Gents,
just a question regarding a floppy controller from IBS sold as AP53.
Does anyone know the history behind while the raw pcb is marked as AP41 ?
Picture Source: https://www.facebook.com/photo/?fbid=3150692075074619&set=pcb.10162824251778677
Thanks...
Perhaps that is an internal part number for just the PCB?
That card is SUPER interesting though. Unlike a lot of MFM floppy controller cards it doesn't appear to use any chips that aren't fairly readily available with the exception of the 28L22N, which I think is a bipolar PROM. That could be replaced with another EPROM. It would be interesting for someone to clone this card in a modern buildable version.
Do you have the software to use it? Is there support for CP/M or reading other formats like 360K PC floppies or support for DOS 3.3 or ProDOS formatted floppies on higher density medai?
Fascinating!
This is a clone of the apple2 DISK II controller with a stub to drive alternatively PC drives but use them like DISK II drives minus ability to half and quarter step in GCR mode. No MFM here. Replacing the bipolar PROM with an EPROM would lead to amateur made contemporary DISK II controller cards with their huge incompatilities due to slow EPROMs ;)
So it controls PC style floppy drives but only in GCR and can't read PC format floppies? Still interesting. Can it control double sided and 80 track drives or just 40 track single sided 160k ?
There are quite a few contemporary designed floppy controllers which use EPROMs instead of BiPolar PROMs that work OK, but you do need to use fast enough EPROMs, the -450 versions of course probably won't work.
Now you started explaining things to me ;) How fast is the D2732C PROM on this card that already replaces one BPROM?
The 2732 on the card probably replaces the code used for the boot. The one that would be more speed critical is the one that is used for the Woz state machine.
I can't find a datasheet on that PROM, but the access time on typical UV erasable 2732 is between 200ns and 450ns. I've seen the 200ns parts used without any major issues on modern floppy controller designs for both the P5 and P6. I could certainly see possibilities of the 450ns parts being too slow for use with the P6 (state machine) but they'd probably work OK for the P5 (boot).
And do you think supposedly German engineers were that stupid not to replace the "more critical" BPROM, too? That's why I asked that question ;) The 250nS 2716/32 EPROMs were widely available in 1984 already.
Back in 1984 BiPolar PROMs were readily available and cheaper than EPROMs. It would make sense they would use that when it was cheaper. For the 2732 there weren't BiPolar PROMs that stored 4KB.
The datasheet for the TBP 24/28 series is here. The typical access time for the 28L22 (a low-power, slower part) is 45 ns.
Had the BPROMs been cheaper at the time of production of the pictured card why did the engineers of that card use a 2732 instead of the cheaper and more compact BPROM ;)? Obviously only a small amount of that 2732 memory is used in a DISK II controller clone. The rest is wasted.
Assuming that it only has a Disk ][ style 256 byte boot code in it, maybe. A lot of other disk controllers like the LiRON which support other than just Disk ][ drives have much larger firmwares. A bunch of vintage period disk controllers like the MicroSci, Franklin and Rana Systems ones use an EPROM also.
I'm guessing if this IBS card used a 2732 instead of a 2716 it was because they needed 4KB instead of 2KB. Do you know the IBS only uses 256 bytes? If they needed more than 256 bytes, most of the BiPolar PROMs were only 128 or 256 bytes so that wouldn't have worked for them and forced them to use something else. I think there might have been some BiPolar PROMs that were 512 bytes, but I don't think they were very common if there were. At least I can't recall anything for an Apple II using one back in the day.
The PROM I was looking for the datasheet on was the NEC D2732C which is I believe a write once version of the common 2732 EPROM. I'd suspect access times to be more typical of that style of chip which are usually 150ns or slower. 200 or 250 are pretty common.
Erphi like 2 .jpg
Erphi like 3.jpg
duplicate pics deleted
Thanks Wayne! Those look like different layouts of the same basic design.
Well their is some action ongoing at a German Forum to rebuild the Ehring FDC-4 Disk Controller which seems to be compatible with the mentioned AP53 card:
https://forum.classic-computing.de/forum/index.php?thread/36150-ehring-fdc-4-disk-controller-nachbau-tbp28l22-programmieren/&pageNo=1
The actual discussion is around the similar and/or same interface layout found at some clone cards. This was the reason to raise the above question, because we didn't find any background information yet, describing while the PCB is marked as "AP41" while the whole card itself was sold as "AP53".
