How important are the IWM features for the Apple IIc ?

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How important are the IWM features for the Apple IIc ?

Hi Fans -

 

as you might know, I'm working on my Replica 2e project which aims to produce a substitute for all Apple II from the early ones to the Apple IIe and the Apple IIc without using any of Apple's proprietary custom ICs, like the MMU, IOU and  the IWM. The link to the project thread is here:

 

https://www.applefritter.com/content/uncle-bernies-replica-2e-ww-prototype-apple-iie-replica

 

It is of course irrefutable that the Apple IIc has the IWM custom chip as it floppy disk controller, while the Apple IIe does not. Thanks to forum members which supplied me with a lot of links I was able to download and read Apple's IWM documents, and in some of them Apple claims that they never sold any IWM based floppy disk controller for the Apple IIe. If this is true, it's only the Apple IIc which has the IWM. But the documents may be misleading because that statement about "never sold" may have been true at the time the document was written, and they might have sold an IWM based floppy disk controller later.

 

I bought a few IIc when they liquidated them at a greatly discounted price, but this was a poor speculative investment, as back in the day I thought they would become cherished and sought after industrial design icons, which they indeed became, so I was right on that, but alas, prices stayed in the cellar, so I sold them off at a loss. I did not (and still don't) see much utility in an Apple IIc, as it has no slots. And so I never have bought any accessories for them, and I am completely ignorant about which special features the IWM in the IIc would bring ? (Maybe it was just needed to make their Disk II system work with a CMOS 6502, who knows ?)

 

So please, enlighten me about the virtues of the IWM in the Apple IIc, by posting comments here in this thread.

I'm still pondering if, and if so, how, to implement a IWM substitute. As I seek no direct drop-in solution I can cheat and could do a simpler solution. Just enough to make the IIc mode of the Replica 2e work, and not more.

At the moment I still can't run the Apple IIc firmware ROMs yet, so I can't experiment if they insist on the presence of an IWM or not.

 

I've heard rumors that the Apple IIc could use higher capacity disk drives ... involving the "FAST" mode of the IWM maybe ? Or was it just more tracks ? Or more sides ?

 

So what is out there for the Apple IIc in terms of floppy disk drives and how important it is (or isn't) to support those drives  ?

 

Comments invited !

 

- Uncle Bernie

 

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I've seen pictures of

I've seen pictures of prototype IWM based 5.25" disk controllers for the Appple //e, they've been posted here  For whatever reason Apple never shipped any to customers as far as I know, they kept selling the "Apple 5.25 Controoler Card" which was basically the same circuit as the Disk ][ Controller Card except for having one DB19 connector instead of two IDC 20 connectors.

 

The card Apple DID ship that has an IWM on it is the LiRON card, which was sold for 800k 3.5" Unidisk drives.  So Apple's claims should be more like the never sold any IWM based cards for the //e which were intended for 5.25" drives.

 

Besides the //c the IIgs also had an IWM in it as it was the other Apple II family machine that had an integrated disk controller.  And of course the early Macs used the IWM up until the SWIM chip came out that could also handle 1.4M B 3.5"floppies.  There was a Super Driver Controller card for the Apple II which  used the SWIM.

 

The //c can handle 800k 3.5" drives using the other modes of the IWM, so can the IIgs.

 

Apple never sold any 5.25" drive that was higher density, more tracks or double sided for the Apple II.  The only higher capacity 5.25" drives they ever sold were the "twiggy" druves used in early Lisa computers, and I think there were prototypes for the Apple /// but I am not sure Apple actually ever sold them.  The Twiggie drives were very short lived as the Lisa moved to 3.5" drives (Lisa 2) and then was quickly cancelled.  The /// also died around that same time after the too-little-too-late Apple ///+ (which was actually one of the niceest 8 bit micros ever built in a lot of ways).

 

There were 3rd party double density and double sided drives like the ones from Rana Systems.  They mostly used their own controller cards and required modified DOS.

Oh, I almost forgot...  If I remember right Apple did sell a 5.25" PC-style floppy drive for compatibility issues, but I don't think they ever sold it or made a card for it for the Apple II.  There were ways from 3rd parties to do something similar with MFM style floppies.

 

 

 

 

 

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The original Apple IIc (ROM 255) can only use regular 5.25 disk drives. Since the IWM configures itself as a regular Disk II drive controller by default, it's quite probable that the original IIc firmware does nothing extra with the IWM.

The updated IIc (ROM 0) adds support for SmartPort devices. This is the one disk feature that separates the IIc from a regular IIe with Disk II controller.

So the question is, does the ROM 0 firmware change the IWM registers before accessing a SmartPort device?

This PDF from the Asimov archive describes how the Apple IIGS uses the IWM to control a 3.5 disk drive. It's enlightening if you want to know more about how different IWM modes can be used from the Apple II, specifically how to configure the IWM to read a 3.5 drive.

Presumably, most of that info would apply to the IWM in the IIc as well, except that its 1MHz 6502 isn't fast enough to do it reasonably.

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You're right - the garden

You're right - the garden variety IIc cannot read Apple 3.5" drives, but it CAN read and write Unidisk 3.5" drives which are much slower, and are also "smart" having an on-board 6502 microcontroller and associated circuitry to communicate with the LIRON card and the IIc's IWM chip.

 

The Apple IIc+ also has an IWM chip, but it has a bunch of glue logic to enable it to reliably read and write the much swifter (and cheaper) Apple 3.5" drives.

