The 1520 Plotter Survival Guide

[airship]

The 1520 Plotter Survival Guide

THE COMMODORE 1520 PLOTTER

The 1520 was the only plotter Commodore ever made, and it was essentially a toy. You can see pictures and read a little bit about it here:

http://www.zimmers.net/cbmpics/peserial2.html

It came in at least three different versions: off-white with a black plastic paper roll cover, brown with a black plastic paper roll cover, and brown with an open paper roll holder with no cover.

Parts are hard to come by, and that was the inspiration for me to write this survival guide.

PAPER

The roll paper used by the 1520 is a fairly obtainable office supply item, so it's the only thing you're likely to be able to find relatively easily. It's just 4 1/2" wide x 3" diameter adding machine roll paper ('bond', not thermal!) with a cardboard center tube. (This just happens to be the same width as toilet paper - but don't be tempted to use THAT!) Problem is, it's not a standard off-the-shelf adding machine paper size. Staples and Office Depot don't carry it, and most business suppliers want to sell you a case of 50 or 100 rolls at a time. Nobody will sell you a single roll. About the most reasonable I've found is to buy a box of 10.

Here's a list of real-world machines that use the same paper. If a roll says it fits these, it will most likely fit your 1520, as well:

Hamilton-Test Micro T/TS 1000 & Petrosonic 111 Star 312 DP-8340 Hamilton Test System Data Saab 5808-3 Petrolsonic III printer Squirrel Squirrel POS systems Petrovend Petrolsonic Racal-Transcom RG Fast 2000 Squirrel Squirrel POS systems Westrex 4900, POS2000 80 column printer, S600, S610, S7000, S830 80 column printer Star Micronics DP-824 (40 column), DP8340 series, DP8340FM, DP8340SM Unisys EF4260 Westrex 4900, POS2000 80 column printer, S600, S610, S7000, S830 80 column printer (No, I couldn't figure out where the model number breaks should come, either!)

The following site has rolls for $22.98 per box of 10, plus shipping (disclaimer: I've never ordered from them personally):

http://ezpaysys.com/412inx1951pl.html

But this site has boxes of 25 rolls for $27.55. Of course, shipping will be at least 2 1/2 times more, and who can do that much plotting on a 1520? (I've never ordered from these guys, either):

http://www.paperrollsplus.com/thermal%20paper%20rolls.htm

For a supplier that will sell you two rolls at a time for $3.95, see B&C Computervisions, below.

PENS

Here are images of the 1520 plotter pens. The first is a dimensioned drawing, to hep you figure out if other pens are close enough to work. The second is a photo of the package in which the pens were shipped.





The following plotters all use the ALPS mechanism. They are NOT identical in their controller or interface logic - they merely use the same cheap ALPS drop-in plotter unit. (Numbers which follow each entry are the manufacturer's original part numbers for replacement pens.) Hopefully this will aid you in your quest for pens.

Commodore 1520
Tandy CGP-115
   26-1480a
   26-1481
Sharp CE-150
   EA-850B - 4 black pens
   EA-850C - 4 color pens (black, blue, green, red)
Atari 1020
   BX4206
Mattel Aquarius 4615
TI-99 HX-1000
     1000BL

As of this writing, the following two vintage Atari dealers claim to have pens available for the prices shown. Be aware that these are NOS (New Old Stock) 20-year-old pens, and though they both claim to test first, customers have reported that it's a crap shoot as to whether you'll get pens that actually work. (B&C Computervisions also says they have replacement 'revolver' pen holders and paper.)

Best Electronics
http://www.best-electronics-ca.com/
Page 148 of their catalog:
     Atari 1020 BX4204 Color Pen Set (4 pens per set) $3.00 (Limit One set per customer)
     Atari 1020 BX4206 Black Pen Set (4 pens per set) $3.00

B&C Computervisions
http://www.myatari.com/
     PRA082   WHEEL 1020 PEN HOLDER             $1.95
     SUA001   PAPER 1020 - 2 ROLLS                 $3.95
     SUG506   PENS 1020 BLACK (set of 4 pens) $3.00
     SUG507   PENS 1020 COLOR (set of 4 pens) $5.00

It seems the same pens were used in some medical equipment, which is why a German firm still sells high-quality precision replacement pens. They're expensive, and probably overkill for the 1520, but at least they're available.