Personally I don't believe that the pcb was "wrongly?!" marked this way, because other pcb cards from IBS are marked correctly.
@softwarejanitor: to be honest... I don't have any software nor any additional information, yet.
It's entirely possible it was just a mistake or even that they originally intended it to by AP41 and then changed their mind later.
I hope you are able to find the software and docs for this card or one of the compatible clones of it.
I already told you it was a DISK II controller with no special software for it. Presently PC floppy drives cost more than DISK II drives and with such controller PC drives would not be able to half and quarter step so there is no advantage in using such controller. I think I own a couple of these controllers. Knowng the humble abilities of the German cloner I doubt the result would be rational but JLCPCB and similar allow such projects to exist nowadays.
The first pic from post #13 seems to be an ERPHI-clone, the second one is an original Ehring-FDC4.
The pic in post #1 is an IBS-AP53, which is basicly an FDC4 clone.
For what reason ever, the circuit board of the AP53 was marked as AP41!
For all of theese a special patch software is needed, to access higher capacity and double sided operation. This may be the same for the FDC4 and AP53, they are nearly equal, but the software for the ERPHI is definitely different.
The FDC4 is able to drive 2 shugart or 2 APPLE drives, but not at the same time. As far as i know, a mix is possible, but it's not allowed to connect an APPLE and a shugart drive as drive #1/2 at the same time
Regards
How higher will the capacity be, and can you post that software or link to such software for non-erphi controlers? Not talking about 40 tracks general DOS 3.3 patches.
The zip contains an ADTPro disk image, the disk is not bootable, load a standard DOS 3.3 disk and change disks, or run PATCH165 from another drive.
Patches are available for DOS3.3 , UCSD , CP/M.
Info for the original FDC4:
(Hope i remember them correct ...!?)
SW1: On/Off - Drive 1: Shugart/APPLE
SW2: On/Off - Drive 2: Shugart/APPLE
SW3: not used
SW4: On - automatic doublesided operation
The Shugart bus supports drives with
2 x 40 tracks (360k)
2 x 80 tracks (720k)
Note that not all doublesided 5,25" drives are working with the APPLE, and they are hard to find today. Unfortunately i don't have a list of working drives. ;-(
The Shugart bus supports drives with
2 x 40 tracks (320k)
2 x 80 tracks (640k)
Some more info can be found here:
https://www.applefritter.com/appleii-box/H085_AppleIIFDC4.htm
Good information from the late speedyG. My German is weak but the article appears like it kind of explains why the EPROM is that big. It apparently does have more than just the 256 byte boot code most clone controllers usually copy more or less directly from Apple's Disk ][ Controller Card.
The 320k and 640k floppy options with patched OSes and other OS support is really what makes this card interesting. If it were only a limited Disk ][ level controller that worked with 35/40 track single sided Shugard bus drives then it wouldn't be all that useful.
Of course these days all floppies are more or less for nostalgia, but that's OK.
I'm wondering if this card would work with something like a GoTek to do 320k and 640k images? That's really probably more of a fun-to-do thing than practical, but do much retro stuff is that anyway.
It is big because it was cheaper then a PROM. Look at the 8 address lines connected to the EPROM in the schematic in the article -- only 256 bytes of it were used.
transwarp2 wrote:
...Knowng the humble abilities of the German cloner I doubt the result would be rational but JLCPCB and similar allow such projects to exist nowadays.
Dear transwarp2,
Thank you for the compliment. Building my first smart home with an Apple II and an FDC-4 in the early 1980s paved the way for my professional career. Thanks to it, I can support my family without any worries, and I am delighted that almost 40 years later, so many people are still working on this topic — for example, on this discussion board.
Bildschirmfoto 2025-06-12 um 18.38.53.png
Having a circuit board made used to be a very laborious and expensive process. There was usually a minimum order of 100 pieces. That's why I opted for the wire-wrapping technique. The photo shows the Smart Home relay output stages being switched by the Apple II.
Bildschirmfoto 2025-06-12 um 18.40.29.png
Today, conditions are like paradise: It's no longer unusual to buy a 3D printer or laser cutter in a supermarket, for example, or to have high-quality circuit boards produced cheaply by JLC. The freely accessible Asimov FTP collection, which contains information on Apple II computers from around the world, provides unlimited opportunities to supplement your knowledge of Apple II computers. Hopefully it will still be around in 50 years' time for future generations.
