• Please review our updated Terms and Rules here

A tip for those designing new hardware for vintage machines...

JonnyGators

Experienced Member
Joined
Mar 9, 2020
Messages
187
Location
Attleboro, MA
If you're going to design new hardware to use in 30+ year old machines, maybe build it to last a bit longer than 2 years. I know I'd be extremely embarrassed if I designed, built, and sold a product, only to have it die in 2 years while a 30+ year old machine it was made for continues to work flawlessly.

On a related note - can anyone recommend an XT-CF card that is actually built to last? Tired of throwing away money on amateur garbage that isn't built to last.
 
I'm still using the original in a clone. This is from the time when you built it yourself from the PCB. There is the infamous "chuck mod" worked out on it. Uses a modified Hargle BIOS. I"ll add that the ICs are whatever I already had in my hellbox of parts. The CF card is an old 192MB one that I originally bought for use with a camera., Construction is all through-hole DIP ICs. The BIOS is a 2764 UV EPROM. I think it dates from around 2010.

How's that?

You are aware that you're perfectly free to design your own interpretation, aren't you?
 
Last edited:
14 years and still going is excellent, good for you. Not sure how to put one together though. Would love to get my hands on something that would last more than 2 years, and I am willing to pay. As much as I like fighting with MFM drives that are determined to fail, it's good to have an easy option that just works - and quite frustrating when even that easy stable option proves to not be.
 
In the case of XT-IDE/XT-CF card, premature failure sounds like a production problem rather than design.

'Mileage will vary', but to date, on my XT-IDE/XT-CF cards, I have seen only experienced failure of the 28C64 EEPROM. Sometimes corrupt contents, fixed by rewriting the 28C64. In those cases, maybe it would not have happened if I had the ROM write-enable jumper removed. In some cases, I had to bin the 28C64 because it would not rewrite. There were some 28C64 that would not rewrite initially, but would after I put them aside for a while.
 
'Mileage will vary', but to date, on my XT-IDE/XT-CF cards, I have seen only experienced failure of the 28C64 EEPROM.
That probably explains why my XT-CF is still working with the 2764 EPROM. I do have a batch of 28C64s, but have used them on other projects--and programmed on an EPROM programmer, not in situ. On the other hand, I have a XT-CF Lite (initial type with the Xilinx 5V CPLD on it) that's still cooking. Again, I assembled it myself, including programming the CPLD.

Just lucky, I guess. I'm thinking about putting a Quantum Bigfoot drive on the original one with the 192MB CF card.
 
'Mileage will vary', but to date, on my XT-IDE/XT-CF cards, I have seen only experienced failure of the 28C64 EEPROM.
I've never had a 28C64 fail Though i buy all my stuff from Mouser to build my XT-IDE cards, My genuine Rev 1 cards are still going strong after all these years, As are my genuine ( No cheap knock off crap )R2 and R4 Cards
 
My three four tips for long-term survival and service:
  • First, I try to avoid old components and use ones currently in production.
  • Second, I also use to limit the models of certain components - for example memories - so that's easier to stockpile them si at long term failures can be easier to solve across models.
  • Also, I try to avoid SMD due to the difficulty to repair them... DIP-built systems are much more gentle to the technician.
  • Finally, I tend not to use programmable elements other than memories or microcontrollers (and these only if really necessary). No PALs/GALs/CPLDs/FPGAs due that they obscure the design and in case the original schematics are lost, their failure can cost up the whole design at the long term.
 
I've never had a 28C64 fail Though i buy all my stuff from Mouser to build my XT-IDE cards, My genuine Rev 1 cards are still going strong after all these years, As are my genuine ( No cheap knock off crap )R2 and R4 Cards
I've struggled to find much in the way of options or choices when it comes to these cards, a few years ago I looked for an XTIDE card, and bought what was available at the moment. I'm wishing I did a bit more research, but I don't recall finding a whole lot in the way of options or choices, or clear information on what I was buying. I think at the time I could only really find an eBay auction.

So perhaps that's on me for going with a random listing of hardware I didn't know much about. How does one determine if they are purchasing something genuine vs. knock off crap?

Could anyone recommend where/what I could buy today? I'm not opposed to building things, but my soldering skills just aren't that great, and the goal here is longevity and stability, so I'm really looking to purchase a final product that is built and ready to go.
 
What on earth are you even doing to wear out an XT-IDE???


Did you wake up this morning and choose violence???
If "I" was doing something to wear it out, I wouldn't be pissed about the card breaking down.

I didn't choose anything, I'm just pissed at throwing money away on something that brokedown way too soon or easily.

The card has been sitting in the same computer for a few years now. Suddenly when I boot, it doesn't see any drive present. I put in a new flash card, one that matches other such threads that claim it will work, go through fdisk and formatting and such - but no luck. At first it worked, but then wouldn't boot to it. And now no matter what card I put in the thing, nothing sees anything present.

I paid good money for a product, 2 years later it does nothing. Should I not be a bit miffed at that? Clearly something was done wrong with the build of this product.

I just want to buy something that works. I don't understand why that is such a challenge for just about anything and everything these days. Does anyone make anything that works anymore?
 
