I found this interesting snippet on a US site:
On a “non-Xi” GTN, NavData, Obstacles, SafeTaxi and BaseMap are loaded internally from the SD card when you “update” and those products run from internal memory. Charts and Terrain are run from the SD card. When you load new Charts or Terrain databases the database update process simply “flips” the pointers to active and standby databases on the SD card (which is why it only takes a few seconds).
On the G500, only NavData is stored internally, the rest run from the SD card. On the G500 TXi all databases are loaded internally (the SD card can be completely removed when you are done with the update). On the TXi any SD card can (legally) be used for the update since the card is not accessed in flight.
The question of whether avionics cards are off the shelf SD (or CF) cards has come up many times.
It sounds like Garmin use non-hacked cards i.e. not specially formatted to prevent them being read or copied. It may be the same for Avidyne. To prevent database sharing, the S/N of the GPS is probably stored on the card. King used specially formatted CF cards. There are a lot of posts further back in this thread with various data points.
Indeed that was my first thought too. I’ll contact Jeppesen. Thanks for now.
If one card works reliably, and the other not reliably but sometimes, it does sound like a card with an intermittent fault.
If the other one works without a glitch, I’d claim warranty on the one you bought at Jeppesen and try another one. They are darn expensive enough.
I recently purchased a spare database card for our 430W unit (to rotate with the original one to ensure having the latest database update). The new card was delivered by Jeppesen.
Updates work fine on the PC but the card is not (always) recognized by the GNS430W unit . When taking it out and putting it back in sometimes fixes the problem and sometimes not. Did anyone else ever encounter a similar problem ?
Could it be a bad contact ? Should I try to clean the card reader and how should that be done ?
Any recommendations ?
Well, yes, SMT packages are easier but if you are building an early 1990s product then it is probably not SMT, and DIP packages are much more scarce.
In reality one can usually manage, because there is a huge industry flogging old parts. Plus Ebay. These range from cheap to very expensive… I bought some 20k Hitachi H8s for $6. Disti price was £9. Now they go for $20… There are some scenarios which can cause problems for production:
I suspect the last two apply to HBK. That leaves them with just one option: if they had to make a few k of these, they could build them. The PCMCIA housings are probably available. This is the exact same part as the Honeywell-labelled KMD550 cartridges:
Peter wrote:
128kbyte SRAM
These aren’t hard to get – Farnell list at the moment 47 different in-stock 1Mbit x 8 bit SRAMs. What’s hard to get is the SRAM in the package you designed the PCB for. There’s always an ample supply in a footprint that would require you to redesign half of your PCB…
Peter wrote:
No idea what LNAV/VNAV is.
You’ve never wondered what “LNAV/VNAV” minima on a Jepp plate means? :-)
That’s interesting. At work we don’t buy enough stuff to see this (100-1k quantities mainly) and being an old codger I have always used commodity parts (e.g. LM358, from 1972) over the fancy hi-perf single sourced stuff from e.g. Linear Tech. The commodity parts rarely go on allocation (the magic word which electronic parts salesmen love so much, because it generates panic buying and resulting nice bonuses 
). And we have big stocks of strategic parts, bought opportunistically on the US surplus stock scene. However, products like the KLN94 and KMD550 are mid-1990s designs and the problem there is getting hold of chips which are simply not made anymore e.g. 8k byte SRAMs. I still make one product, in 100-off batches, which I designed in 1991 and which uses a 128kbyte EPROM, a 128kbyte SRAM and a 32kbyte EEPROM and these parts are hard to get today. There is some obscure company still making the SRAMs. Of the EEPROMs, I last bought a load on Ebay (unused 1990s stock).
The 20MByte Intel linear flash used in the KMD550 will not exist anymore except maybe a few here and there (it was always a really obscure part) and HBK probably need a lot more of them.
What HBK could do, if there is enough business, is to emulate it with some modern chips and maybe a processor. But I doubt ther eis enough business and anyway the last person who can switch on a soldering iron left c. 2003.
There is a massive problem at the moment with many electronic components. Some are on 50 week plus lead-time, many are on “allocation” which is just rationing customers. On some parts order books are closed.
Old flash is a particular problem. We have just bought six figure quantities of one part to secure supply. Micron are shutting the doors on new orders.