In any case, I'm really looking forward to revisiting this topic, rebuilding the long-forgotten hardware for fun and archiving it in a freely accessible digital format. You are welcome to help with this. Don't get frustrated!
Best regards, Joerg
Our society is hungry for any working force; you have self-esteem as if you invented the computer in your picture..."In the kingdom of the blind, the one-eyed man is king".
Wow. That is a very unkind thing to say.
If you continue to behave like this, you'll be banned.
This thread with the mysterious floppy controllers piqued my interest and so I ventured into my basement to find my old Apple II slot cards - from my (fading) memories I seemed to recognize some of them to possibly be in my possession.
I happen to have both FDC slot cards as seen in the post #13 by 'Wayne', although the mine have some peculiarities:
The equivalent (or knockoff) of the top card I have is labled "HOCO-FLOPPY-CONTROLLER" in copper trace letters on the left side and it has a serial number field with hand written "422" in it. The traces are all straight segments while the specimen seen in post #13 has rounded traces which back in the day only was possible with hand glued traces on mylar. Although some irregularities and imperfections of the trace angles and distances in my "HOCO" specimen also hint at hand glued traces.
The equivalent of the bottom card (with the yellow silk screen) I have seems to have the exactly same layout as the one in post #13 and the narrow traces and the 90 degree corners look like the layout was done with a CAD tool. But it also could have been a very skilled glued layout. The back side has the letters "LMD COMPUTER FDC-CARD" and at another place the number 1009 582 in two lines. On the backside there also is a tiny "RE" - possibly the initials of the designer or layouter - and the clue "FDC 4" which means this was his 4th attempt ... the PCB manufacturer (rademacher) also added their logo. What I find peculiar is that the specimen I have has been hand soldered. Maybe these things were sold as kits or naked PCBs ?
Anyways, all these cards contain a 100% faithful knockoff of the original "Woz Machine" and I have read out and compared the contents of their state machine PROM with the P6 PROM of an original DISK II card, all of them have an identical contents, and the checksum is 68F6.
The 1980s were the Wild-West era of microcomputers, and everybody cloned everything worth cloning and there were clones of clones of clones. Oh, and don't get me going on all the copying of "copyprotected" diskettes going on at the time - all completely legal back then, although beginning with the mid 1980s, laws had changed and parasitic lawyers started to set up traps for school kids to blackmail their parents for money by cease-and-desist letters (the kids were too young to be prosecuted).
(If you are interested in this aspect of microcomputer history, read the P.S. below - it's memoirs from the "software pirate" scene in the Germany of the 1980s, and the consequences and repercussions - I think the USA scene was different due to different laws, but still, the psychological motives being all this were the same - humans are greedy and this causes them to deviate from the honest way to make a living, and this deviation, for some, may be deadly. So it's not just a harmless game played by teenage school kids)
- Uncle Bernie
P.S.: A few anecdotes on the German "software piracy" scene of the 1980s (from Uncle Bernie's yet unpublished memoirs)
One of these parasite extortionist lawyers was a certain Guenter Freiherr von Gravenreuth who responded to ads of school kids in the classified ads section of the computer magazines of the time, in which the kids sought "software to trade and swap" and then incited them to send him pirated copies, and this means, this evil parasite incited school kids to commit what just recently had become a crime. And then he extorted money from their parents. Consequently, he got so many death threats that he obtained a licence to own and carry a conceiled handgun - which in Germany is almost impossible to get, even if you can show actual death threat letters. The German government is not concerned with the life, safety and well-being of ordinary citizens, and never was. In Germany, only certain politicians, Attorneys of the State, and members of the repression apparatus can get a license to carry a gun. But the story has a very satisfactory ending: Grafenreuth committed suicide with the very same handgun he had a carry license for, when he had received a prison sentence for fraud in Y2010 --- according to the website:
https://de.wikipedia.org/wiki/G%C3%BCnter_Freiherr_von_Gravenreuth
... he claimed "family, financial, and health problems" as the reason for his suicide. Seems his blackmail operation had run its course and could not support his lifestyle anymore. And I know (alledged insider knowledge I was told at a cracker party) that he had developed some mental disorder due to all the death threats for his evil activities (paranoia and depression was mentioned). In the above wiki page (in German, but you may try google translate) there also is the story how he set up his traps to ensnare school kids and then blackmail their parents. What a vile creature. Good riddance ! He should have sought some more productive and honest way to make a living. And probably would still be around.
