# HELP! I have this old plotter, see.... **URL:** \ **Category:** Factual Questions\ **Created:** [May 18, 2003, 8:23pm UTC](https://boards.straightdope.com/t/help-i-have-this-old-plotter-see/176105 "2003-05-18T20:23:46Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![TBone2](https://avatars.discourse-cdn.com/v4/letter/t/6a8cbe/32.png) [@TBone2](https://boards.straightdope.com/u/TBone2)\ **Post date:** [May 18, 2003, 8:23pm UTC](https://boards.straightdope.com/t/help-i-have-this-old-plotter-see/176105/1 "2003-05-18T20:23:46Z")
A friend of mine has recently come into possession of a relic of the 80’s – an IBM Model 7374 8-pen color plotter. Being the good buddy he is – and as incompetent with computers as anyone I’ve ever known – he decided that it would look better taking up MY floor space than it would taking up HIS. So… Where do you go for information on something like this? IBM’s web presence would lead one to believe that they never even thought about making such a thing. I’ve found a few references that claim that this dinosaur will emulate an HP 7580A plotter, but the HP driver bundled with WinMe doesn’t seem to work. The only other references I can find to drivers for it indicate that OS/2 supported it, but that’s a dead end too. (I’m not going to set up a new system to run OS/2 just to see if my buddy’s $4 plotter works. Yeah, he got it for four bucks at an auction.) Any ideas where to look for drivers, documentation, ANY information? ---
**Author:** ![Padeye](https://avatars.discourse-cdn.com/v4/letter/p/a9a28c/32.png) [@Padeye](https://boards.straightdope.com/u/Padeye)\ **Post date:** [May 18, 2003, 8:49pm UTC](https://boards.straightdope.com/t/help-i-have-this-old-plotter-see/176105/2 "2003-05-18T20:49:58Z")
You may have a white elephant as I found with an HP pen plotter I bought surplus. I could never find a windows driver for HPGL-1 which doesn’t support primitives. You may have luck with a high end program like autocad which has its own printer drivers but I don’t think you’ll find a universal driver. ---
**Author:** ![Cillasi](https://avatars.discourse-cdn.com/v4/letter/c/71e660/32.png) [@Cillasi](https://boards.straightdope.com/u/Cillasi)\ **Post date:** [May 18, 2003, 9:04pm UTC](https://boards.straightdope.com/t/help-i-have-this-old-plotter-see/176105/3 "2003-05-18T21:04:15Z")
According to this, about $25 [http://search.ebay.com/search/search.dll?cgiurl=http%3A%2F%2Fcgi.ebay.com%2Fws%2F&krd=1&from=R8&MfcISAPICommand=GetResult&ht=1&SortProperty=MetaEndSort&query=8-pen+plotter](http://search.ebay.com/search/search.dll?cgiurl=http%3A%2F%2Fcgi.ebay.com%2Fws%2F&krd=1&from=R8&MfcISAPICommand=GetResult&ht=1&SortProperty=MetaEndSort&query=8-pen+plotter) but it’s not an IBM. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [May 18, 2003, 9:07pm UTC](https://boards.straightdope.com/t/help-i-have-this-old-plotter-see/176105/4 "2003-05-18T21:07:41Z")
I found out that plotter is emulated by the HP 7580 (or vice versa). Haven’t found a driver for either one, but at least you now have a second avenue of search. ---
**Author:** ![TBone2](https://avatars.discourse-cdn.com/v4/letter/t/6a8cbe/32.png) [@TBone2](https://boards.straightdope.com/u/TBone2)\ **Post date:** [May 18, 2003, 9:10pm UTC](https://boards.straightdope.com/t/help-i-have-this-old-plotter-see/176105/5 "2003-05-18T21:10:17Z")
> [@](#): > > \*Originally posted by Cillasi \* > \*\*According to this, about $25 > > [http://search.ebay.com/search/search.dll?cgiurl=http%3A%2F%2Fcgi.ebay.com%2Fws%2F&krd=1&from=R8&MfcISAPICommand=GetResult&ht=1&SortProperty=MetaEndSort&query=8-pen+plotter](http://search.ebay.com/search/search.dll?cgiurl=http%3A%2F%2Fcgi.ebay.com%2Fws%2F&krd=1&from=R8&MfcISAPICommand=GetResult&ht=1&SortProperty=MetaEndSort&query=8-pen+plotter) > > but it’s not an IBM. \*\* No, it’s not an IBM, and you musta missed the _$70_ S&H fee!!! Thanks just the same! Maybe I wasn’t clear enough… I already have this gigantic plotter sitting right here next to me. I’m hoping to be able to find information about it – drivers, manual, DIP switch settings, etc. – that will convert it from a well-made electric doorstop into a machine that produces drawings. ---