 

And as mentioned, the IIGS also has an on-board IWM chip, but instead of it being a DIP-28 it is a PLCC 28 7 x 4 variant, although identical in function.

It should also be mentioned that the early Macintoshes, the Mac 512, Plus and SE all had a DIP-28 IWM chip aboard.

 

 

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I think the issue here being

I think the issue here being the IWM itself...

 

If ever there was an Apple custom IC that needed reverse engineering, this is the chip.

It's as important to Apple computers as the SID chip is to the C64.

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baldrick wrote:I think the
baldrick wrote:

I think the issue here being the IWM itself...

 

If ever there was an Apple custom IC that needed reverse engineering, this is the chip.

It's as important to Apple computers as the SID chip is to the C64.

 

Well, I dunno.  I think it's arguable whether the IWM is more critical than the MMU.  Maybe I'd buy than the IOU since those seem to fail less often.  But it would be awesome if there were drop in replacements for all three of those chips.

 

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 It's complicated.

 It's complicated.

 

softwarejanitor wrote:

The //c can handle 800k 3.5" drives using the other modes of the IWM, so can the IIgs.

The IIc can use the Unidisk 3.5" drive, which has a built-in (65C02 based?) controller to adapt the data rate of the GCR 3.5" floppy drive (500 kbit/s) to the slower data rate (218.75 kbit/s) of the SmartPort devices. It can't use the Apple 3.5" drive, which communicates with the host at the native data rate. The LIRON card has the same limitation. The IIgs doesn't have this limitation (and neither does the IIc+ because it uses DMA to the IWM chip). The Unidisk 3.5" was and is more expensive and slower because of this rate adaptation.

If I remember right Apple did sell a 5.25" PC-style floppy drive for compatibility issues, but I don't think they ever sold it or made a card for it for the Apple II.

 It was only compatible with early Mac SE and II without the SWIM upgrade.

 

Here is some collected information to identify Apple floppy drives:

Apple ][ disk drives:

 

Unidisk 3.5" Drive:                            A2M2053 (Only for Apple IIs with SmartPort. For IIgs, LC IIe card, or later ROM IIc; others require Liron or SuperDrive card)

Apple 3.5" Drive:                            A9M0106 (Apple IIc+, IIgs; or SuperDrive card in II, II+, IIe. Any Mac with 19-pin port)

Apple FDHD External:                        G7287 (Macs with FDHD SWIM chip or Apple II SuperDrive controller. Not compatible with Mac 128K or 512K. Works in 800KB mode with IIgs)

 

Disk II:                                    A2M0003 (can be used with Apple III and III+ with modified analog card)

            

Disk IIc:                                    A2M4050 (First drive with 19-pin Dsub; no pass-thru port)

Unidisk 5.25" Drive:                            A9M0104 (First 5.25" with pass-thru port)

Duodisk 5.25" Drive:                            A9M0108 (May need modification for IIgs)

Apple 5.25" Drive:                            A9M0107 (The only 5.25" that is compatible with Mac LC's Apple IIe card)

None of the 5.25" drives are compatible with a Macintosh 19-pin floppy port. Never connect them to one!

 

Apple /// disk drives:

 

Apple Disk III:                                A3M004

 

Macintosh disk drives:

 

Macintosh 400K:                            M0130 (Not recommended for FDHD SWIM controllers. Will not work with Apple's Apple II controllers)

Macintosh 800K:                            M0131 (512K needs HD20 INIT for HFS. Will work on Apple IIs only with 3rd-party controllers, no eject button)

Apple PC 5.25" Drive:                        A9M0110 (360KB DSDD PC disks. NuBus or SE PDS card, or early AST, Orange Micro PC cards. Not compatible with Macs with FDHD SWIM chips)

 

Compatability Chart

Apple Model

Adapter Requirement

External Drives

Apple IIe or earlier

Disk II or Apple 5.25" controller

Disk II, Disk IIc, Unidisk 5.25", Apple 5.25", DuoDisk 5.25"

Apple IIe or earlier

"Liron" controller

Unidisk 3.5"

Apple IIe or earlier

"Superdrive" controller

Unidisk 3.5", Apple 3.5", Apple FDHD

Apple IIe or earlier

Laser "Universal Disk Controller"

M0130, M0131, Laser FD-100c, Laser FD-356, Unidisk 3.5", Apple 3.5", Disk II, Disk IIc, Unidisk 5.25", Apple 5.25", Duodisk

Apple IIc

May require ROM update

Unidisk 3.5"

Apple IIc

None

Disk II (modified cable), Disk IIc, Unidisk 5.25", Apple 5.25", DuoDisk 5.25" (one drive only)

Apple IIc+

None

Apple 3.5", Unidisk 3.5", Apple 5.25", Unidisk 5.25", Disk II (modified cable)

Apple IIgs

None

Disk II (modified cable), Disk IIc, Unidisk 5.25", Apple 5.25", DuoDisk 5.25" (modified board)

Apple IIgs

None

Unidisk 3.5", Apple 3.5"

Apple IIgs

"Superdrive" controller

Apple FDHD

 

 

 

LC family Macintosh

LC IIe Workstation card

Unidisk 3.5", Apple 5.25"

 

 

 

Mac 128K, 512K

800K drive requires HD20 INIT for HFS support. HD20 INIT does not work with Mac 128 which can use drives only as MFS devices.