The consequence of these activities of these blackmail lawyers was profound, the classified ads for "software to trade and swap" disappeared from the computer magazines, and those magazines who relied of the revenue from these ads folded. Most disappeared in Y1988. There was a big shakeout.
And the 8-bit software piracy / "cracker" scene continued underground. But soon withered away as software companies stopped producing software for these 8-bit machines where almost every owner was a "software pirate". Which is a bit of a misnomer, IMHO, because what real pirates did was to assault and board ships on the high seas, killed everyone not valuable to them, and took all the valuable cargo, and some of the passengers were held for ransom or were sold as slaves (see: https://en.wikipedia.org/wiki/Barbary_corsairs) ... and these where white people sold as slaves, mind you. About 1.2 million of them.
So-called "Software Pirates" didn't do any of that.
I could go on and on about the software piracy scene of the 1980s but I think enough is enough. I just wanted to give you some background info and memoirs from the time, so you can better understand why everybody (even "honorable" businesses) cloned, copied, and ripped off everything they could get their hands on, software and hardware alike. Such as the FDC cards in this thread. The "Wild West" era of microcomputers indeed !
-UB
There always has been arguments here on Applefritter (and on other forums, too) whether it is worthwhile to clone the DISK II card or related cards which contain DISK II "DNA". The counter argument against doing so usually is that millions of original DISK II cards are around. You still can get them on Ebay for somewhere between $40 and $60 (including sales tax and postage). Where this really hurts if you live outside the USA and your postage triples or quadruples. Outside the USA, the DISK II is not as abundant and what you can get mostly are clones of the original DISK II card.
But my take on this is that reworking / redesigning the DISK II or related FDC cards may have merits when these designs are put into the public domain. An open source design of 100% DISK II compatible FDC cards would enable makers and builders to adopt this design and add features. Such as adding the Shugart bus (these FDC cards are the topic of the OP above, and the follow up posts). I also think that some diagnostic hardware could be added which would allow tracing of the loading process of copy protected floppy disks, for better understanding how these copy protections work. This not only would help with perfecting Floppy Emus, but also help with documenting copy protection techniques which were used with real diskettes for the Apple II (these already have often deteriorated badly, and this does not help attempts to preserve this knowledge for posterity).
THE ISSUE WITH THE BIPOLAR PROMS
Anyways, some obstacles mentioned in the above posts should better be avoided, such as the use of fuse link PROMs, two of which are in the DISK II, and even back in the 1980s they already were technically obsolete, difficult to buy in smaller quantities, expensive, and almost nobody, at least no hobbyist, had a professional programming system able to program them reliably. You had to use the services of "Programming Service Providers" to get your PROMs burned. This is why we can find so many small EPROMs on most of the third party FDC cards for the Apple II, but not made by Apple. These small DIL-24 EPROMs replace the P5 PROM (256x8) of the DISK II card containing the bootstrap loader. With a larger than 256 bytes EPROM they could play tricks like having a different page for each possible slot number. The original bootstrap firmware (still copyrighted by Apple, mind you !) was programmed such that it worked in any slot and the slot number multiplied by 16 was held in an index register. Now, if there is enough space in an EPROM for having individual memory pages for each slot, this trick with the index register is not necessary and the code could be changed in subtle ways, hoping to dodge the copyright of Apple on their firmware. This explains why many of these third party floppy controller slot cards have 6502 code inside their EPROMs which does not match Apple's code in their P5 PROM. And this may bring incompatibilities. And then, owners of these cards programmed an EPROM of the same type where all available pages had a 1:1 knockoff of Apple's P5 code in them, fixing the incompatibility problem.
THE ISSUE WITH SMALL EPROMS
These small EPROMs (types 2716, 2732) in DIL-24 are still available but they get scarcer, I observed the EPROM market over the past 25 years. Some EPROM programmers of more recent manufacture do not support them properly or not at all. So I would recommend to adapt any re-development or clone of these clones to have a footprint for a DIL-28 EPROM, (types 2764 to 27512) with appropriate solder options on the PCB to be able to configure that footprint for any of the EPROM types in that range.
THE ISSUE WITH THE P6 PROM
The "P6" PROM on the original DISK II card contains part of the famous "Woz Machine", a small state machine which also comprises four flipflops of the 74LS174 and the 74LS323 "Universal Shift Register".