**Author:** ![TBone2](https://avatars.discourse-cdn.com/v4/letter/t/6a8cbe/32.png) [@TBone2](https://boards.straightdope.com/u/TBone2)\ **Post date:** [May 18, 2003, 9:22pm UTC](https://boards.straightdope.com/t/help-i-have-this-old-plotter-see/176105/6 "2003-05-18T21:22:55Z")
> [@](#): > > \*Originally posted by Q.E.D. \* > \*\*I found out that plotter is emulated by the HP 7580 (or vice versa). Haven’t found a driver for either one, but at least you now have a second avenue of search. \*\* Yeah, as I mentioned in my OP, I caught the HP 7580-emulation thing. I’m running Win Me, which has a bundled driver for the HP 7580A, but it doesn’t seem to do much. This thing is one cool piece of hardware! Lotsa lights and buttons, even a joystick on the front panel that lets you make your own drawings. It would be slick to teach this Neanderthal to speak English, ya know? ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [May 18, 2003, 10:13pm UTC](https://boards.straightdope.com/t/help-i-have-this-old-plotter-see/176105/7 "2003-05-18T22:13:17Z")
> [@](#): > > Being the good buddy he is – and as incompetent with computers as anyone I’ve ever known – he decided that it would look better taking up MY floor space than it would taking up HIS. I would say he is a very intelligent man. 😃 Umm… your best (or at least easiest) bet is to get a null modem cable and see if you can communicate with the unit via a serial port. BTW I think the IBM 7374 may well _be_ the HP 7580 internal hardware wise. Try these DIP settings and see if they work with a null modem cable and 7580 emulation. Dip switch settings for the specified printer: At com port set 9600 baud rate use the following dip switch settings: 1 UP 2 UP 3 UP 4 DOWN 5 UP 6 DOWN 7 UP 8 DOWN 9 UP 10 UP Switch settings on plotter: INTERFACE MODE: RS-232-C Dip switches: EXPAND --X NORMAL EMULATE --X NORMAL STAND ALONE X-- EAVESDROP MONITOR MODE --X NORMAL LOCAL --X NORMAL PARITY ON --X OFF OFF --X ODD DUPLEX-HALF X-- FULL HARDWIRE X-- MODEM DTR BYPASS X-- NORMAL Here are [some communication tips](http://www.mutoh.com/tkpl_rs2.htm). It’s for a different series of plotters but the idea is the same. [sub] > [@](#): > > If Windows System Printer drivers ‘test page’ does not print but there are errors displayed on the plotter then consult the Microsoft help menus for printers paying particular attention to the serial IRQ of the port you are connected to since the plotter requires a dedicated IRQ that cannot be shared with any other devices ( fax / modem, network card, etc. check them all ). See other sections below also. > > Windows wants to see serial connections 9600, 8,n,1 protocol Xon/Xoff make sure that the plotter and your Windows comport settings agree. XP models use Default 4 in the plotter. As a side note: (DOS programs used to be set for 9600, 7 data bits, even parity and 1 stop bit but of course Windows wants to see it differently. These parameters are Default 3 in the plotter). If you cannot get around having to use two different sets of parameters then try using different ‘users’ ( the plotter function that allows for entirely different sets of parameters to be retained in the plotter and then selected by choosing “User” 1,2,3, or 4). > > The language of the driver and emulation as well as communication settings are the usual reasons that errors occur. > > If those items are correct and errors are still reported from either the computer software or the plotter then recheck all IRQs for sharing (which the plotter cannot share its IRQ) and computer comport connectors to ensure connection to a valid functioning port. Remember that the cable must be a ‘null modem’ cable. Always buy a 25 to 25 cable and if you need it stepped down to your