Myarc cards for sale/repair tips

[+InsaneMultitasker]

2 hours ago, GDMike said:

nd left the cover off the Geneve

I've mentioned this in the past:  if you remove the clamshell from the Geneve and later tug downward on the monitor, keyboard, joystick, or mouse cable there is a chance you will tilt/lift the front end of Geneve card in its PEB slot, possibly shorting out the Geneve and other peripheral cards.  Even the PEB cover and the foam on the underside of the cover may not be enough to keep the card from shifting.  

 

I tell you this so you are informed and can take precautions with your cabling while you do your best to keep the card cool. 

 

[+dhe]

Bump for Ricky.

 

Hi Ricky,

   Did you get any further with PFM Geneve?

[RickyDean]

4 hours ago, dhe said:

Bump for Ricky.

 

Hi Ricky,

   Did you get any further with PFM Geneve?

No, been waiting for the insane one to get his thoughts together, life takes precedent over hobby. Been plenty to keep me occupied too.

[+InsaneMultitasker]

I moved my PFM+ Geneve to the workbench so maybe sometime this week or coming weekend I will have time to dig into your questions. 

 

[globeron]

 

https://atariage.com/forums/topic/309626-general-upscaler-thread/?do=findComment&comment=4880734

 

Trying my luck to see if someone in the general upscaler forum knows what the issue can be. Oe can it still be a Geneve 9640 issue because the Hz seems to keep changing between 59.x and 60.x see video.

Edited August 8, 2021 by globeron

[globeron]

On 8/8/2021 at 9:22 PM, globeron said:

 

https://atariage.com/forums/topic/309626-general-upscaler-thread/?do=findComment&comment=4880734

 

Trying my luck to see if someone in the general upscaler forum knows what the issue can be. Oe can it still be a Geneve 9640 issue because the Hz seems to keep changing between 59.x and 60.x see video.

 

After troubleshooting/swapping HDMI cables, monitor, etc. (and having suddenly a stable signal somehow). We finally found the issue when my kid turned on his PC  which has a 5m USB cable  (and another 5m USB cable extender) connected to a USB to DB9 and then DB9 to DB25 and to the DB25 of RS232 interface card in the Geneve 9640, which apparently interferes the signal via the RS232 card/PEB box to the Geneve card and interferes with the video signal of the Geneve itself I guess? (or it is external interference of the USB cable to the other cables) or the OSSC device ?  or Monitor?    No clue, but now the video-signal is stable and can use the Geneve 9640 normally.   

 

Question:  in MY ART  when changing different graphic modes (with Enter) between 16 and 256 colors, it is normal that the monitor need to sync. the signal again, correct? 

 

 

 

 

[Brufnus]

On 9/18/2018 at 12:51 AM, mizapf said:

 

It is definitely on my todo list, just to remind you.

 

(However, I also plan that my boot ROM has some Swan on the title screen, but maybe much smaller. I don't like boot EPROMs without the Swan. ? )

I agree! I miss the Swan, too... ;-(

[+InsaneMultitasker]

Spending some time trying to repair a Geneve today and the ol' bird is cantankerous at best.  Check out them stripes...

 

[+dhe]

Tim breaks through to second level on memex test!

[+InsaneMultitasker]

21 hours ago, dhe said:

Tim breaks through to second level on memex test!

The ol' bird won level 2.  Today I returned the Geneve the shelf to contemplate next steps for a future bout.  The random, hard to reproduce, intermittent connection failure is my least favorite problem to troubleshoot.

[+InsaneMultitasker]

Today I resurrected a SCSI revision "G" card. The card had been modified to take power directly from a PC power supply via a molex connector; I didn't want this particular setup any longer, so I replaced the power circuit with a DC-to-DC converter and proper caps.  Everything checked out OK but when placed in my PEB system, it caused lockups, other cards stayed activated during powerup, and other 'fun' problems.  Not knowing for certain if my mod caused the problem, I reverted to a 7805 w/caps; unfortunately, the same issue was present.   I didn't have any HCT244 chips laying around but I did have LS245s, so I replaced the LS245 and now the card seems to be functioning.  A part of me wants to try the DC-to-DC converter approach once more, another part of me wants to leave well enough along.  I will probably put this card up for sale if it continues to perform as expected. 