The same issues with sourcing and programming these PROMs has led to the above discussion on replacing it with an EPROM. This is of course possible, if the EPROM is fast enough. It does not need to be as fast as the bipolar PROM, though. But note that just taking the ~2 MHz clock period (~500ns) of the 'Woz Machine' into account is a fallacy. There are more moving parts and more timing criteria at play. The critical Q3 clock edge within PHI2 comes ~286ns after the begin of the PHI2 phase. The address decoding logic typically takes ~70ns to activate /DEV on the DISK II card (this is from measurements, and not specified anywhere in the Apple II manual, and in corner cases it may be more, conservatively, I'd use at least 100ns to add 30ns of safety margin). The 74LS259 (aka Fairchild 9334) mode register takes another 20 ns (max) from its enable input tied to /DEV to a change in the mode affecting the 'Woz Machine'. The 74LS174 has a data setup time of 20ns but the 74LS132 clock gate cuts us some slack of typical 15ns ... but it could be faster, so there may be less slack. Conservative design would ignore the added slack and work with the full 20ns of setup time (no, you could not build a Cray-1 if you are so conservative). So the access time needed for an EPROM replacing the P6 PROM is:
286ns - 100ns - 20ns - 20ns = 146ns
... and you will be hard pressed to find a 2732 EPROM with 150ns address to data out access time. These speeds were not feasable on 1980s era NMOS processes. But in the mid 1990s and up, EPROMs with 150ns access time and faster made on CMOS processes were abundant. So replacing the P6 PROM with an EPROM is doable, but not very elegant.
A MORE ELEGANT SOLUTION TO REPLACE THE P6 PROM
More than 20 years ago, I faced the problem that some of the DISK II cards I had bought in a huge bundle of Apple II hardware were defective, and this was traced to bad bipolar PROMs (it always was known that fuse link PROMs are somewhat unreliable as the fuse links can "grow back", and worse, these fuse links need a passivation opening over the fuse, so with bipolar PROMs in any non hermetic package a fuse link also might corrode away and open the fuse, the reverse of fuse grow back).
In the early 2000's it was already difficult to find these 256x8 PROM blanks at a good price, so I read P6 out and turned it into logic equations which would fit into a P22V10 PAL. For P5, I had no choice other than to use the expensive PROMs --- there is no way to put a 256 bytes long 6502 code page into a PAL.
With my P22V10 substitute for the P6 PROM, and maybe two of the expensive new P5 PROMs, I was able to fix all my DISK II cards.
AND THE FINAL PROBLEM: THE ELUSIVE 74LS323
Lo and behold, in one of my Taiwanese (?) knockoff floppy disk controllers, which already had come with an EPROM to replace the P5 PROM, the 74LS323 was bad. And even back then the 74LS323 was difficult to find. No distributor had them in DIL-20 anymore. And that was 20 years ago !
The reason is that the 74LS323 was hated by TI as it was a 2nd source of an AMD IC which never was very popular. Much more popular was the "brother" of the 74LS323, the 74LS299. It's the same, drop-in function except that the '299 has an asychronous clear input while the '323 has a synchronous clear input. In many applications where the clear input is only used during power up reset, or not used at all, the '299 can drop right into such a '323 socket. This made the '299 more popular than the '323 and as a consequence, the '299 was implemented in almost any process technology / logic family replacing the old bipolar versions: 74HC299, 74HCT299, 74F299, 74AC299, 74ACT299 ... all of these exist and are abundant. You can find them almost everywhere where 74xxx logic is sold. The '323 is not easily found.
We can still get 74LS323 on Ebay, new-old-stock, in small quantities, and at high prices, and when postage is added, often > $10 to just get one of them. Distributors like Mouser do not have them, and Digikey does have them in their "marketplace" (a third party) but there you have to buy them "in bulk", 199 pcs at once, at $1.51 each (today). These were made by Texas Instruments (TI) but a search on www.ti.com shows no offer - so unless TI's website is broken (it offers 74LS32 instead, stupid !) they probably don't make them anymore. This means we will sooner or later run out of 74LS323.
The 74xx299 is the only viable alternative.
And when the P6 PROM has been replaced with a P22V10 PAL (or GAL) which has 10 outputs, but only 8 are used to replace the P6 PROM, then two outputs are left over, and I used one of these to make a control signal which drives the asynchronous input of an '299 to make it behave like the '323, at least in the DISK II controller and all knockoffs using the copycat circuit.