serial port 9 pin connector then use a standard serial ‘mouse’ adapter. > > If you never get any error messages on the plotter then you must question the connectivity of your plotter to the computer. These can be one of three possible things. > > The Comport of the computer. Is it enabled and/or the correct Com1 or Com2? > > The cable and/or adapter. Are you using a ‘null modem’ cable and a standard serial mouse adapter? > > The plotter transmit and receive circuitry. Has the plotter, computer, or building been hit with a large voltage spike of some kind? Like maybe lightning or a power surge (a brown out). > As a test of connectivity here is a simple test that you can try. To check the connection between the plotter and the computer. > > Get to a DOS prompt C:> > > At the C:> Type Copy config.sys com1 or com2 and when you press ENTER the plotter should give you an error message. This confirms continuity of the port, cable and receiving chips in the plotter. If you get no error then you must question all three of those items. > > Without the continuity ‘error’ message then all other attempts at setup will be useless. All suggestions included in this e-mail assume that you have continuity between the plotter and the computer. [/sub] ---
**Author:** ![TBone2](https://avatars.discourse-cdn.com/v4/letter/t/6a8cbe/32.png) [@TBone2](https://boards.straightdope.com/u/TBone2)\ **Post date:** [May 18, 2003, 11:19pm UTC](https://boards.straightdope.com/t/help-i-have-this-old-plotter-see/176105/8 "2003-05-18T23:19:47Z")
**astro** , my hero! However, this IBM monstrosity doesn’t want to talk nice to me – or to you! There are only four DIP switches on the back of this one, like this: PARITY ON – PARITY OFF PARITY EVEN – PARITY ODD EMULATE – NORMAL EXPAND – NORMAL In addition, there’s a tiny li’l black push-button labeled “Conf. Test.” And a rotary switch that selects baud rate, which is set, I think correctly, at 9600. Perhaps a letter to IBM’s CEO would be in order… ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [May 19, 2003, 12:14am UTC](https://boards.straightdope.com/t/help-i-have-this-old-plotter-see/176105/9 "2003-05-19T00:14:17Z")
Some possible things to check - 1: Are you absolutely sure the cable you are using is a _null modem_ cable vs a straight through serial cable? 2: Is the windows com port you are using set to 9600, 8,n,1 protocol Xon/Xoff 3: You might also shifting these two DIP switches below back and forth and try making it “parity off” and “parity even” settings first PARITY ON – PARITY OFF PARITY EVEN – PARITY ODD [Some HP plotter communications advice](http://www.hp.com/cposupport/plotters/support_doc/bpp01367.html) [sub] > [@](#): > > Verifying Communication > > 1. Turn on the computer and load DOS. > > 2. At the DOS prompt, type in the following. > > MODE COM1:9600,N,8,1,P > > Press the ENTER key on the computer keyboard. This will set your computer’s RS-232-C serial port for 9600 baud, no parity, 8 data bits, one stop bit and specify hardwire handshake with continuous retry. > > 1. Type the following: > > ECHO IN;SP1;PA0,0;PD1000,1000;SP0;PG;\>COM1 > > 1. Press ENTER. The plotter should draw a diagonal line on the page. > > NOTE: Type in the ECHO statement exactly as shown. The only space in this statement is after the word “ECHO.” [/sub] ---
**Author:** ![CurtC](https://avatars.discourse-cdn.com/v4/letter/c/ce73a5/32.png) [@CurtC](https://boards.straightdope.com/u/CurtC)\ **Post date:** [May 19, 2003, 3:40am UTC](https://boards.straightdope.com/t/help-i-have-this-old-plotter-see/176105/10 "2003-05-19T03:40:39Z")
> [@](#): > > _astro wrote:_ > BTW I think the IBM 7374 may well be the HP 7580 internal hardware wise. I was in the HP factory in San Diego, where they made their plotters, in the early 80s. There I saw large-format plotters being made with the letters “IBM” silkscreened onto them instead of “HP.” This would have been right around the time the 7580 was a current model. ---