[+OLD CS1]

21 minutes ago, InsaneMultitasker said:

Today I resurrected a SCSI revision "G" card.

Is there a fix on these cards to make SCS0 work?  I have to use SCS1.

[+InsaneMultitasker]

34 minutes ago, OLD CS1 said:

Is there a fix on these cards to make SCS0 work?  I have to use SCS1.

If you mean a DSR modification to pair SCSI ID0 with SCS0, SCSI ID1 with SCS1,...SCSI ID6 with SCS6., then no, nothing that I am aware of.  Keep in mind that most DSRs avoid unit #0, thus for the SCSI card, SCS1 pairs to SCSI ID0 and so on.    Modifying the DSR could be relatively simple if unit 0 isn't used internally for other purposes.

[+OLD CS1]

42 minutes ago, InsaneMultitasker said:

Keep in mind that most DSRs avoid unit #0, thus for the SCSI card, SCS1 pairs to SCSI ID0 and so on.

I have to double-check, but I am pretty certain I have my SCSI device set for ID1.  Will report back later.

[+InsaneMultitasker]

24 minutes ago, OLD CS1 said:

I have to double-check, but I am pretty certain I have my SCSI device set for ID1.  Will report back later.

If so, it should respond to SCS2.

[+InsaneMultitasker]

Does anyone here have a GenMod Geneve at their disposal?  I would like to confirm whether or not the two GALs on the GenMod daughterboard (affixed to the back side of the Geneve) are socketed or soldered directly to the daughterboard.

 

The Genmod I am attempting to repair is socketed.  Unfortunately, the larger chip no longer has its legs/leads;  I suspect that its leads were intentionally shortened before installing on the daughterboard, most likely due to a previous repair attempt.

 

Some of the wires routed to the daughterboard were poorly soldered, so I am also assessing whether to attempt a complete removal and re-installation of the board or wire directly to the chip (bypassing the board).

 

We have good installation documentation but no way to produce/program the GALs as the info was never released.

 

[+InsaneMultitasker]

This weekend I unsoldered the genmod board from the Geneve, replaced the socket for the smaller GAL and soldered the larger GAL directly to the daughterboard.  All wired connections were cleaned up and confirmed and I touched up the gate array connections.  The major chips were replaced with functioning chips from my spare card (and the genmod Geneve's chips were tested in my spare for cross-validation) for test purposes.

 

Unfortunately, even after the cleanup and repairs, the Geneve would not recognize the 32K static RAM expansion and was exhibiting errors in the other memory pages. The gate array signal for the expansion RAM was tied to the genmod board, with proper continuity and no shorts that I could detect.  If the addressing was faulty, I would expect more than 4 pages to fail (in the same row or different columns), so I suspect the GAL is malfunctioning and can no longer access the expansion ram pages.    

 

Following discussion of the situation with the card's owner, I removed the genmod modification and turned the card back into a standard Geneve.  The card seems to be working and so far no memory errors or sporadic lockups.  I was quite torn over removing the genmod since not many of these devices are in working order, still, a working standard Geneve is better than a non-functioning genmod.  This week I'll do some burn-in testing together with other peripheral cards, before I return everything to the owner.

On 9/19/2021 at 1:08 PM, InsaneMultitasker said:

I suspect that its leads were intentionally shortened before installing on the daughterboard, most likely due to a previous repair attempt.

Update: the legs were intentionally clipped for clearance reasons between the genmod board and the surface of the back side of the Geneve.

[+InsaneMultitasker]

I was looking for a few parts today and I came across my old Allen-Bradley mug.   I thought I lost this small gem years ago when I moved!

 

         

[RickyDean]

17 hours ago, InsaneMultitasker said:

I was looking for a few parts today and I came across my old Allen-Bradley mug.   I thought I lost this small gem years ago when I moved!

 

         

Sheer awesomeness.