THE P6 SUBSTITUTE GAL AND THE 74LS299 ON TRIAL
It works ! See this photo:
DISK_II_with_74LS299.jpg
And this is how I would recommend to redesign the DISK II circuit (and the related knockoffs), and of course, the P5 PROM should also be replaced by a DIL-28 EPROM as suggested above.
For most people who want to experiment a bit or add their own functions to this basic design, this little mod / substitution solves all the problems with procuring rare bipolar PROMs and the elusive 74LS323.
CONCLUSION
I think that anyone with a "vintage computer" lab equipped with a stash of TTLs and some EPROMs could probably build such a DISK II substitute for less than $20 in parts, including the PCB (if sourced from a cheap PCB manufacturer). If building one based on bipolar PROMs (if you have the PROM programming system) the two PROM blanks alone may cost you more than $20.
If turned into an "open source" solution this would also allow all sorts of add-on functions and circuit bending.
- Uncle Bernie
That's a pretty interesting way to deal with the issue. A Disk ][ card clone made with 74LS299, 22V10 and an EPROM or EEPROM would be a great alternative. If there was a PCB design with Gerbers and the .jed for programming the 22V10 it would be a pretty easy project for people to build.
The issue is imaginary, or just a wishful thinking. There are more DISK II controllers and exact clones than apple2 fans/market needs now and on my forecast in the following decades. This was the most massively produced apple2 peripheral card all over the world. I know of local storage of hunreds available to be released to the markert. $30 is the average ebay price with free worldwide postage for vintage 100% DISK II controller clones. But of course the granddaddy who made all ICs in the world should use any convenient moment to make hidden advertisement of "his projects". The fusible link PROMs are manufactured with different technologies, many less vulbnerable to link deterioration with time, I am fan of Signetics ;) They will outlive several generations.
In post #33, 'transwarp2' wrote:
" But of course the granddaddy who made all ICs in the world should use any convenient moment to make hidden advertisement of "his projects". "
Uncle Bernie comments:
Please confirm that you meant me with this nonsensical slur.
- Uncle Bernie
It is an under handed insult from someone who obviously has nothing of value to contribute himself.
Dear readers of this thread:
Don't pay attention to the nonsense spewed by that troll aka 'transwarp2' in his post #33. And I don't even mean his childish "ad hominem" attack on my person, but the nonsense he spews about fuse link PROMs "outliving several generations" and about his "hunrets [sic] (of Disk II clones) "available to be released to the markert [sic]".
Note his spelling - hilarious ! Him obviously not being a native speaker of the English language leads to the conjecture that he may be linked to a known Bulgarian group who sits on lots of electronic junk left over from the collapse of their Communist computer industry which once made clones of the Apple II under the "Pravetz" brand name.
This is the root motivation for his trolling in this forum and elsewhere !
My take on the "market" situation for 40+ year old Communist electronics junk:
Well, if you can get a piece of this low quality junk pretending to be a DISK II clone card for $30 including shipping, and if it works, fine. If it does not work, not much money was lost. But keep in mind it's Communist made junk, with ICs of dubious quality made on inferior semiconductor processes, and that the IC packages may be metric (2.50 mm pin spacing instead of the 2.54mm the Western World did use). So if any of these low quality ICs fail, you will struggle with replacing them, although it is possible to do this. And fail they will. In droves. Guaranteed. None of my chess computers made in GDR works anymore, due to the Communist made ICs in them just being low quality trash. The inferior 1k x 8 ROMs are the worst. I still wonder how it is possible to screw up the design of a humble mask ROM. Maybe it was intentional sabotage and not ineptitude. The Communist work ethic was: "They pretend to pay us, and we pretend to work." - - - This, Ladies and Gentlemen, is the root cause why the Communist Eastern Bloc under the thumb of the Soviet Union collapsed in Y1989, and not, as rabid Marxists claim to deceive us, due to the "Glasnost and Perestroika" policies of Mr. Gorbachev. That policy was just a well meant but futile attempt to radically turn the course of the ship around and away from the (economical) cliff, metaphorically speaking. 70 years of Communist rot, lies, brainwash, deception and repression can't be undone by any political program. The collapse of the Communist Eastern Bloc economy was inevitable.
Caveat Emptor !