Does anyone make anything that works anymore?
Funny story there, I recently was trying to find a robot vac that would work on shag carpet (TLDR: there isn't one) and I got a recommendation from the internet and ordered it. It was surprisingly inexpensive and had a full on spinning Lidar on top so I had high hopes.

Well, the first thing it did was aim for the stairs, drive right off the edge and land in pieces at the bottom.

So in answer to your question, no. :)

I wonder if this has something to do with where the components are sourced. I'm not too familiar with the problem of knockoff chips, but I've heard bad things.
 
Clearly something was done wrong with the build of this product.
That is not at all clear to me at this point. The only thing that is clear to me is that you are angry because something no longer works.

What is frustrating is that you seem to want someone else to tell you what to buy that will last longer. I could tell you what I bought about a year ago - and it worked the first time and still works. I wrote about it here. Before I bought it, I spent several hours of "due diligence" which largely consisted of going through all the info that @modem7 has archived and made available - a link was already provided but there is more on those pages. Then, I found out that only a small portion of the *many* boards that have been made (and all the versions) and sold, were available to me in an "I want it right now" fashion. So, I took a shot. If it was a bust, I would have written that, it wasn't so I wrote about the positive experience...so far.

I would like to know what happened to your card, exactly and specifically..with pictures and traces and, eventually a fix. Anger, I can get anywhere; stories with a happy ending because someone figured out how to fix something and shared how they did it are less common.

You will likely just go get another one and I hope you have a better experience.

The thread got me thinking about the CF cards themselves and I came across this advert/"press release" about, what looks like a premium card back in 2004, and, you can still get them here - but some of them are 4X more than I paid for the board that I bought and 6 CF cards. I wonder if it is better than this one. Thank goodness, I have enough experience to make a lot of back ups :)

PS @twmiller beat me to it because I had to be so verbose.
 
Last edited:
If "I" was doing something to wear it out, I wouldn't be pissed about the card breaking down.

I didn't choose anything, I'm just pissed at throwing money away on something that brokedown way too soon or easily.

The card has been sitting in the same computer for a few years now. Suddenly when I boot, it doesn't see any drive present. I put in a new flash card, one that matches other such threads that claim it will work, go through fdisk and formatting and such - but no luck. At first it worked, but then wouldn't boot to it. And now no matter what card I put in the thing, nothing sees anything present.

I paid good money for a product, 2 years later it does nothing. Should I not be a bit miffed at that? Clearly something was done wrong with the build of this product.

I just want to buy something that works. I don't understand why that is such a challenge for just about anything and everything these days. Does anyone make anything that works anymore?
Are you seeing the XUB screen at least? If not, the first thing I would do is re-seat and reflash the EEPROM.
 
When booting, it tries to find a master and slave device, but finds none present, and then tries to fail over to booting to the A: drive, which it will do if I have a diskette in the A: drive.
 
I'm a bit baffled how it happens that such a piece of hardware can "wear out".
Agree.
I don't have a XTIDE (full disclosure) I like PDP-11s.

I looked at the design online. Nothing in the design is a short lived component. I expect the problem is elsewhere.
I would look at the CF-CARD adapter. I have seen them fail (crap soldering,NO QA)
Hot swapping cards? That will kill a CF-CARD in the cheap adapters not designed for hot swap.
 
Tired of throwing away money on amateur garbage that isn't built to last.

I'm going to stand up for the amateurs here by noting that the completely and utterly homemade expansion board dinguses I designed and built for my Tandy 1000s (that include a form of the XT-CF circuitry) have been working for four years now with zero problems. The closest thing to formal electronics training I've ever had came from one of those Radio Shack Science Fair 150-in-1 kits... ;)

I also question exactly what would "wear out" on one of these things because, yeah, it's not as if there are very many moving parts. Are you pulling and re-inserting the CF card without powering the system off?

I put in a new flash card, one that matches other such threads that claim it will work, go through fdisk and formatting and such - but no luck. At first it worked, but then wouldn't boot to it. And now no matter what card I put in the thing, nothing sees anything present.

I had so many headaches with incompatible CF cards with my earlier prototype I built my board so I can directly plug a laptop format IDE->SD adapter into it. But I'm told that people's mileage varies with those. (So far as I'm concerned they're super.) FWIW, TexElec sells a version of their XT/CF that has an SD adapter sandwiched on top from the factory. I'm not going to vouch for it because I've never bought any of their products, and I can see from looking at the PCB board for it they omitted a data bus buffer, which is kind of bad practice. But since the SD adapter is hard-mated to the board with no cable you can probably get away with it.
 
I"m not hot swapping anything. I power down the machine anytime I'm removing or changing CF cards. My CF card still contains the same data as always when I test it on a usb adapter to check if my data is still there, but the xtide card will not see it anymore. Nor will it see other cards. Tried in multiple slots on the machine.

Computer is working perfectly fine.
Flash cards are working perfectly fine.
But when booting the machine with the xtide card in a slot and a working flash card that previously booted - it sees no device there.

Problem squarely exists with the xtide card. Not sure where to go next with this, as I didn't build it.
 
Back
Top