The Sharp User Group (http://www.sharpmz.org/index.html) tracked them down, and here's what they say about them:

The times of searching for this very rare item are over! The sets of plotter ball-point pens EA850B and EA850C usable for the MZ-1P01 and MZ-1P16 are now again available. The German company "Christiane Lass" developed the equivalent set which is now waterproof (the original SHARP set is not). I got the following message from the company:
"The pens correspond actually accurately to the defaults of the models EA850C and EA850B including the crucial ball point. We worked at the project nearly 1 year; and first we experimented with a fiber tip, but this wasn't acceptable by the technical examination of international medical technology manufacturers. We now sell the current version to Scandinavia and into the USA with no objection. Our actual emphasis lies in the medical technology but the pens are also usable for computer plotters."
Really, they are! I could test a free set. See the result on the picture. The company sells the pen sets internationally and has 2,000 sets at its stock. Contact Christane Lass by email: Christiane.Lass@t-online.de if you want to get more info or if you want to order the set(s). Price: Euro 12.70 plus shipping costs Euro 5.00 for Germany. Please ask for the shipping costs outside of Germany.

There's even a picture:


This medical supplier in Switzerland also has them, but they want you to ask for a quote so I'm sure they're not cheap there, either:
     http://www.diagramma.com/1520--Comodore-.13+QSoqMjc2M3xMKioy.0.html?L=2

IMPORTANT TIP: As hard as these pens are to find, follow Commodore's advice - REMOVE the pens and cap them in between uses. It's stupid, and it's a hassle, but just DO IT!

PARTS

The ALPS plotter mechanisms are very fragile, and the cheap plastic gears have a tendency to break. As stated above, B&C Computersisions claims to have replacement pen holders (the 'revolver' mechanism) for $1.95 each.

But Electronic Goldmine (http://www.goldmine-elec.com/) currently has the entire mechanism as a surplus part:

ALPS 4 Color Head Assembly - $1.49
http://www.goldmine-elec-products.com/prodinfo.asp?number=G15824

4 Color Pen Printhead by ALPS - $3.95
http://www.goldmine-elec-products.com/prodinfo.asp?number=G2092

Electronic Firing Mechanism - $3.49
http://www.goldmine-elec-products.com/prodinfo.asp?number=G2093

The first item is the chassis stripped of the revolving pen holder and pen-down solenoid. The second is the entire mechanism. The third is the pen-down solenoid only. (Note that they're selling the solenoid for almost as much as the entire mechanism - apparently they've decided it's a good part for robotics hobbyists.) I have no idea how hard it is to repair these. Considering how tiny and fragile they are, I'd go the route of replacing the entire mechanism if you can.

It's held in by two easily-accessed phillips screws from the top of the 1520. Take them out, disconnect the ground wire (another philllips screw), unplug the mechanism from its connector, and it's out. Reverse the process with your new mechanism and you're done.

Before you replace the mechanism, you might want to try a drop of sewing machine oil on the motor and gear hubs and on the pen holder slider. DO NOT get any oil on the platen roller or anywhere else!!! My 1520 was totally frozen up when I got it, so I figured I had nothing to lose by carefully applying a couple of drops of oil. I even bravely turned the gears a bit by hand to get things loosened up. I DO NOT recommend you do this with a working 1520 mechanism - the old adage "If it ain't broke, don't fix it" certainly applies here.

I have just ordered four of the entire replacement mechanisms from Electronic Goldmine. Why four? I've read online that as many as 3/4 of these may have bad gears. While my 1520 still works, sort of, it is flaky at best. I'm trying to make sure I have the parts to keep it running well into the future. I figure this will probably be my last chance to order replacement parts.

If you insist on trying to repair it yourself, here's an exploded view of the ALPS mechanism from a Tandy computing site:

http://support.radioshack.com/support_accessories/doc10/10508.pdf

(If you back up a bit on this site to http://support.radioshack.com/support_accessories/5632.htm you'll find the entire user's manual for the Tandy plotter.)