M0130, M0131, Apple 3.5"

Mac 512Ke, Plus, SE (not FDHD)

None

M0130, M0131, Apple 3.5"

Mac SE FDHD, SE/30, Classic, Classic II, Portable

None

M0131, Apple 3.5", Apple FDHD

Mac IIcx, IIci, IIsi

None

M0131, Apple 3.5", Apple FDHD

Mac SE, Mac II

PC drive card

Apple PC 5.25"

 

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Great work robespierre

Excellent breakdown robespierre, very thorough and clear.  Interestingly, the Mac 400k drive would work on the Laser 128EX and 128EX/2 with the onboard Laser Universal Disk Controller card you mention. I never tried a straight Laser 128, but if the Laser (second generation red label) supported any 3.5" drive, I bet it worked. The original, first generation  Laser 128 with the gold label did not support any 3.5" drives as I recall.

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One thing that the //c uses

One thing that the //c uses with the IWM is the asynchronous mode when writing(sending) data. This is used in the later ROM versions that support smartport.

 

To simplify the sending of the smartport data, the asynchronous mode of the IWM allows you to write (send) a byte and then poll the status reg in the IWM. When the next byte is due (to keep the 32us timing per byte up), a flag is set, and then the smartport code can react to this and write the next byte to be sent into the IWM. This simplifies the code as its not needed to be cycle accurate to keep feeding the IWM data every 32us.

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softwarejanitor wrote:I've
softwarejanitor wrote:

I've seen pictures of prototype IWM based 5.25" disk controllers for the Appple //e, they've been posted here  For whatever reason Apple never shipped any to customers as far as I know.

I am generally certain that I've seen them in the Used Computer Store in Berkeley a few decades ago when I worked there, but I can't speak as to if they were sold in a retail setting before ending up in the store or if they... grew legs and walked out of Apple's EVT labs.

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In post #9, rjustice wrote: "

In post #9, rjustice wrote:

 

" This simplifies the code as its not needed to be cycle accurate to keep feeding the IWM data every 32us ".

 

Uncle Bernie comments:

 

True that. Getting the write timing right in synchronous mode is tricky, especially if you use 6502 vs. 65C02 and want RWTS code which works on both. Some instructions have different cycle counts on the 65C02 vs. NMOS 6502, and the 65C02 also does no "phantom read" on the STA abs,x instruction which is essential for the original DISK II controller to work properly. Using the asynchronous mode (what a nasty misnomer, they should have called it registred mode, latched mode, or something else) will do the right thing for any version of the 6502, if the code is written properly. But I still wonder how they do the 40 us long "SYNC" bytes in the asynchronous mode. I'm still scratching on the surface of the IWM but I think it's possible to do a PLD based substitute without excessive IC expenditure. Not sure if a 32 MC PLD could do it. A 64 MC PLD is enough, unless the turn off delay timer is done with a counter. IMHO it's stupid to waste so many macrocells just to make a 1 second delay. I will do that with one external capacitor / resistor instead.

 

Mission objective of my "Replica IIe" project has suffered from mission creep and now also includes the Apple IIc. So there will be extra time and effort required. But I still hope I can do this in a useful amount of time. I don't have four years to waste like the guy who designed the Yellowstone floppy disk card. My scope must be more humble. I have allocated two weeks for a complete reverse engineering and substitute design for the IWM. And I'm not willing to spend more time on that. In two weeks my test run of "Wings of Fury" which runs 24/7 is complete and then I need my spare time to advance the Replica IIe motherboard design, and the IWM substitute must be put on a back burner, if not yet completed at that time. But I do understand that for a complete Apple IIc mode, a complete IWM is needed. Not sure yet if I could take out the 8 MHz mode, which I think was only used in the Mac. The Apple IIc has no 8 Mhz clock on the motherboard.

 

- Uncle Bernie

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additions

Some additions/corrections to my prior post #7:

The Apple IIc+ does not implement floppy DMA, but has a custom chip called MIG that arbitrates access to a 2KB SRAM buffer. By filling this buffer at the 500 kbit/s rate, the IWM can read or write a "dumb" 3.5" disk like the A9M0106 at its native data rate, even if the CPU only runs at 1 MHz. The Apple IIc+ also has a 4 MHz Zip Chip accelerator, but it slows down to 1 MHz during floppy access so the MIG is required.

The Laser UDC doesn't consistently support SmartPort devices like the Unidisk 3.5". Steve of BigMessOWires reverse engineered several versions of the UDC ROM, and found that the 2.1 and 2.3 ROMs from the "long" UDC contain SmartPort routines, but the 3.0 and 4.0 ROMs from the more common "short" UDC have those removed. The Laser 128 ROMs also appear to have lost SmartPort support between ROMs 4.5 and 5.0.

The Laser 3.5" floppy drive is a clone of the Mac 800 KB drive M0131 with a mechanical eject button added. It won't work with any Apple II controller made by Apple.

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This is my implementation

This is my implementation .Work fine as replacement on Apple IIc and Liron Card .

 

Can you suggest how to make full functional test ( all device and program that I test is work as expected with this replacement emulation of IWM ) 

 

 

 

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PlamenVaysilov wrote:This is
PlamenVaysilov wrote:

This is my implementation .Work fine as replacement on Apple IIc and Liron Card .

 

Can you suggest how to make full functional test ( all device and program that I test is work as expected with this replacement emulation of IWM ) 

 

[[{"fid":"39024","view_mode":"default","fields":{"format":"default","alignment":"center","field_file_image_alt_text[und][0][

Sweet!  In order to test more use cases you might need to try it in one of the early Mac models that used the DIP28 version of the IWM instead of the PLCC ones.  If it works with a wide variety of software tests including diagnostic software on those then I'd say it is highly likely to be GTG,

 

 

 

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Duplicate works has to be done ?

