

Anecdote reinforcing how much they broke things up due limited memory. This was from a page layout printing program, full page of real estate advert text to which they manually fixed high res photos of houses then photo-reproduced the lot. (I'm sure many of you have seen such paper magazines outside real estate agents). This was a solution replacing manual ...


2

Back in 1991 we had an HP LaserJet with a very small amount of memory. It was sold as "software rendering" (or something like that). We bought it because it was way cheaper than the standard model. We didn't have too much money, and heck... we wanted a laser printer! The thing is, all the image was rendered as bitmap in the workstation, not in the ...


6

First of all, don't underestimate what can be done with 128K of memory. The original LaserJet was released in the era of the IBM 5150, whose base configuration had only 16-64K memory. As another comparison, the original Game Boy handheld had just 4K of memory and game cartridges were as small as 32K, yet were capable of doing quite a bit graphics-wise. They ...


1

The statement "Laser printer operate in a line by line base" is very misleading. (I'd make this a comment on that answer, but StackExchange won't let me). Yes, they might have had a mode of operation to emulate line printers and dot-matrix printers, but that's not their intrinsic behaviour. And the timelines seem a bit out too. I first had access ...


10

They simply didn't let you send much of a bitmap The first HP LaserJet printers on the market required you send jobs via PCL language. The language was tuned to pretty much not let you do anything the printer couldn't handle. PCL for the whole page needed to fit in the very limited RAM. Needless to say, PostScript was out of the question on these early ...


7

The NeXT Laser Printer had no memory, but a fast non-standard interface fed it bits from its NeXTcube. The NeXT hardware architecture was built around a flexible multichannel DMA controller, so it was really efficient at copying bits from one place to another.


2

A conventional flip flop requires the following: Two inverting switching elements that will strongly pull their output in the direction opposite what's required to turn them on. Two elements that can weakly pull the output of whichever switching element isn't on in the opposite direction. Two elements that, in response to external stimuli, can pull those ...


5

But I'm used to a flip-flop being made of six transistors, which suggests it would need six triodes, Not really, a basic flip flop does not need 6 transistors. maybe there's a mix up with RAM cells? Two will do it quite fine (*1,*2). Similar the two triodes of a 6SN7 is all what's needed - well, plus two rather equal resistors between them and another two ...


11

To add to the other answers: Under Windows and GEM, printer drivers could store the current page as a metafile and rasterize it repeatedly as a series of horizontal bands, each band being large enough to fit into printer memory. This was slower than sending the data directly to the printer (since each page had to be rasterized repeatedly) but allowed an ...


26

In addition to Raffzahn's usual excellent answer, a few important things to note: PCL still exists. You can (I do...) still write software that sends simple PCL commands to a printer to select fonts, print text, etc. Sending an entire page, of text, as a bitmap to a printer is the way GDI printers work - and is a Very Bad Thing. The original HP LaserJet ...


42

To print an area of 7.5 by 10 inches at 300 DPI requires 844K if it's kept as a single bitmapped image. Does it? Maybe. Then again one cold think of many simple ways (like RLL) to compress a rendered image fast and decompress it at a speed quite capable to keep up with the print-'head'. Obviously they were doing something clever to minimize the hardware ...


9

Looking at the Wikipedia article on the LaserJet, it looks like the printer couldn't rasterize a whole page of graphics and you needed a 512K LaserJet Plus to be able to do graphics covering most of a page. That would mean the controller would be rasterizing text to the drum using the built-in ROM raster fonts. The LaserJet Plus followed in September 1985, ...


6

[Since not closed by now, I'll try to give it a historic spin] Hold Your Horses In some way this is a case of second step before the first, or at least it seems like. Thinking about how to swap segments, do caching or whatsoever is about implementation. There are many ways to do so, not at least shown by various home computers. But I belive this would fall ...


20

Quote from VICE manual: Load the specified file into memory. If no address is given, the file is loaded to the address specified by the first two bytes read from the file. If address is given, the file is loaded to the specified address and the first two bytes read from the file are skipped.


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