CONTROLLER

The MPU (not CPU) in the 1520 is a special 6502 (yes, another one) made by MOS which has 2K of mask-programmable ROM on board along with 64 bytes of RAM (in zero page, of course) and a UART. (Mask-programmable means the ROM is programmed when the chip is made, so it's not reprogrammable at all.) It's called the 6500/1 and its Commodore part number is 325340-03. Here is the 14-page PDF data sheet for the 6500/1 (make sure you back up a level and check out ALL the MOS chip data sheets this guy's got!):

http://highgate.comm.sfu.ca/~rcini/classiccmp/pdf/ds_6500.pdf

With all this going on, it's no wonder the 1520 board is so bare - no ROM, no 6522 or 6526, nada. Just a couple of interface chips for the stepper motors and some transistors to drive the pen solenoid. The 1520 schematic is available here:

http://www.zimmers.net/anonftp/pub/cbm/schematics/printers/1520009.gif

Am I the only one thinking, 'Hey! The 1520 board's got all the logic, controllers, and interfacing to let it drive ANY TWO compatible stepper motors AND a solenoid!"?

SOFTWARE

I'm still looking for a D64 image of the original disk that shipped with the 1520 (if any), Does anyone have this?

There is apparently not one but a suite of GEOS printer drivers for the 1520, though I haven't found a link to them: 1520 40 Black, 1520 40 Blue, 1520 40 Green, 1520 40 Red, 1520 10 Col., 1520 20 Col., 1520 80 Col.

You can buy them all (along with several other GEOS printer drivers) on a $4 public domain disk here:

http://oldsoftware.com/64pd.html

I don't know if they're on the GEODRIVERS1 disk that Click Here Software sells for $8 here or not:

http://cmdrkey.com/cbm/pricelists/prices.html

And they might be on the Shell printer driver disks that are available for free download here, though I don't know for sure:

http://www.filegate.net/cbm/g-disks/

There are a dozen or so disks and individual BASIC programs for the 1520 at the GEnie Information Networks archive at:

http://cbmfiles.com/genie/C64SoftwareListing.html

COMAL has good support for the 1520, and there are several demos that use COMAL turtle graphics with the 1520 to good effect. The best COMAL download site I've found is the COMAL Archive (which includes a disk dedicated solely to the 1520)  at:

http://users.macunlimited.net/kenross/INDEXC.HTML

Of course you'll probably stumble across the occasional program for the 1520 on other Internet archive sites now and again, but they are rare birds.

MANUALS & BOOKS

Project64 doesn't have the 1520 Printer/Plotter User's Manual, and I can't find it anywhere else on the web for free either, though you can buy it here in PDF format for $15.99:

http://www.manuals-in-pdf.com/1520-p-225051.html

I'll scan my paper copy (eventually) and put it online if I can't find it elsewhere.

1520 User's Manuals also come up for sale every once in awhile on eBay, as does the 1520 itself, of course.

Zimmers has a command summary:

http://www.zimmers.net/cbmpics/cbm/printers/1520.txt

I haven't been able to find any indication that there was ever a 1520 Plotter technical manual, except for the fact that the schematic exists. If you know of one, let me know.

Issue 8 of Commodore Techtopics discussed how to change the device number of the 1520. I haven't been able to find a copy online, though the schematic (above) makes it clear that it's the standard CBM 'cut a jumper' method, with three jumpers. The 1520 ships with a default device number of '6'.

The only book I've found that talks about the 1520 is Abacus' Commodore Peripherals: A User's Guide, which seems to have a chapter dedicated do it. I don't own this book, so I can't say if it actually provides any useful information over and above what's in CBM's 1520 Printer Plotter User's Manual.

THAT'S IT

I hope you've found this helpful.

If you have any other 1520 information, please add it to this thread.

[RobertB]

[I hope you've found this helpful.

Thanks, Mark.  A good listing of resources for the 1520.

I should pull mine out of the box,
Robert Bernardo
Fresno Commodore User Group
http://videocam.net.au/fcug
The Other Group of Amigoids
http://www.calweb.com/~rabel1/

[Guest]

My first printer was a 1520 that I used with my VIC-20.  It's kinda neat because the 1520's output was wider than the VICs, so it was actually useful.  You could print "long" lines of BASIC and debug much more easily with this guy.  Of course, it took 20 minutes to print a 3K BASIC program....