I saw the work of "PlamenVaysilov" of post #13, and I'm impressed - very nice solution of the interposer PCB. I will "steal" the idea from you if you show us the backside of the PCB. It seems you only do very small vias down and solder the pin header such that no pin actually comes up to the top side. This seems to be an elegant solution to the problem being that most TQFP packages for CPLDs/FPGAs will not fit between the pin rows of a typical DIL, so making these adapters is difficult ... and Plamen's solution could be the missing piece.

 

As for the IWM itself, simply I must do my own design, cannot avoid it, because I target much older PLDs, and can't use MachXO parts.   Because there ain't no MachXO parts in my basement, and only thousands upon thousands of smaller, older, PLDs and CPLDs from the 1980s and 1990s. I think that my IWM substitute will be a mix of 74xxx parts and some GALs. Maybe a 7C330. Don't know. I thought I had several 100's of the 7C330 but only found one tube. My mission is partly driven by finding a use for these PLDs I've collected over the part 40 years before I die. Because my worthless heirs will throw them into the trash, along with my lab instruments, my library, and everything else. So I better find a good use for these parts soon ! I'm not the youngest anymore ! (but still healthy enough for a Class 2 pilot medical).

 

Plamen's mission is different, he obviously sought something which would drop into a real IWM socket. I don't need that. So I can use more ICs.

 

I did  not build my IWM test adapter yet. But some progress has been made with the design. I found that if using the exact data separator method outlined in the IWM spec, and the IWM patent, it is impossible to accurately reproduce the exact timing (Q3 clock cycle wise) as the original DISK II controller.  This has been proven by simulation and compare of my own DISK II substitutes and the "new" design. The final contents of the read register however is the same, as long as the disk bit stream is not pathological and conforms to Apple's GCR rules. But the read byte may appear a few Q3 cycles later than in the DISK II. I do not know yet whether this difference matters. For normal floppy disks, it won't. But for copyprotected floppy disks using weird copyprotection methods it may make a difference. This must be investigated. I could put both state machines into my substitute, and use the original one for 7 MHz SLOW SYNCHRONOUS mode exclusively, and the data separator and shifter method of the real IWM for all other modes. This would guarantee 100% compatibility with any copyprotection that works on the original DISK II controller. For me, DISK II compatibility is of the utmost importance. It takes priority over a faithful 1:1 reproduction of the original IWM. But it is understood that the "added modes" of the original IWM also must work. Such that the result could be used in a Mac, too. Just in case.

 

Here is a riddle:

 

As said, the test rig is under construction, so I can't do hardware investigations yet.  I'm still trying to understand Apple's documentation. It is quite complete (U.S.-Pat. 4,742,448 naming Wendell Sander and Robert Bailey as inventors supplies fine points which the IWM docs found on the web don't tell).

 

But what I did not understand so far is how the IWM produces the SYNC bytes (bit cell sequence 0011111111) in its asynchronous mode (the "Mac" mode). In the synchronous (legacy) mode, it works like the original WOZ state machine of the Disk II controller, it just shifts "0"'s into the shift register during all writes, so if the software timed shift register reload which should happen all 32 CPU cycles does not happen, but happens after 40 CPU cycles, with a $FF value, than the SYNC byte bit cell sequence 0011111111 is written out to floppy disk. The two "0" of which a re coming from the empty shift register, and the "1"'s are coming after it has been reloaded with all "1"s.

 

But in asychronous mode, this programming approach is not possible. Because if the write data latch has not been written in due time (within the 32 6502 CPU cycles from the last write), the write underrun flag is set and the whole write operation is terminated deasserting the write gate signal. Actually, this is smart because a crashed or interrupted write routine will not ruin / overwrite the data of a whole track. But it thwarts the generation of SYNC bytes using timed loops. The only way I can see to still write SYNC bytes in asynchronous mode is to write them as a sequence of byte values like this:

 

1st byte:  00111111 (violates Apple GCR rules by not having MSB set, but does not harm anything)

2nd byte:  11001111

3nd byte:  11110011

4nd byte:  11111100

5nd byte:  11111111

6th byte:  00111111 (same as 1st byte, five byte sequence repeats from here)

         

Bytes 1 to 5 above produce the same 0011111111 0011111111 0011111111 0011111111 sequence of SYNC bytes on the floppy disk as the legacy method would do with 4 shift register loads spaced 40 CPU cycles (on the 6502) apart, but as we can see, it's only possible to write groups of four such SYNC bytes and not violating any of Apple's formatting rules, which is a limitation compared to the legacy DISK II controller.

 

This limitation could be overcome, though, by more elaborate programming effort, setting up the byte stream to the IWM with arbitrary bit boundaries. The 68000 in the Mac sure can do that but to me it looks awkward, inefficient, and would slow down the disk write processes.

 

So the question asked to the forum members is if anyone has knowledge of the disk write routines or the format specification used in the Mac ? Or can point me to some 68000 assembly code listing of Mac RTWS code to inspect ? (I'm not a Mac guy, buy can read 68000 code).

 

This is just to verify that there is no "hidden" feature somewhere in the IWM to write SYNC bytes in asynchronous mode of the IWM other than using the above five byte sequence method, which at the moment is the only way I can deduct from the documentation. If there is any other way (other than using synchronous mode) then I need to know it such that I can plan my hardware development platform accordingly.

