Re: Tandon TM-100-1 electronics repair
On Thu, Apr 27, 2017 at 11:49 PM, Chuck Guzis via cctalk wrote: >> On Thu, 27 Apr 2017, Ethan Dicks via cctalk wrote: >> >>> Additionally, for a testing framework to poke signals through the >>> drive for debugging during the repair, what's a good platform? A >>> PC running MS-DOS? The TRS-80 Model 4 itself? Besides doing >>> directories, are there any good bits of software anyone can >>> recommend for exercising floppy drives on a sub-system-by-subsystem >>> basis? (move the heads, do a read, do a write...) > > > I'd still recommend Dave Dunfield's ImageDisk--it's got several good > functions--test RPM, Clean heads, check alignment, etc. > > Runs on MS-DOS and, AFAIK, even on the 5150. > > I'm actually a bit surprised that nobody's done a floppy exerciser for > the lowly Arduino. Easy enough--if you use the timer "capture" feature > on the AVR, you can even do simple disk read testing. KryoFlux has something like that. https://www.kryoflux.com/ has the details, but it is commercial. Warner
Re: Tandon TM-100-1 electronics repair
> On Thu, 27 Apr 2017, Ethan Dicks via cctalk wrote: > >> Additionally, for a testing framework to poke signals through the >> drive for debugging during the repair, what's a good platform? A >> PC running MS-DOS? The TRS-80 Model 4 itself? Besides doing >> directories, are there any good bits of software anyone can >> recommend for exercising floppy drives on a sub-system-by-subsystem >> basis? (move the heads, do a read, do a write...) I'd still recommend Dave Dunfield's ImageDisk--it's got several good functions--test RPM, Clean heads, check alignment, etc. Runs on MS-DOS and, AFAIK, even on the 5150. I'm actually a bit surprised that nobody's done a floppy exerciser for the lowly Arduino. Easy enough--if you use the timer "capture" feature on the AVR, you can even do simple disk read testing. --Chuck
Anyone driving from the Midwest to VCF_SE this weekend?
I am flying in and wondering if someone had any extra room coming home (for parts, not me). Jim -- Jim Brain br...@jbrain.com www.jbrain.com
Re: RA82 HDA
Heh no. I’m going to ship it. It’s just the HDA assembly so it’s a lot more compact than the entire drive. Still it’s a heavy mutha :-) Kirk > On Apr 27, 2017, at 12:08 PM, Bill Gunshannon > wrote: > > Did he come with a liftgate pickup truck? :-) > > bill > > > From: cctalk [cctalk-boun...@classiccmp.org] on behalf of Kirk Davis via > cctalk [cctalk@classiccmp.org] > Sent: Thursday, April 27, 2017 2:49 PM > To: shad; General Discussion: On-Topic and Off-Topic Posts > Subject: Re: RA82 HDA > > San Jose, California. Someone has already nabbed it. > > Kirk > >> On Apr 27, 2017, at 11:03 AM, shad via cctalk >> wrote: >> >> Hello, >> where are you located? >> If you are in EU, I'm interested. >> >> Thanks >> Andrea >
Re: Tandon TM-100-1 electronics repair
On Thu, 27 Apr 2017, Ethan Dicks via cctalk wrote: Additionally, for a testing framework to poke signals through the drive for debugging during the repair, what's a good platform? A PC running MS-DOS? The TRS-80 Model 4 itself? Besides doing directories, are there any good bits of software anyone can recommend for exercising floppy drives on a sub-system-by-subsystem basis? (move the heads, do a read, do a write...) You should check out a couple of disk utility programs for the Model 4: Super Utility 4/4P http://tim-mann.org/trs80/su4a.zip (CMD version) https://fjkraan.home.xs4all.nl/comp/trs80-4p/dmkeilImages/util/97-0005.ace (bootable version) http://tim-mann.org/trs80/doc/su4man.pdf Hyperzap 3.2C https://fjkraan.home.xs4all.nl/97-0002.ace If you hook up a working drive to boot from, one of those should help to exercise/exorcise the bad drive. :-) Mike Loewen mloe...@cpumagic.scol.pa.us Old Technology http://q7.neurotica.com/Oldtech/
Re: Tandon TM-100-1 electronics repair
On Thu, Apr 27, 2017 at 4:43 PM, Fred Cisin via cctalk wrote: > On Thu, 27 Apr 2017, Ethan Dicks via cctalk wrote: >> >> It's not impossible to find another TM-100-1 or replace it with a >> TM-100-2 > > Actually, the IBM 5150 PC originally (August 1981) mostly came with TM100-1. > It wasn't until about nine months later, when IBM released PC-DOS 1.10 (May, > 1982, which supported double sided drives) that they added TM100-2 > availability. Ah. I had forgotten that detail. I only ever worked machines with double-sided drives. > Why not use the TM100-2? It will work for any of the single sided use, and > some versions of the operating systems supported double sided drives. > (On the Tandy