neff@hpvcfs1.HP.COM (Dave Neff) (04/14/89)
I have been getting allot of mail about the DeskJet+ so I wanted to post this information to answer common questions. Here is a summary of the technical differences between a DeskJet and a DeskJet+. 1. The DeskJet+ has an 8MHZ Z180 processor with 64K of RAM and 256K of ROM. The DeskJet has a 4MHZ Z80 processor with 32K of RAM and 128K of ROM. 2. The DeskJet+ has a new paper motor that runs twice as fast. 3. The DeskJet+ has a different "sled" which allows a better priming algorithm. Note: These three facts imply that the basic parts needed to upgrade a DeskJet are 1) a new logic board, 2) a new paper motor, 3) a new sled. This also implies an upgrade is not simple and it would be easy to blow up a power supply, smoke the new logic board, and break a part of the sled assembly. On the other hand, I, a mere CS type have upgraded 2 DeskJets to DeskJet+s and haven't broken or blown up anything yet. 4. The DeskJet+ has twice as large an addressing space allowing for twice as large ROM and RAM cartridges. Hence there are new DeskJet+ only font cartridges and there is a 256K DeskJet+ RAM cartridge for soft fonts. (By the way, the DeskJet+ will download soft fonts about 4 times faster than the DeskJet). 5. Due to the increased processor speed, increased RAM, and some other hardware/software tweeks the DeskJet+ will print graphics from the Centronics port 5 times faster than a DeskJet. When the serial port is used the DeskJet+ graphics speed is limitted by the baud rate, not the printer. WARNING: Your application probably cannot generate graphics data as fast as the DeskJet+ can accept it unless you are using a very fast PC or some very smart software. Hence the actual "speed up" relative to a DeskJet is host and application dependant. The maximum rate a DeskJet+ can do a page of 300DPI graphics is just about 1 page per minute. The DeskJet could do 1/5 a page per minute (a page in 5 minutes). 6. Simple text is printed at 120CPS on both the DeskJet and the DeskJet+. However the DeskJet+ can keep up with this maximum rate in more complex cases (multiple fonts in a pass and so forth) as well as pick up and move paper faster. Both the DeskJet and DeskJet+ are rated at 2 pages per minute for text, but the DeskJet could only really do the most simple text at this rate whereas the DeskJet+ can do more complicated text at the same 2PPM rate. 7. The DeskJet+ has landscape mode built in, this is optional on the DeskJet. WARNING: The landscape support on DeskJet was intended for printing simple spreadsheets. There is no support for mixed text and graphics in landscape mode nor is there support for proportionally spaced landscape fonts via font cartridges. Hence if you primarily want a printer to do fancy spreadsheets with nice proportionally spaced text in landscape mode you would be better off with a laser printer. The technical reason proportional spaced landscape fonts are not possible is due to a hardware limitation of the chip that actually reads the font cartridges and renders the image on the page so there is not a software tweak I can make to workaround the problem. Hence if you get a DeskJet or DeskJet+ you should "write off" ever expecting to do anything real fancy in landscape mode unless its graphics only. Now the DeskJet+ does do nice fancy spreadsheets (i.e. via Excel) in portrait mode, but not landscape. This warning only applies to applications and hosts that render text with the built in fonts. Hosts such as an Atari which only send out graphics and render the text images internally do not suffer from this same problem since in this case the printer only sees graphics and the PC does all the work of rotating, scaling, and so forth. 8. Due to changes in the internal hardware, the DeskJet Epson FX80 emulation cartridge will not work in a DeskJet+. There is a DeskJet+ version of this cartridge. This Epson emulation cartridge will print graphics 3 times faster than the original DeskJet emulation cartridge (which was comparable in speed to the actual Epson FX80). 9. The DeskJet+ supports internal fonts of up to 30 point, whereas the DeskJet supported fonts up to 15 points (technically 36 point for the Plus and 18 point for the DeskJet are possible but these fonts must have no descenders). 10. There is no difference in print quality or waterfastness between the DeskJet and DeskJet+ since this is an ink cartridge, rather than a printer issue. The waterfastness issue is getting allot of attention and eventually there should be a new waterfast ink cartridge that can be plugged into the DeskJet family printers but I cannot make promisses or give any time frames. 11. The DeskJet+ will retail for $995 and the DeskJet will now retail for $795. This is not a technical difference but it is significant. Personally, if you factor in the cost of a landscape cartridge for a DeskJet and an "A" (courier italics) cartridge which are both built in to the DeskJet+ the price difference is negligible. On a related note, we have price reduced our font cartridges by about 30%. Presently there is no plan to offer an official upgrade to convert DeskJets into DeskJet Plusses. A supported upgrade would be expensive relative to the cost of the printer (could easily be close to $400). Although an unsupportted unofficial "roll your own" upgrade would be possible it would have no warranttee, and if you hook up a cable wrong and smoke a board you would have to pay again for any part you smoked. Servicing such an unofficial upgrade might be difficult, however it would be hard to tell the difference between a properly upgraded DeskJet and an actual DeskJet+. Also if you use the DeskJet Epson cartridge you would need to buy a new DeskJet+ Epson cartridge. I hope this answers most of your questions. I have been getting a flood of mail about the DeskJet+ which is fine but it has been keeping me quite busy. Dave Neff hp-sdd!hpvcla!neff