 

These are the subtle things you find when reverse engineering based on docs and patents. This means making a plan / crude initial design   before   actually exercising the hardware. By doing so, apparent contradictions or "holes" in the spec / documentation may become more apparent than if using the other approach, just putting the original IC in a test rig and start hacking.

 

Comments invited !

 

- Uncle Bernie

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With the IIc smartport code,

With the IIc smartport code, it is sending the sync bytes exactly like you describe! 8 bit values including the zeros.

 

Have a look here at the source code, you'll see it send the first FF sync byte, and then the values from the 'preamble' list

Apple_IIc_Programmers_Guide_to_the_3.5_ROM_part_2_page174

 

The preamble list is on this page:

Apple_IIc_Programmers_Guide_to_the_3.5_ROM_part_2_page178

 

 

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I agree with Uncle Bernie

I agree with Uncle Bernie that the package Plamen has created is fascinating.  One issue building replacement parts that ideally fit into the space a normal DIP IC fits into is what Bernie mentions, the width of some of the parts.  But this package also looks like it is extremely short.  Parts that are too tall can interfere with cards in the slots, which can be an issue.  I'm thinking that it is possible to solder a small PCB directly to a low profile socket like this if the right kind of socket is used and the board is designed right.  If SMD devices are used, especially if larger oenes could be mounted to the bottom side of the board it might be possible to make a board that really doesn't take any more space at all than a standard DIP IC.

 

 

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I use this SMD DIL male

I use this SMD DIL male socket ...

 

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PlamenVaysilov wrote:I use
PlamenVaysilov wrote:

I use this SMD DIL male socket ...

 

[[{"fid":"39030","view_mode":"default","fields":{"format":"default","alignment":"","field_file_image_alt_text[und][0][value]":false,"field_file_image_title_text[und][0][value]":false},"link_text":null,"type":"media","field_deltas":{"1":{"format":"default","alignment":"","field_file_image_alt_text[und][0][value]":false,"field_file_image_title

 

Brilliant!

How hard are those sockets to find?

I have single line pins like that I could use, just would need two, but the DIL socket is probably a lot more stable and sturdy than that would be.

 

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UncleBernie,  you could join

UncleBernie,  you could join applesauce discord channel. I'm pretty sure there are knowledgeable folks who can answer your questions,  some of them being active authors of MAME emulator, others good in reversing mac protections... https://discord.gg/YrQKdwNhdR 

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softwarejanitor wrote:How
softwarejanitor wrote:
How hard are those sockets to find?

 

 

You can just bend the pins of a regular round-contact DIL-28 socket.

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CVT wrote:softwarejanitor
CVT wrote:
softwarejanitor wrote:
How hard are those sockets to find?

 

 

You can just bend the pins of a regular round-contact DIL-28 socket.

 

I guess I've never really used DIL sockets before.  When I've built things where I probably could have used them like W65C02 adapters for //e or Videx Softswitches I've always used SIL pins.  I will have to get some DIL in various sizes because they could be handy to have in stock.

 

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softwarejanitor wrote:...I
softwarejanitor wrote:
...

I guess I've never really used DIL sockets before.  When I've built things where I probably could have

 

It's more of a terminology thing than anything else. They are the same as DIP sockets these days. DIL is more generic term, while DIP is supposed to refer only to the plastic ones. Back in the day they had ceramic ones too, but now you can't find them anywhere.

 

So a regular round-contact DIP socket will work as well.

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CVT wrote:softwarejanitor
CVT wrote:
softwarejanitor wrote:
...

I guess I've never really used DIL sockets before.  When I've built things where I probably could have

 

It's more of a terminology thing than anything else. They are the same as DIP sockets these days. DIL is more generic term, while DI

 

It is more that the ones Plamen bent the short side pins over on are Male-Male, and normally sockets are Male-Female.  I have SIL Male-Male but not used to seeing DIL Male-Male, only Male-Female ones.

 

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This is standart parts for

This is standart parts for smd mounting and i am not bend any pins on this connecor .

 

 

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PlamenVaysilov wrote:This is
PlamenVaysilov wrote:

This is standart parts for smd mounting and i am not bend any pins on this connecor .

 

 

Nice.  It does look nice and uniform like factory made.  I will have to look and see if I can find those for sale.  I'm sure they're out there I just haven't ever looked.  Any particular search terms I should use?  Or soemthing like DIL Male-Male pns .254" Maybe?  Well, that didn't find it...  I guess I need to try a few different ones.

 

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softwarejanitor wrote:CVT
softwarejanitor wrote:
It is more that the ones Plamen bent the short side pins over on are Male-Male, and normally sockets are Male-Female.  I have SIL Male-Male but not used to seeing DIL Male-Male, only Male-Female ones.

 

The male-male ones are under headers: https://www.digikey.co.uk/en/products/detail/cnc-tech/220-1-28-006/3441520

The factory bent ones (for SMD) are indeed significantly harder to find.

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Beware of misusing these DIL adapters (bending pins ...)

In post #21, "CVT" wrote:

 

" You can just bend the pins of a regular round-contact DIL-28 socket.  "

 

Uncle Bernie comments:

 

If you meant a "machined contact" type socket, no, you can't bend those pins, because they will break off.

 

The same mishap (breaking off pins) would happen with the type of male/male DIL adapter Plamen uses, unless it is done carefully, like he may have done, unless they are off the shelf items already having these bends. It could be done using two pliers, one round nosed one to hold the pin, and another one to bend it. Note that his example bent the small diameter pins which in the unbent exampes of these adapters are supposed to go into the IC socket into which this module is plugged.