version of LDOS, double sided support was undocumented, > because Tandy didn't sell a double sided drive, until the model 4D?) I know it will work. > Remember that the PC uses all drives jumpered as if they were :1/DS1/B: Right. I well remember how to jumper drive selects. > Radio Shack used an "unused" pin of the interface for drive :3/DS3/D:, > Unfortunately, that was the pin that was "reserved" for side select! > That poses a problem for model 1 (with four drives on one cable), but not > for III, 4, nor 4P Yes. I was reading about that the other day. I don't have any 4-drive units, just multiple dual-drive units. > If you have a model 1 drive that has the modification for drive select using > the side select signal, don't use it if you use any double sided drives in > the machine, or clip that wire on the drive. Good to keep in mind. I borrowed a half-height "Bachelor" FD-104 from a Model 1 for drive/controller testing. I cannot find docs for it, and barely a mention, even in TheRef. There is one jumper block by the 34-pin edge connector - marked D.S. / 0 / (1) / 2 / 3 / MX. (the '1' is damaged/missing because of a PCB via). It seems the first jumper is likely to be single/double-sided (there are 2 heads), then 4 drive selects, then the MX one-drive-only-select jumper. > You can use "half-height" drives in a model 3 or 4. Yes but at the moment, I only have one half-height 40-track drive, that Bachelor FD-104. My only loose drives are 80-track HD units. -ethan
Re: Tandon TM-100-1 electronics repair
On Thu, Apr 27, 2017 at 1:58 PM, Tony Duell wrote: > On Thu, Apr 27, 2017 at 6:42 PM, Ethan Dicks via cctalk >> (diagnosing and repairing a) TM-100-1 floppy drive... > Floppy drives of that vintage consist of a number of almost independant > systems (there's a common enable/drive select but that's about it). > It looks like a problem in the read chain, but is it? If the spindle was > turning at the wrong speed I think it would fail to read. Yes. I did consider the spindle speed, but I'm reasonably certain it's good. > So I would check each subsection of the drive, just in case it's not > the obvious one. Well, yes. I'm really just asking about known weaknesses as a starting point. > In the case of the read amplifier, you could start with a differential- > input 'scope on the pins used for head alignment (reading a normal > disk). If there's a good signal there the head select diodes (AFAIK > these are present even on the single-sided drive) and first amplifier > IC are OK. If not, then debug that part. Right. > I don't know of any obvious common failures, and anyway > murphy's law will ensure that your drive has something odd failed :-) Perhaps. The last failure with this unit had the most obvious cause. I literally tested one component and it was exactly that part that had failed. >> Additionally, for a testing framework... > There are/were drive exercisers but no idea where you'd find one now. > If you were nearer to me, you could use mine Right. I don't have a drive exerciser (and I live in the States) so I didn't figure that was an easily achievable path. I'm figuring on having to use a live machine to make the drive dance and I don't fancy writing my own code on top of it all. Rather than go to that extent, I'm more likely to toss the drive on the "to be fixed someday" pile and get to it (much) later. > You need a 'scope to debug the read amplifier of course (that > applies even if you have a drive exerciser). Yes. Of course I have a scope. At least one. > Do check the spindle speed. Often there is a strobe disk on the > spindle pulley in these drives There is. It works. > But also check ('scope) that you are getting 5 index pulses > per second, just in case the darn thing is running at half speed or > something. Worth verifying, but there's a visual difference between 300 RPM and 150 RPM (plus they sound different). -ethan
Re: test, please ignore
(Waits for Jay's next email "This has been a test of the new auto banning system. Thank you.") Original message From: Alexandre Souza via cctalk Date: 4/27/17 1:58 PM (GMT-06:00) To: "General Discussion: On-Topic and Off-Topic Posts" , Jay West Subject: Re: test, please ignore This is a test, designed to provoke an emotional response Enviado do meu Tele-Movel On Apr 26, 2017 9:39 PM, "Jay West via cctalk" wrote: > Don't need a response, please ignore. > > > > J > >
Air Force Issues Challenge to “Hack the Air Force” 04/26/2017 04:10 PM CDT --