[Blacklord]

My first printer was a 1520 that I used with my VIC-20.  It's kinda neat because the 1520's output was wider than the VICs, so it was actually useful.  You could print "long" lines of BASIC and debug much more easily with this guy.  Of course, it took 20 minutes to print a 3K BASIC program....

I just got one of these of eBay - & it has three spare sets of NOS pens - haven't had a chance to play with it yet though.

Nice to see pens can still be had though.

Lance

[airship]

My eBay one came without any pens at all!

I'm still waiting for an email response from either of the Atari vendors above. I sent my emails late Friday, so I'm hoping they're just catching up from the weekend and it won't be a lifetime before they respond. If they take too long, I'll just fork out for the ones from Germany. *ouch!*

[wte]

Last week I got my thrird! The first was dead, the second had a broken gear but the electronic part seems to be ok. Both from ebay. Now my third is working perfectly (bought it from a sceener in the Forum64 including a lot of paper and original pens).

The 1520 Plotter Survival Guide is excellent. Thanks for that. I'm thinking about buying the new replacement pens (no problem here in Germany if you know about them - and i didn't) and also a replacement for the mechanic of my second 1520.

Next month I want to plot some HPGL-Files on the 1520 during the "Hobby & Electronic" fair in Stuttgart (as "hardcopy" for the Graphic Booster Plot Programm http://www.c128.net/infos/gb128info.htm http://www.c128.net/album/he2004/Cimg3553.jpg). I hope the printer will withstand this torture.

regards WTE

[airship]

I wouldn't torture it at all if I were you - the 1520 is a delicate little flower.

I've got mine apart. Without pens it was hard to tell, but I finally realized the pen solenoid wasn't working. After taking it off and playing with it, I think I know why - the shaft has become a permanent magnet! Now, I'm not much of an electronics expert, but I'm pretty sure that's not supposed to happen...

BTW, cutting down a ballpoint pen to just about the right length and wrapping it with tape until it's just about the right diameter doesn't work. They must have to be a mite more precise than that!

[hydrophilic]

BTW, cutting down a ballpoint pen to just about the right length and wrapping it with tape until it's just about the right diameter doesn't work. They must have to be a mite more precise than that!

Nice to see some creativitiy even if it fails.  Maybe something more sturdy than tape would work?  Like aluminum foil, or some type of cast (plaster or epoxy)?

I'm just brainstorming so just remember: if it ain't broke don't fix it!

BTW, nice guide.  I don't own a 1520 plotter but I learned a lot and I'm sure real owners will appreciate all the links.

[airship]

The problem wasn't the girth, it was the length. The diameter isn't an issue as long as it holds the pen in the revolver slot pretty snugly so it doesn't fall out, and it doesn't rub as the revolver rotates. But the length is absolutely critical. The solenoid only taps the pen in and out a millimeter or two.

[wte]

Arrrrghhhh!

PARTS

The ALPS plotter mechanisms are very fragile, and the cheap plastic gears have a tendency to break. As stated above, B&C Computersisions claims to have replacement pen holders (the 'revolver' mechanism) for $1.95 each.

But Electronic Goldmine (http://www.goldmine-elec.com/) currently has the entire mechanism as a surplus part:

ALPS 4 Color Head Assembly - $1.49
htp://www.goldmine-elec-products.com/p ... ber=G15824

4 Color Pen Printhead by ALPS - $3.49
http://www.goldmine-elec-products.com/p ... mber=G2092

Electronic Firing Mechanism - $3.49
htp://www.goldmine-elec-products.com/p ... mber=G2093

I'd tried to buy 4 complete mechanic parts (because one if my 1520 has a defective gear). Made my order and that was the answer:

Please be advised that this order has been cancelled because we do not ship to EU countries due to the R.O.H.S law now in effect. Note that your credit card has not been charged.

Regards,
The Electronic Goldmine

R.O.H.S Argh! f... f... f... fast haette ich was gesagt :förbannad:

Is there anybody in outerspace who is willing to buy four complete mechanics and send it to "R.O.H.S.-Country" ?

Regards WTE

[Blacklord]

Arrrrghhhh!
Is there anybody in outerspace who is willing to buy four complete mechanics and send it to "R.O.H.S.-Country" ?