 

I'm very familiar with this type of adapters and they do have issues:

 

- If you plug the large diameter pins into an regular IC socket, the larger diameter overstresses the contact springs in it and then that socket can never again reliably grip a regular IC afterwards. Regular ICs have smaller diameter pins.

 

- If you plug the small diameter pins into a regular IC socket, the socket is not damaged, but these pins are so weak that they easily get bent and then break off when you bend them back.

 

These adapters were used in one of my products in the 1980s which were sold in huge quantitites (10,000's) and consequently we had 100's of returns from customers who broke off a pin. This is why I bought the professional desoldering station I still use today, to be able to repair them. I also had one PCB production run using a new layout where the spacing between the pin rows was wrong and so these "large diameter" pins had to be bent slightly to be able to assemble the product. This did cause some casualties, but still was cheaper than to throw away the whole botched PCB production lot.

 

Based on my experience with these adapters, I don't think that Plamen's approach is optimal yet. The basic idea is good for a one-off specimen, but improvements are needed until these IWM replacement modules could be produced in larger numbers. This may sound nit-picking to you but if you ever engaged in "mass producing" any ready made plug-in modules for any computer, you know what I mean. Unless your workers are slaves who work for food and shelter (sleep under the work benches) you can't allow any such complications which require manual fumbling / mods of sensitive connectors / etc. and drive up assembly/test/repair costs into the stratosphere.

 

Professional assembly houses simply will reject such a project.

 

I think I have some of these adapters around which don't have the large diameter pins but only rows of round, flat surfaces. Maybe these could be reflow soldered flush to the bottom side of a PCB. This would solve the problem with bending the pins. I need to find them in my mess first before I can tell you if these are standard items or were modified by means of a file. Stay tuned !

 

- Uncle Bernie

 

P.S.: I just saw Plamen's post #25 stating that he did not bend these pins because these adapters SMD are standard items. It eludes me why they have the larger diameter pins straight so these must go into a DIL socket. It should be the smaller diameter pins which should be straight and go into the socket. I know for certain because I do have lots of various types of adapters around. All have the smaller diameter pins to go into sockets.

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UncleBernie wrote:If you
UncleBernie wrote:

If you meant a "machined contact" type socket, no, you can't bend those pins, because they will break off.

...

 

No they won't. Bending them once with pliers by 90 degrees does not break them. I have done it many times.

 

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Plamen stated the ones he

Plamen stated the ones he pictured were factory bent.  I've found the square pin headers with bent pins like that (and had to straighten some back out which was really horrible) but I hadn't seen pre-bent DIL sockets before.

 

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softwarejanitor wrote:Plamen
softwarejanitor wrote:

Plamen stated the ones he pictured were factory bent.  I've found the square pin headers with bent pins like that (and had to straighten some back out which was really horrible) but I hadn't seen pre-bent DIL sockets before.

 

 

They are factory bent. DigiKey caries them, but they are all out of stock: click!

This is why I was suggesting for one-offs to use the straight ones from the link in post #27 and bend them manually.

 

This brings me to a general off-topic question that has been bothering me for a while now: would it be possible to make populated SMD PCBs small enough to fit inside an empty ceramic DIP package, so modern chip replacements will look like ceramic retro chips when closed? Maybe one of these types:

 

 

...and if not, at least these:

 

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HDI
CVT wrote:
This brings me to a general off-topic question that has been bothering me for a while now: would it be possible to make populated SMD PCBs small enough to fit inside an empty ceramic DIP package, so modern chip replacements will look like ceramic retro chips when closed?

It may be possible using Chip-Scale Packages (CSP) and very small 0201 passives, but producing circuits that small is very challenging because, for complex circuits, the need to use high aspect ratio connections like microvias. This circuit board technology is called HDI and you can see that the prices for having them made are quite high. Assembly of very small components is also challenging (they blow away if you cough) and the PNP machines must be extra precise which adds yet more cost. 

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Looking at an ESP32 module

Looking at a $4 ESP32 module with the can removed next to an EPROM and it doesn't seem too far-fetched:

 

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On the costs of doing microelectronics assmbly by yourself ...

In post #31, CVT wrote:

 

"... off-topic question that has been bothering me for a while now: would it be possible to make populated SMD PCBs small enough to fit inside an empty ceramic DIP package ..."

 

Uncle Bernie comments:

 

Not so much off topic when seeking a viable IWM replacement. We have a company in town which makes hybrids in small production runs for the local electronics industry (Agilent, Lockheed Martin ...) and they even can take the die (silicon chips) out of existing packaged ICs. The substrate is ceramic with a custom pattern they design so they can do the die attach and the bonding of the ICs. They use very small SMDs for the passives, like bypass capacitors, resistors ... the resistors look like ground pepper, not like bird feed.

 

So it can be done. But the costs are prohibitive. One such hybrid can set you back by several 100's of dollars for small production runs, and the engineering costs adds to it. Below US$ 10k, nothing can be done.

 

For Apple II work this is too expensive. But if Lockheed Martin puts together a rocket to launch satellites and they need some odd IC that was not made anymore since the 1960s then the cost can be justified.

 

Just another example: suppose you have made a few die for one of the elusive Apple custom ICs. You can get them in waffle packs, so they already are separated. Now mount them into a ceramic package. The service companies who do that for you will typically charge $10 per pin. But this includes the ceramic package itself. So your MMU or IOU will cost you $400 each, and the IWM will cost you $240. This does not include the costs to get the silicon.