IMMEDIATE RELEASE No. NR-145-17 April 26, 2017 Air Force Issues Challenge to “Hack the Air Force” The Air Force is inviting vetted computer security specialists from across the U.S. and select partner nations to do their best to hack some of its key public websites. The initiative is part of the Cyber Secure campaign sponsored by the Air Force’s Chief Information Office as a measure to further operationalize the domain and leverage talent from both within and outside the Department of Defense. The event expands on the DoD ‘Hack the Pentagon’ bug bounty program by broadening the participation pool from U.S. citizens to include “white hat” hackers from the United Kingdom, Canada, Australia and New Zealand. “This outside approach--drawing on the talent and expertise of our citizens and partner-nation citizens--in identifying our security vulnerabilities will help bolster our cybersecurity. We already aggressively conduct exercises and 'red team' our public facing and critical websites. But this next step throws open the doors and brings additional talent onto our cyber team,” said Air Force Chief of Staff Gen. David Goldfein. White hat hacking and crowdsourced security concepts are industry standards that are used by small businesses and large corporations alike to better secure their networks against malicious attacks. Bug bounty programs offer paid bounties for all legitimate vulnerabilities reported. “This is the first time the AF has opened up our networks to such a broad scrutiny,” said Air Force Chief Information Security Officer Peter Kim. “ We have malicious hackers trying to get into our systems every day. It will be nice to have friendly hackers taking a shot and, most importantly, showing us how to improve our cybersecurity and defense posture. The additional participation from our partner nations greatly widens the variety of experience available to find additional unique vulnerabilities.” Kim made the announcement at a kick-off event held at the headquarters of HackerOne, the contracted security consulting firm running the contest. "The whole idea of 'security through obscurity' is completely backwards. We need to understand where our weaknesses are in order to fix them, and there is no better way than to open it up to the global hacker community," said Chris Lynch of the Defense Digital Service (DDS), an organization comprised of industry experts incorporating critical private sector experience across numerous digital challenges. The competition for technical talent in both the public and private sectors is fiercer than it has ever been according to Kim. The Air Force must compete with companies like Facebook and Google for the best and brightest, particularly in the science, technology, engineering, and math fields. Keen to leverage private sector talent, the Air Force partnered with DDS to launch the Air Force Digital Service team in January 2017, affording a creative solution that turns that competition for talent into a partnership. In fact, Acting Secretary of the Air Force Lisa S. Disbrow and Gen. Goldfein visited the Defense Digital Service and Air Force Digital Service in early April to discuss a variety of initiatives the Air Force can benefit from. “We're mobilizing the best talent from across the nation and among partner nations to help strengthen the Air Force's cyber defenses. It's an exciting venture, one that will make us better, and one that focuses an incredible pool of capabilities toward keeping our Air Force sites secure," said Acting Secretary Disbrow. The DoD’s ‘Hack the Pentagon’ initiative was launched by the Defense Digital Service in April 2016 as the first bug bounty program employed by the federal government. More than 1,400 hackers registered to participate in the program. Nearly 200 reports were received within the first six hours of the program’s launch, and $75,000 in total bounties was paid out to participating hackers. Registration for the ‘Hack the Air Force’ event opens on May 15th on the _HackerOne_ (http://links.govdelivery.com/track?type=click&enid =ZWFzPTEmbWFpbGluZ2lkPTIwMTcwNDI3LjcyNzk2MTYxJm1lc3NhZ2VpZD1NREItUFJELUJVTC0yMDE3MDQyNy43M jc5NjE2MSZkYXRhYmFzZWlkPTEwMDEmc2VyaWFsPTE3NDEwNDE5JmVtYWlsaWQ9Y291cnlob3VzZ UBhb2wuY29tJnVzZXJpZD1jb3VyeWhvdXNlQGFvbC5jb20mZmw9JmV4dHJhPU11bHRpdmFyaWF0Z UlkPSYmJg==&&&101&&&https://www.hackerone.com/?source=GovDelivery) website. The contest opens on May 30th and ends on June 23rd. Military members and government civilians are not eligible for compensation, but can participate on-duty with supervisor approval. Updates from the U.S. Department of Defense
Re: Tandon TM-100-1 electronics repair