[+InsaneMultitasker]

I did some hard drive recovery work this week and learned a few things in the process:

 

1) MDM5 will let you format one cylinder.  This was very helpful, because the drive's first cylinder was not readable nor could I write to any individual sectors to the first cylinder.  After the format completed, I searched for "DIR" sectors and was able to access some of the folders and files, including ones the person wanted retrieved. 

2) While seeking through sectors manually, the Directory Descriptor Records were typically 8 sectors apart as expected for this size drive, but sometimes the gap was 6 sectors. This was very strange and did not follow the expected layout; it then occurred to me that the drive had been formatted with CFORM at 34 sectors/track. I adjusted sector 0 parameters and the DDRs returned to consistent 8-sector boundaries.  

3) I wrote a short program to copy sectors from the drive to a platter to reconstruct the image; unfortunately, there were more 'bad' sectors than good sectors on this drive

4) MDM5 is a pain to load if it exists on the bad hard drive, especially if one or more files are corrupted or missing.  I modified a set of MDM files to load from TIPI.MDM5. including the hard drive format program path (which is NOT set by the configuration option).   (This also works on the Geneve with ROMPAGE).  I successfully formatted the bad hard drive (after data retrieval) and returned to MDM5 successfully.  I suppose I could have used a TIPI DSKx. device but I wanted to always have the program accessible between systems for future HFDC testing/repair work.

 

If I have time this weekend, I will experiment formatting only the first head of the first cylinder. This would in theory preserve any directory/file pointers after sector 0x40 if there was ever a time to use this recovery process in the future.

[Restricted-Access]

On 11/2/2018 at 3:44 PM, InsaneMultitasker said:

I had a chance to take Heatwave offline this afternoon. I have temporarily swapped the Heatwave BBS Geneve with this newly updated card. I'll let it run for a few days to see how well it operates. I hope to find time to refresh the BBS card while it is out of service.

 

On a related note: although the Myarc cases look like plastic they are conductive. With the test leads in close proximity, I registered 1.5K; at a distance of 1 inch it was aproximately 3.4K. I suspect case composition varies. A few of the dc-to-dc converter leads needed to be clipped to avoid contact.

I'm sorry... I'm just reading this thread for the first time, and I don't know if this was addressed a few pages from now, but did you check the conductivity on the "outside" of the Myarc shells?  The inside is coated with a material to reduce RF interference.  Although clipping the leads so they don't contact the shell is a good idea, you could also insert a thin, hard sheet of plastic (it would need to be REALLY thin, and not soft enough to be scratched through) to insulate against the conductive coating.  Also, if you are not concerned about RF bleed... you could use some steel wool to strip that coating off!  In any case, it IS a plastic shell... it's just a conductive coating inside to block RF signals. ?

[Restricted-Access]

On 1/30/2021 at 7:07 PM, arcadeshopper said:

I have a genmod Geneve I picked up from bill in az and it has this loose cap right below the orange bodge wire.. I assume I need to put it back in there just confirming

Sent from my LM-V600 using Tapatalk
 

Is that capacitor next to the gate array & resistor pack, blown?  It looks like I can see the inside of it!

[Restricted-Access]

O-K... I have been reading all 22 pages of this thread, and it has taken me HOURS to get through all of it: There's a LOT here!

 

I had a couple of problems with my Geneve... over 30 years ago (give or take a few years).  I don't remember who I talked to, but I believe it was Don Walden.  I also don't remember the issue anymore, but I remember what ultimately fixed it (Tim, you may know or have heard about this - hopefully, Don made notes, since I can't remember what the problem was... I think it may have had something to do with the clock/date).

 

Anyway... Don was asking me to check the resistor packs (there's 4 of them: three 10-pin, one 6-pin).  One of the things I noticed, was one of the longer resistor packs... had a hairline crack in it!  It was barely perceptible.  In fact, you could only see it... if you flexed the MB slightly, and then you would see the split in the resistor pack (talk about your intermittent problems you can't see).  The best solution to this problem, is to remove the resistor pack (I did it, by using nippy cutters... and splitting the resistor pack, de-soldering & removing each segment, one-at-a-time), and solder-in a machined inline socket, and insert a new resistor pack.  I believe they were all 10K, and he had me replace them with 1K resistor packs.