 

It is cheaper to buy an Apple IIe or IIc off Ebay and cannibalize it.

 

For me, all these little obstacles you encounter in the field of micro electronics if you try to build anything on you own dime was one of the main factors why I decided to work as an employee in the semiconductor industry. With access to the equipment in the company lab you can do a lot of private projects that are financially infeasable if you try to do them on your own dime.  Alone the access to a professional SMD workstation is priceless.  With the micromanipulators and the professional quality stereo microscope you can build really small projects, even with the tiniest components. These workstations are rare and expensive because they are not made in huge numbers. They are only needed for prototype / lab work and are never used for actual production. Much of it is also driven by the desire to keep prototype silicon in house and never send it out to Asian assembly houses. "Ooops - one or two fell to the floor and we could not find them."  --- this is how prototype silicon may end of in the hands of the Communist China industrial spies. It is better to keep all the development work in house until the product is released. Hence, costs for the tools is secondary.

 

- Uncle Bernie

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UncleBernie wrote:Not so much
UncleBernie wrote:

Not so much off topic when seeking a viable IWM replacement. We have a company in town which makes hybrids in small production runs for the local electronics industry (Agilent, Lockheed Martin ...) and they even can take the die (silicon chips) out of existing packaged ICs. The substrate is ceramic with a custom pattern they design so they can do the die attach and the bonding of the ICs. They use very small SMDs for the passives, like bypass capacitors, resistors ... the resistors look like ground pepper, not like bird feed.

...

 

This is when things get really expensive: substrates, bonding etc. I was talking about something much simpler: a tiny PCB that can be produced and populated by a shop like JLCPCB. It will not be bonded, but soldered to the empty ceramic package by the hobbyist. Sort of what Plamen has done, but about half or a third of the size.

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On the diminishing accessability of technology to the hobbyist

In post #35, CVT wrote:

 

" ... but soldered to the empty ceramic package by the hobbyist ... "

 

Uncle Bernie comments:

 

If you can find a source for empty ceramic packages. The prototype assembly service providers I mentioned  have them in stock, I know, but they are  not  inclined to sell them to hobbyists because there is  no money to be made  with that. From the manufactureres of these packages you need to order 1000's.

 

The next obstacle it your proposed soldering process itself. The contact areas on the ceramic package are meant for ultrasonic bonding, not for soldering of any kind. I'm not saying it won't work, because I never tried soldering them, but it will depend on the exact metal layer contruction of these contact areas and on the solder alloy whether it will work or not. The semiconductor industry uses a process similar to soldering in these packages called "Eutectic die attach" (https://mrsisystems.com/eutectic-die-bonding/) and this is not trivial to accomplish in a reliable way.

 

The last but not least issue is the thermal expansion of your PCB compared to the ceramic package. Unless you use some form of interposer, thermal cycles will build mechanical stresses which sooner or later will crack your solder connections. The same problem exists with BGA packages having no plastic film interposer, like the "CSP" flavor of these packages. IMHO you can't build reliable electronics with CSP which will last for a long time. But probably OK for disposable items you throw into the landfill after 1-2 years of use, when the unreplaceable battery is not holding much charge anymore. Such as "smartphones" which, from the standpoint of unwieldy size, vulnerability to damage, high price, and short lifespan are not "smart" at all, except for the profits of their manufacturers. It's also called "landfill economy".

 

The general, fatal, problem with microelectronics roots deeper of course. Unlike with ICs of 50 years ago, leading edge ICs of today are so enormously powerful and so terribly expensive to design (1000's of designer man-years going  into each, they are "systems on silicon") and the single digit nm wafer fabs and supporting backend process machinery are so expensive (billions of US$ invested) that these ICs must be produced and sold by the 100's of millions each year to make the whole industry economically viable. There not all too many products which need this kind of processing power and could be sold in these huge numbers. Smartphones and flat panel TVs are prime examples for such a product. So they must be designed and built in a way they don't last. Otherwise the demand for these leading edge ICs withers away and the whole leading edge semiconductor industry goes bust.

 

There is no way that "hobbyists" can be players anywhere in this league. We will be forever confined to use trailing edge technologies from many decades ago. Until the stocks of these old ICs run out.

 

I'm not saying that trailing edge ICs are not newly made. They are. Actually, the majority of ICs in manufacturing numbers (but not in numbers of transistors produced) are made in trailing edge process technologies. But unlike the 1980s and 1990s, small startups can't access these processes anymore and it also would be tricky to define a novel product which could be made in these trailing edge processes and still could be sold in large numbers and at a profit to make the whole startup viable. Compare that to the "good old days" of the 1980s and 1990s where small, fabless, outfits could design their own full custom ICs and successfully sell them. Nowadays all you can do is to repurpose some mass produced leading edge IC by putting it on a hobbyist friendly PCB and support it with a development software kit. The "Raspberry Pi" phenomenon explained.

 

The key words here are "mass produced" and "repurposed". Only then it's viable to get hobbyist (or small outfit) fingers into the deep submicron IC pie. For those not so familiar with the English language, the meaning of this is that the makers of the pie don't want you to stick your fingers in. It is unwanted / discouraged that the unwashed masses have access to high tech other than as a dumb consumer who just pays for it, but does not know anything about how it works. It's a form of enslavement of the masses to their masters / exploiters. Whereas ability to access technology and bend it according to your own ideas and will and purposes (using it for your own ends  not  endorsed by the rulers) is enpowerment of those who have the brains to do it. This threatens the powers of the ruling parasite class. So they decided to make access to technology prohibitively expensive. And here we are.