On Thu, 27 Apr 2017, Ethan Dicks via cctalk wrote: It's not impossible to find another TM-100-1 or replace it with a TM-100-2 (more common, owing to its appearance in the IBM 5150 PC), but I'd like to just repair this one and get back to TRS-80 hacking. Actually, the IBM 5150 PC originally (August 1981) mostly came with TM100-1. It wasn't until about nine months later, when IBM released PC-DOS 1.10 (May, 1982, which supported double sided drives) that they added TM100-2 availability. Why not use the TM100-2? It will work for any of the single sided use, and some versions of the operating systems supported double sided drives. (On the Tandy version of LDOS, double sided support was undocumented, because Tandy didn't sell a double sided drive, until the model 4D?) Remember that the PC uses all drives jumpered as if they were :1/DS1/B: Radio Shack used an "unused" pin of the interface for drive :3/DS3/D:, Unfortunately, that was the pin that was "reserved" for side select! That poses a problem for model 1 (with four drives on one cable), but not for III, 4, nor 4P If you have a model 1 drive that has the modification for drive select using the side select signal, don't use it if you use any double sided drives in the machine, or clip that wire on the drive. You can use "half-height" drives in a model 3 or 4.
Re: IBM 3420 x2 + 3803 for sale
I am interested in your tape drives if you still have them.. Can you send photos of all components? Victor Presher 214-905-4447
Re: Tandon TM-100-1 electronics repair
On 04/27/2017 10:42 AM, Ethan Dicks via cctalk wrote: > It's not impossible to find another TM-100-1 or replace it with a > TM-100-2 (more common, owing to its appearance in the IBM 5150 PC), > but I'd like to just repair this one and get back to TRS-80 hacking. The issue with Jugi's artistry is that there isn't a single version of the PCB for the TM-100. I have drives with 3- 4- and 6-wire steppers on them, all taking different PCBs. But a TM-100 is a very simple-minded device. You can easily check its basic mechanical operation off the system by grounding various signal lines (all are active-low). So you can ground the motor line to make sure that the motor spins; you can ground the drive select to see if the LED illuminates. With the drive select operating, you cna use the STEP and DIRECTION lines to move the head carriage; you can check the operation of the track zero sensor. Checking the read-write channel is a bit more challenging and a 'scope can be very useful. For lack of anything else, if you've got a PC with a floppy controller, you can use Dave Dunfield's ImageDisk utility to perform simple checks. He includes an RPM tester, though if the drive still has the strobe disk attached to the spindle flywheel, a simple line-operated neon lamp can do the same. --Chuck
RE: RA82 HDA
Did he come with a liftgate pickup truck? :-) bill From: cctalk [cctalk-boun...@classiccmp.org] on behalf of Kirk Davis via cctalk [cctalk@classiccmp.org] Sent: Thursday, April 27, 2017 2:49 PM To: shad; General Discussion: On-Topic and Off-Topic Posts Subject: Re: RA82 HDA San Jose, California. Someone has already nabbed it. Kirk > On Apr 27, 2017, at 11:03 AM, shad via cctalk > wrote: > > Hello, > where are you located? > If you are in EU, I'm interested. > > Thanks > Andrea
Re: test, please ignore
This is a test, designed to provoke an emotional response Enviado do meu Tele-Movel On Apr 26, 2017 9:39 PM, "Jay West via cctalk" wrote: > Don't need a response, please ignore. > > > > J > >
Re: RA82 HDA
San Jose, California. Someone has already nabbed it. Kirk > On Apr 27, 2017, at 11:03 AM, shad via cctalk > wrote: > > Hello, > where are you located? > If you are in EU, I'm interested. > > Thanks > Andrea
Re: RA82 HDA
Hello, where are you located? If you are in EU, I'm interested. Thanks Andrea
Re: Tandon TM-100-1 electronics repair