 

That didn't work.  I think it made things worse, but I'm not sure... it's been too long.  Either he told me to try a slightly higher value (which is "probably" what happened), or I suggested it... but I went and bought another set of resistor packs, all 2.2K.  THAT did the trick!  I really don't remember the original problem (I'm sure that original, cracked resistor pack didn't help)... but I never had any problems after I replaced them all (incidentally, they didn't have any 6-pin 2.2K resistor packs... so I bought four 10-pin, and I simply cut-off the last four pins of one of the 10-pin resistor packs - yes, you can do that, and assuming you get a clean cut like I did, it will work just fine: NO LIQUID, OR SMOKE, will leak out)!

 

I don't know what the schematics say what the value of those resistor packs are "supposed to be"... but working with Don to solve the problem I was having, turned out to be replacing ALL of those resistor packs - with machined sockets installed, so the resistors can move a bit without breaking, and using a value of 2.2K!  Other than installing extra video RAM, putting in a battery holder, adding a reset line... and replacing the video PAL with that "Turbo Video" PAL from OPA (thank God it was already socketed)... replacing the resistor packs was probably the biggest work I did on my Geneve!  I think there was a 32K mod I did, too??!... I'm not sure, it was DECADES ago.  I did modify a Myarc 512K card as extra RAM for the Geneve... but that's a separate card, of course (that was pretty easy too)!

[+InsaneMultitasker]

5 hours ago, Restricted-Access said:

I had a couple of problems with my Geneve... over 30 years ago (give or take a few years).  I don't remember who I talked to, but I believe it was Don Walden.  I also don't remember the issue anymore, but I remember what ultimately fixed it (Tim, you may know or have heard about this - hopefully, Don made notes, since I can't remember what the problem was... I think it may have had something to do with the clock/date)

Anyway... Don was asking me to check the resistor packs (there's 4 of them: three 10-pin, one 6-pin).  One of the things I noticed, was one of the longer resistor packs... had a hairline crack in it!  It was barely perceptible.  In fact, you could only see it... if you flexed the MB slightly, and then you would see the split in the resistor pack (talk about your intermittent problems you can't see)

Don liked to take the calls and this was most likely a problem he helped to resolve.  The calls I took (and participated in) were usually related to software, otherwise I was usually busy doing hardware work.

 

The cracked resistor networks can be very hard to spot.  I usually check them first by running my fingernail over the top to feel for any cracks and secondly, by using a black sharpie to 'paint' the top edge of the resistor network.   Once dry, the crack usually shows itself, and pressing on one side of the resistor network will confirm.  I would not recommend too much flexing of the board to avoid creating new intermittent problems.  

 

I would have to look at my notes to be certain, but I believe that the resistor networks are 1K.  The one near the neck of the card is usually the one that gets damaged, and I've only had to replace a very small number of interior resistors.  The latter usually happens when someone stores the card without a clamshell and no protection from other cards, parts, etc.

10 hours ago, Restricted-Access said:

Also, if you are not concerned about RF bleed... you could use some steel wool to strip that coating off!  In any case, it IS a plastic shell... it's just a conductive coating inside to block RF signals. ?

Good info!   It's been so long, I don't know if I ever tested the outside of the plastic cases.  The coating makes sense.  I'll have to look at one more carefully now.  The warning still stands regardless of the shell or coating, as I've repaired my share of cards placed in the incorrect case   

 

[+InsaneMultitasker]

I found my old 3.5" miniscribe today, hiding among some books I had packed away 10+ years ago.  When I plugged it in, the drive didn't fire up.  I remembered that whenever I shut down my system to attend the Chicago or Lima Faire, I usually had to nudge the stepper motor a bit then reset the power.  The stepper was frozen in place, so I gently applied pressure until it moved.  I turned on the power and the drive came to life, but the stepper couldn't move beyond a quarter turn.  I turned the drive off again and slowly, manually rotated the stepper nearly 3/4 turn, and did this a few times.  This time the drive spun up to speed and the seek test succeeded!  I was able to access the files and directories, most from the mid to late 90s.  I determined that the files had long since been transferred to my SCSI media.   Still, it was fun to hear the ol' drive spin up and seek for files after so long.