**Author:** ![TBone2](https://avatars.discourse-cdn.com/v4/letter/t/6a8cbe/32.png) [@TBone2](https://boards.straightdope.com/u/TBone2)\ **Post date:** [May 20, 2003, 9:30pm UTC](https://boards.straightdope.com/t/help-i-have-this-old-plotter-see/176105/11 "2003-05-20T21:30:10Z")
Success, folks!!! And thanks to one and all!!! Yes, the null modem bit was the trick I had missed. BTW, a null modem adapter from Radio Shack worked with the straight serial cable I was trying to use. So far, I’ve been able to print out the standard Windows printer test page successfully. Now to try and make the thing work well enough to produce a drawing of some sort! ---
**Author:** ![TBone2](https://avatars.discourse-cdn.com/v4/letter/t/6a8cbe/32.png) [@TBone2](https://boards.straightdope.com/u/TBone2)\ **Post date:** [May 20, 2003, 11:38pm UTC](https://boards.straightdope.com/t/help-i-have-this-old-plotter-see/176105/12 "2003-05-20T23:38:26Z")
::::::::::UPDATE!!!:::::::::::: As previously stated, using the bundled driver for the HP 7580A, the plotter successfully printed the test page. I downloaded Design Workshop Lite, a pretty nice CAD program, and drew something simple – essentially straight lines at various angles – in two dimensions. The plotter reproduced it precisely. I created another 2D drawing using some curves and such, and the plotter reproduced it, sorta. It drew part of it great, but then, like, forgot what it was doing and dragged a straight line right off the page. This happened several times. I downloaded an actual architectural 3D rendering of a fairly standard house, called up a 2D plan view, and tried to print that, but the results just get weirder. The first shot, it drew part of it in recognizable form. Later attempts were completely unsuccessful, with the plotter drawing straight lines at odd angles radiating from a central point, banging away for 10 or 15 minutes until the pen had torn a hole in the paper at the central point. I’m wondering if it’s a compatibility/software issue. I’m also wondering if it’s a cabling issue. I’m also wondering if this IBM 7374 is truly an HP 7580A at heart. And I’d give my left nut (maybe) for a user’s manual for this antique. Any ideas? ---
**Author:** ![Mr.Blue\_Sky](https://avatars.discourse-cdn.com/v4/letter/m/d26b3c/32.png) [@Mr.Blue\_Sky](https://boards.straightdope.com/u/Mr.Blue_Sky)\ **Post date:** [May 20, 2003, 11:52pm UTC](https://boards.straightdope.com/t/help-i-have-this-old-plotter-see/176105/13 "2003-05-20T23:52:46Z")
Is there any indication on the plotter where it came from? That could be a place to start. Check with your local IBM office (if you have one). You might luck up and find an “old timer” who could scrounge around and find a manual. ---
**Author:** ![peajay](https://avatars.discourse-cdn.com/v4/letter/p/85e7bf/32.png) [@peajay](https://boards.straightdope.com/u/peajay)\ **Post date:** [May 21, 2003, 8:10am UTC](https://boards.straightdope.com/t/help-i-have-this-old-plotter-see/176105/14 "2003-05-21T08:10:46Z")
> [@](#): > > \*Originally posted by TBone2 \* > \*\*It drew part of it great, but then, like, forgot what it was doing and dragged a straight line right off the page. This happened several times. > > Any ideas? \*\* Sounds like it may be a flow control issue. Try adjusting your windows serial port settings. Set the FIFO settings to 1 byte. This might be causing a problem since when the printer signals that it’s buffer is full there’s still 15 bytes left in the output buffer that are going to go to the plotter. The thing is old, they probably didn’t have FIFO buffers to plan for back then and it might send XOFF when there’s only four bytes of buffer left, to make best use of the small buffer it likely has. (RAM was expensive back then.) Also make sure everything is set up to use the same kind of flow control. Nothing worse that using hardware flow control on a plotter that only does XON-XOFF. If all else fails, try a lower baud rate.