Regards WTE

"The RoHS Directive stands for "the restriction of the use of certain hazardous substances in electrical and electronic equipment".  This Directive bans the placing on the EU market of new electrical and electronic equipment containing more than agreed levels of lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyl (PBB) and polybrominated diphenyl ether (PBDE) flame retardants."

Bummer huh ?

Lance

[airship]

And, of course, everyone knows that the ALPS 1520 plotter mechanism is made of nothing BUT lead, cadmium, mercury, hexavalent chromium, and polybrominated biphenyl (PBB), all slathered with a thick coating of polybrominated diphenyl ether (PBDE) flame retardants.

It's almost as though the law was written to SPECIFICALLY prohibit the import of ALPS 1520 plotter mechanisms into the E.U. Makes you think, doesn't it? Can you say 'conspiracy'? :förvånad:

[airship]

It's interesting (at least to me) that the Sharp datasheet, for the LB1257 controller chip used to drive the two stepper motors in the 1520 says, "Especially suited for X-Y plotter driver (Meeting the requirements for Alps DPG plotter)". But apparently it's also good for driving LEDs, so you could use the 1520 controller board for a 'blinkenlights' display if you could figure out the programming sequences. Maybe it would be cool to just see what the lights would do when you send it a 'spirograph' plot. I've got a whole drawer full of LEDs, so maybe I'll try it this weekend.

The controller board is also small enough to use in a robot. The 1520 controller could be mated to a 12V battery to drive two stepper motors and a solenoid that could be remote controlled by 1520 plotter commands. You could just hook it up with a 20' serial cable (such things exist - they were used in schools along with peripheral switchboxes), but it would be cooler with a radio transmitter hacked into the C64's IEC serial line and a decoding receiver on the robot. With the pendown solenoid and a Flair pen, you could make a wicked cool drawing robot, though the drawing math would have to be adjusted.

[airship]

B&C Computervisions tells me that they are OUT of the black ink pens. However, they just confirmed my order for two rolls of paper and five sets of the color pens @$5/ea. We'll see how long it takes and whether the pens work when they show up. I'll report back in this thread. (BTW, their web site says 'limit 3' on the color pen sets, but since they were out of black and I begged they let me order five.) Their email response to my order says 'Please allow 2 weeks for delivery'.

I'll also report back when the four mechanisms I have coming from Electronic Goldmine show up.

[airship]

This guy says he has tubes of 4 'NOS' black pens for $5 + shipping. I'm emailing him about availability and will report back.

http://www.commodore64.allhell.com/

No luck. Here's his response:

Actually I just sold out of them. I do have some atari branded ones I would sell but i dont know if they are dried up or not and I dont want to open them. I could spare a couple tubes but the price is now $15 /tube.Sorry but they just arent available anywhere anymore.

[Golan Klinger]

http://www.commodore64.allhell.com/

That's KilrPilr (aka Leo LaFlamme). Geez, I must know everybody.

[airship]

You know, Golan, you COULD be saving me a LOT of research here if you'd just tell me about these guys in the first place.

[airship]

Who knew Commodore ever sold its own branded version of 1520 plotter paper? Three rolls per box. Aussie eBay auction # 260172371677 has a beat-up but complete box with a starting bid of AU99 cents:

[wte]

Who knew Commodore ever sold its own branded version of 1520 plotter paper? Three rolls per box. Aussie eBay auction # 260172371677 has a beat-up but complete box with a starting bid of AU99 cents...

I do! 'cause I own one. And my box looks a little bit better.

Is there anybody in outerspace who is willing to buy four complete mechanics and send it to "R.O.H.S.-Country" ?

No reply, no help? :gråta:

[airship]

wte, check your PMs. I sent you one shortly after you asked.

[airship]

Well, I've got my 1520 set up with the connector driving 9 LEDs instead of the plotter.

I've got 8 bars of a red 10-LED bargraph display hooked to the two sets of stepper motor coil drivers, and a big yellow LED driven by a 5v relay hanging off the pen solenoid driver.

I'd upload a video, but my webcam has chosen to take a dump. It seems to be fighting a battle with my WinTV card for video supremacy of my PC. Once I figure that out, I'll get one posted.

But it is REALLY cool to watch a plotting routine driving LEDs instead!