This said, buy Communist electronics at your own risk ! Caveat Emptor ! (And I do not imply their IC designers were dumb ... I had some of them coming from the GDR on my design teams ... all good engineers. The failure of the Communist semiconductor industry is deeply rooted in the Marxist planned economy system itself.)
Western vintage ICs may be problematic, too !
But we also must face the fact that even Western made ICs will not last forever. There are numerous deterioration mechanisms at play depending on whether the ICs are powered up or whether they are still in their tubes, "New Old Stock", and depending on storage conditions and the type of package (Plastic, CERDIP or Side Brazed Ceramic). The type of the bond wires also plays a role. Before we had CMP based copper metallization process technologies from the 350nm node on and below, it was aluminum metallization / bond pads and gold bond wires, which forms intermetallic compounds even when the IC never was used but was just stored over several decades. These intermetallic compounds are brittle and higher ohmic and are known to cause numerous functional and reliability problems.
So, over the decades ICs may deteriorate even when not being used. All other electronic components also deteriorate. Even the PCBs deteriorate (i.e. they may get brittle, may develop hairline cracks, and may develop an outgassing phenomenon when soldering, which was not present when they were new, possibly the epoxy chemically deteriorating: I did experiments to confirm it isn't just absorbed moisture) and the traces and solder joints corrode. It is all but impossible to keep any electronic system in fully functional condition for "several generations" (of humans). Anyone claiming "several generations" of useful lifetime for any electronics is just a fraud.
The challenge of keeping vintage computing hardware alive !
Every collector of vintage computing hardware knows this and has to change ICs and other components regularly to keep the hardware in working condition. Relying on 40-50 years old cards as "spares" often leads to disappointment, even if they were made in the Western world.
Same risks with relying on 40-50 years old ICs, even when these are "New Old Stock" - they may work initially and then fail after a few hours, days or weeks. This is why I did a one month 24/7 burn-in of all the ICs in my Apple-1 kits ... and had piles of "dead" ones in my "IC graveyard" (some photos of this "graveyard" are available on Applefritter, and yes, it was that bad).
My take on this is as follows:
If we want to keep our vintage computer hobby alive, we should seek ways to build new hardware from scratch, using newly made PCBs (if possible, with gold plated traces to slow down corrosion) and with newer ICs. Everybody who has experience with repairing vintage computers can see the writing on the wall.
This means we (and I mean the vintage computer community) must analyze, reverse engineer, and re-design these vintage circuits until, after many such steps, we have reached complete understanding of all the subtle details and are able to re-synthesize the whole digital logic of, say, an Apple II will all the most prevalent slot cards, at the push of a button, to pour the result into some FPGA. I consider my ongoing work using older 5V CPLDs as an intermediate step towards that goal. Trying to do this in one step most likely would lead to failure, because the system we want to re-implement is poorly documented and not fully understood as to the interaction of all the software base out there with subtle details and even bugs in the original hardware designs.
The only other alternative is emulation of the whole vintage computer system by software, which however can only give users part of the experience and all the "look and feel" of the real vintage hardware is missing. Still, software emulation is cheap to have for anyone who already owns a modern computer such as a notebook. The software emulation will only take storage space worth a few dimes. And it can help with investigating the fine points of hardware/software interaction issues mentioned above, because in a software emulator everything can be traced conveniently for later analysis.
CONCLUSION
There always will be vintage computer enthusiasts who will try to keep the original hardware running, and then some who will build new hardware, and then those who will embrace software only emulation. It all depends which experience is wanted and which financial funds are available to pursue the hobby.
But purchasing electronic trash which is flotsam from long bankrupt Communist cloning operations is never smart. The quality and reliability is just too poor, and the metric IC packages, if present, are an issue.
Before you buy that low quality $30 Communist clone DISK II card ripoff, you better spend $10 more on an original DISK II card made by Apple, or $10 less on the DIY project which was proposed here in this thread and promptly smeared by that troll. And you now know why the does that trolling, they just want to sell their worthless electronic trash for good money - your money ! So they troll every thread on every forum proposing any DIY project that may replace their Communist junk. And were consequently banned on most of these forums - only to be reincarnated with different names. Forum admins can't do much about it - in the age of VPNs it's playing "whack-a-mole".
And, BTW, this floppy disk project is not the mine. I'll just give the maker and project leader (who lives in Germany) my PAL equations for the "Woz Machine" so he can implement his project without using these problematic and elusive / expensive bipolar PROMs.
- Uncle Bernie