On Thu, Apr 27, 2017 at 6:42 PM, Ethan Dicks via cctalk wrote: > Hi, All, > > I'm cleaning/refurbing a TRS-80 Model 4 I picked up at VCFe that was > in dirty-but-mostly-working shape. I've completely dismantled, > cleaned and reassembled the keyboard, I fixed the bad cable to the > floppy controller, I cleaned and lubed the TM-100-1 floppy drive, and > had it all nice and working, then I bumped the power strip it was > plugged into and the momentary surge took out the electronics on the > floppy drive. I swapped it out with another TM-100-1 unit (borrowed > from a Model 1) and it's booting again, but when using this toasted > drive as :1, I get either an ERROR 3 or ERROR 4 from TRSDOS 1.3 (my > primary testing disk for the moment). The drive still seeks and spins > but it won't read disks that it used to read before the power hit. > > I also have an original NEWDOS/80 disk and a copied MULTIDOS disk. I > have not yet fixed up a PC with a 40-track 5.25" drive for making > fresh disks, but it's on the list of solution paths. > > I have the TM-100 service manual PDF (which includes schematics), so > it shouldn't be difficult to work through the functional subsystems of > the drive electronics. My question is are there any specific issues > with the parts on the TM-100 PCB to look for? There are a handful of > reasonably common ICs, and dozens of discrete components. Of course I > can trace through each section looking for where the results are > unexpected, but for such a common thing as a TM-100, perhaps there are > known pain points and perhaps someone here has repaired a few and > could highlight what parts might be "fragile". Floppy drives of that vintage consist of a number of almost independant systems (there's a common enable/drive select but that's about it). It looks like a problem in the read chain, but is it? If the spindle was turning at the wrong speed I think it would fail to read. So I would check each subsection of the drive, just in case it's not the obvious one. In the case of the read amplifier, you could start with a differential- input 'scope on the pins used for head alignment (reading a normal disk). If there's a good signal there the head select diodes (AFAIK these are present even on the single-sided drive) and first amplifier IC are OK. If not, then debug that part. I don't know of any obvious common failures, and anyway murphy's law will ensure that your drive has something odd failed :-) Stock fault lists are useful if you have many indentical units to repair, you might get 90% of them off the bench quickly but fairly useless for one-off jobs. > > Additionally, for a testing framework to poke signals through the > drive for debugging during the repair, what's a good platform? A PC > running MS-DOS? The TRS-80 Model 4 itself? Besides doing > directories, are there any good bits of software anyone can recommend > for exercising floppy drives on a sub-system-by-subsystem basis? > (move the heads, do a read, do a write...) There are/were drive exercisers but no idea where you'd find one now. If you were nearer to me, you could use mine More seriously, the signals involved are fairly slow speed. Before I had a drive exerciser, I linked the important drive inputs (select, motor on, step, direction, etc) to a PC parallel port and wrote a short program (I think in Turbo Pascal, but it was a long time ago) to turn the motor on, step the heads around, etc. I think I monitored some of the drive outputs using the printer port input lines too, but a logic probe is all you really need to check index, track 0, etc. You need a 'scope to debug the read amplifier of course (that applies even if you have a drive exerciser). Do check the spindle speed. Often there is a strobe disk on the spindle pulley in these drives (if it's missing, I am sure you can get an image of it somewhere, print it, cut it out and stick it on the pulley). But also check ('scope) that you are getting 5 index pulses per second, just in case the darn thing is running at half speed or something. -tony
Re: Help identifying this old terminal
On Wed, Apr 26, 2017 at 3:24 PM, Syd Bolton via cctalk wrote: > Anybody recognize what kind of terminal this is? If you think you attached a photo, you did not. This list filters out attachments. Send a link to a photo. -ethan
Tandon TM-100-1 electronics repair
Hi, All, I'm cleaning/refurbing a TRS-80 Model 4 I picked up at VCFe that was in dirty-but-mostly-working shape. I've completely dismantled, cleaned and reassembled the keyboard, I fixed the bad cable to the floppy controller, I cleaned and lubed the TM-100-1 floppy drive, and had it all nice and working, then I bumped the power strip it was plugged into and the momentary surge took out the electronics on the floppy drive. I swapped it out with another TM-100-1 unit (borrowed from a Model 1) and it's booting again, but when using this toasted drive as :1, I get either an ERROR 3 or ERROR 4 from TRSDOS 1.3 (my primary testing disk for the moment). The drive still seeks and spins but it won't read disks that it used to read before the power hit. I also have an original NEWDOS/80 disk and a copied MULTIDOS disk. I have not yet fixed up a PC with a 40-track 5.25" drive