[wte]

wte, check your PMs. I sent you one shortly after you asked.

Ah, thanks. I didn't noticed (never looked to PM before). You've got a reply.
Edit: last given price of the pen set (4 colours): Euro 12.70 plus shipping costs [but I will check this]

[airship]

The stepper circuits fire so fast that the blinking is just a blur. The only fun stuff happens at transitions when the platen scrolls or the pen solenoid fires. Still, the patterns are interesting and it actually gives you some feeling for what's going on inside.

I'd love to build a permanent 'blinkenlights' display for my little 1520. I'm sure the driver circuits could handle a stepper motor and an LED on each line. I don't think I really need the relay for the pen solenoid line, but all of those driver transistors had me worried I might blow an LED. What do they cost now? A penny? Maybe I'll chance one.

What was most interesting to me is that by just jumpering the color sense switch (pins 1 & 2, brown & red) the 1520 driver board was perfectly convinced that it was plotting stuff. Not only that, I  parasitically took the supply voltage for all the LEDs from the same line.

[airship]

I've decided you'll have to settle for a camera phone photo:



The four lights on the left are for the platen motor, the four on the right for the head motor. The big yellow one is the pen solenoid.

Note the presence of actual PENS and PAPER ROLLS in the picture! B&C Computervisions ships FAST! The only indignity was having a package delivered that had the ATARI logo on it!!

The paper rolls are only about 2 in. in diameter, not 3, but for $3.95 you get two rolls and who can plot that much anyway?

They tested the pens (by writing on my invoice) and they do write. I don't know if they plot, because I haven't torn down my lights yet. As I said above, I suspect my pen solenoid is toast, anyway, so I'll probably have to wait until my new mechanisms get here from Electronic Goldmine.

EDIT: Not only is the solenoid shot, a closer inspection shows that not one but BOTH of my stepper motor gears (the tiny ones that slip directly on the motor's shaft) are split. That explains the ticking noises AND the platen's reluctance to turn under power. Hopefully I'll have some luck with the replacement mechanisms. The 'lemonade' side of all this is that I can strip this unit down for parts, which includes two good stepper motors (though obviously NOT gears to go with them). Another Edit: There was also a nice reed switch with nylon mounting bracket. The two steppers came out with the PC header connector board still attached. The reed switch is also attached to the PC board, as is the pen solenoid. If it all worked, this alone would make a super framework for a little robot. With very little work, the circuit board would even break down into separate halves; one for each stepper, one of which would have the reed switch and one the solenoid. Add in the screws, springs, gears, steel shafts, rubber roller, etc., and you've got a nice little grab bag of parts for just $4.

[wte]

Edit: last given price of the pen set (4 colours): Euro 12.70 plus shipping costs [but I will check this]

Yesterday night [european time zone] i posted a request to the email address mentioned on the MZ plotter page [http://www.sharpmz.org/first.htm]. Today I've got the answer (they are working on sundays! - It seems to be a very small business).

Original:

Sehr geehrter Herr Dr. ...,

wir fertigen diese Stifte in Deutschland seit einigen Jahren nach, vorwiegend für unser Kerngeschäft medizinisches Gerätezubehör.
Sie sind durch den Fertigungsstandort Deutschland und die überschaubaren Stückzahlen nicht gerade billig, qualitativ aber einwandfrei.
Ein Satz ( 4 Stifte ) kostet 16,90 Euro zzgl. Mwst. und Versand. ...  Hier würden wir 6,00 berechnen ( Maxibrief + Einschreiben )...

Mit freundlichem Gruß

Peter Laß

Christiane Laß
Versand med. Zubehörartikel
Falckstraße 24
D-25451 Quickborn
Phone: +49 (0) 4106 / 758 43
Fax: +49 (0) 4106 / 783 57

I've tried to translate it correspondingly:

We reproduce this pens in Germany since several years, predominantly for our core business medical equipment accessorys.
As manufactured in Germany and only in small lots they are not really cheap but the quality is faultlessly.
A set (4 pens) costs 16.90 Euro (netto) and additional 19% VAT [=> 20.11 EUR => ~ 28,78 US$] and shipping 6 EUR.

The actual price is much higher than the price mentioned on the MZ fan page!

I've also asked for a bargain for 10 pen sets but there is no.