for making fresh disks, but it's on the list of solution paths. I have the TM-100 service manual PDF (which includes schematics), so it shouldn't be difficult to work through the functional subsystems of the drive electronics. My question is are there any specific issues with the parts on the TM-100 PCB to look for? There are a handful of reasonably common ICs, and dozens of discrete components. Of course I can trace through each section looking for where the results are unexpected, but for such a common thing as a TM-100, perhaps there are known pain points and perhaps someone here has repaired a few and could highlight what parts might be "fragile". Additionally, for a testing framework to poke signals through the drive for debugging during the repair, what's a good platform? A PC running MS-DOS? The TRS-80 Model 4 itself? Besides doing directories, are there any good bits of software anyone can recommend for exercising floppy drives on a sub-system-by-subsystem basis? (move the heads, do a read, do a write...) I expect like the last repair (shorted tantalum filter cap), this repair is going to be a small number of components. Parts of the drive are known to work - the motor turns on and off when it should, and it does seek back to track zero when manually moved off of track zero prior to doing a DIR :1 or when booting it as :0. At first glance, something appears to be toasted in the read electronics. It's not impossible to find another TM-100-1 or replace it with a TM-100-2 (more common, owing to its appearance in the IBM 5150 PC), but I'd like to just repair this one and get back to TRS-80 hacking. Thanks for any tips or pointers. -ethan
Re: test, please ignore
LOL A+ thread would read again -- Anders Nelson +1 (517) 775-6129 www.erogear.com On Thu, Apr 27, 2017 at 1:02 PM, Alfred M. Szmidt via cctalk < cctalk@classiccmp.org> wrote: > This isn't a response, do not ignore. >
Re: test, please ignore
This isn't a response, do not ignore.
Re: ISO Matrox Multibus SX-900 graphics card manual
On Thu, Apr 27, 2017 at 8:49 AM, Glen Slick wrote: > > If anyone is interested in images of the Q-Bus version QG-640 I posted > a scan of one here, along with binary images of the firmware: > > https://drive.google.com/open?id=0B8Vwo-hnhVM5dUhOYnZqY3JUM3M > Sorry for sidetracking this thread further. I meant to post this link to the folder, not an individual file. https://drive.google.com/open?id=0B8Vwo-hnhVM5X3puYVZ2U0E5NFU
Re: ISO Matrox Multibus SX-900 graphics card manual
On Thu, Apr 27, 2017 at 12:37 AM, r.stricklin via cctalk wrote: > > On Apr 26, 2017, at 6:01 PM, Glen Slick via cctech wrote: > >> While on the topic of Matrox graphics boards from around the same time >> frame, does anyone know of any Matrox boards that use an NS32016 CPU >> other than the QG-640? > > The Matrox PG-640. Same graphics accelerator, but for PC compatibles. I just > happened to have one sitting out on the counter. I checked it and it > definitely has an NS32016 on it. > Thank you. Mystery solved. The board in question does appear to be a match for the bottom board of the Matrox PG-640 board set shown in the photos of this eBay listing: http://www.ebay.com/itm/311599569320 If anyone is interested in images of the Q-Bus version QG-640 I posted a scan of one here, along with binary images of the firmware: https://drive.google.com/open?id=0B8Vwo-hnhVM5dUhOYnZqY3JUM3M Back on topic, hope someone can provide Al with a copy of the Matrox Multibus SX-900 graphics card manual.
Re: ISO Matrox Multibus SX-900 graphics card manual
On Apr 26, 2017, at 6:01 PM, Glen Slick via cctech wrote: > While on the topic of Matrox graphics boards from around the same time > frame, does anyone know of any Matrox boards that use an NS32016 CPU > other than the QG-640? The Matrox PG-640. Same graphics accelerator, but for PC compatibles. I just happened to have one sitting out on the counter. I checked it and it definitely has an NS32016 on it. The PG-640 is a dual-width 8-bit ISA card (instead of QBus for the QG-640). It's supposed to be compatible with the IBM PGC, but presumably only if your software behaves and doesn't try to program the 8086 on the PGC directly. My experience with the supposedly-PGC-compatible Vermont Microsystems Image Manager 1024 is that it is compatible (AutoCAD), except when it isn't (Generic CADD). I haven't actually tried to use the PG-640 yet so I can't say more about this. The PG-640 is supposed to be faster than the PGC, too. Perhaps it is, except when it isn't. ok bear. -- until further notice