 

- Uncle Bernie

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maybe more pedestrian explanations

I think the explanation has some merit, and is confirmed by the direction of education (particularly technical education) over the last 50 years. However, there is a built-in logic to our form of capitalism that causes a continued advancement in semiconductor processes, with the concomitant economies of scale for mass-market digital devices like CPUs. Specialty and analog chips are on the losing side of that shift: many analog designs from yesteryear have had their original processes shut down, and no replica designs in modern processes are possible. So their prices steadily inch upward as the existing stockpiles dwindle.

Look up the AD590MF: this simple temperature sensor only has 8 transistors and was sold for pennies in the 1970s. Today it costs over $300 each, because nobody can make a modern equivalent that meets the same specs. You'll also notice that the majority of the world's stocks of this chip are in Hong Kong and Shenzhen. The Chinese have known about this problem for many years and built up stocks of these obsolete chips while they were still cheap (NRND is the magic word).

Even without malign forces, it's hard to see how it could have happened differently in a capitalist economy. The philosopher Günther Anders wrote that technology has its own imperatives and advances in its own way regardless of people's ideologies. That is obviously controversial, but I think he had a point. Example: once the capital was accumulated to produce large color LCDs, the writing was on the wall for CRT displays. It didn't matter which one was "better" or what people thought about them: in a certain sense, the cathode-ray tube was doomed by the discovery of the thin-film transistor. But in this process, we lose the technological foundations our society was built upon. It's as if in order to build 50 higher floors of the Burj Khalifa, we needed to dynamite the floors at ground level. This is one of the dangers we face if war comes: a sixth horseman no Dürer ever drew. Of course some of the knowledge of advanced technology will survive, hidden in a cave or bunker, but the practical experience and tooling to put it to use will be destroyed or soon run out, as depicted in A Canticle for Liebowitz.

No matter the demographic perils faced by China, their accumulation of decades-old technology and overproduction of mechanical engineers places them in a favorable position if everything goes pear-shaped. Forget about sanded, laser-marked fake chips; have you ever tried to buy a German-made sewing machine or a Japanese-made laser power gauge? You have to go to China to find these items because that's where the factories using this equipment have been for 30 years.

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More on accessability of technology ...

Despite we are a bit deviating from the topic of this thread (replacing the IWM) , 'Robespierre' has brought up some interesting topics in his post #37.

 

As for the "analog IC" topic, I was surprised that nobody can make the  AD590MF  anymore. I think I have a bag full of them in my basement. Will look for them and if I find 100 pcs and can sell them for $300 each, I might have the budget to build an IWM on a real CMOS process ... but this would only yield a few die. Any larger quantity would need much more investment.

 

There are other super cool analog ICs, too. Like this one:

 

https://www.eevblog.com/forum/projects/ltz1000-nice-die-pictures/

 

I can only recommend his website (https://www.richis-lab.de) for everybody  who is interested in the beauty of analog ICs.

 

The problem with the higher performance speciality analog ICs (like this voltage reference, or the even more elusive LTFLU)  is that they were designed by the true giants in the field who learned their tricks of the trade in the 1960s. These analog IC design pioneers not only knew how to design analog integrated circuits but also how to design (or at least tailor) a process technology in such a way that their designs would reach these out-of-the world performance parameters. There is a lot of "secret sauce" involved in every step towards the final product. The circuit designs may look trivial at rthe first glance (few transistors involved) but may have a lot of tricks in it. The layout has tricks in it. The wafer fab process uses tricks which may be hand dialed in for these lots of special parts. The packaging process uses tricks. Such as little "ball bearings" in the die attach compound, to keep mechanical stresses low. Of course, this needs a package with a hollow die cavity. Special alloys for the package and its pins may be involved, also to keep thermocouple effects low. The trim & test procedures may include pre-ageing / burn-in. And so on and so on.

 

And only if everything is done right, at every step, the final product will have the stellar specs no competitor can ever reach.

 

And then the small, boutique IC maker is bought by a larger competitor. The old wafer fabs are closed down and the products are moved to the modern processes of the larger outfit. And then they find out they can't reach the stellar specs anymore. The designers of these rare, super high performance analog ICs have long retired or are long deceased. Nobody knows or understands the tricks which were used. So they can't build these products anymore, even if they wanted. And so these products get discontinued. Pity the customer who needs them and has no replacement in sight.

 

About the 1980s and 1990s

 

In the field of microelectronics, these years were unique. Because small businesses (like me, hint, hint) were able to access cutting edge technologies and ICs like the big guys / aka corporations. And so we could run circles around the big guys, being more agile, and able to access markets which the big dinosaurs could not serve. And we made a lot of money from that. It was even possible, back then, to access CMOS processes which were still the workhorses of the semiconductor industry. Ebeam technology did exist --- ES2 (European Silicon Structures) being just one example. No masks needed - you could make full custom CMOS ICs in a 1P2M technology around 1um (IIRC) in small lots, like 5000 pcs, equivalent to 1 wafer or so.

(https://www.linkedin.com/posts/chrisgare_who-remembers-european-silicon-structures-activity-6970428321339744256-CRuW)

 

Beginning with the mid 1990s all this went away. The 350 nm technology node was too expensive, too  large of a jump, to make for most of the small players. But some services like MOSIS soldiered on and you could get the occasional wafer run on an affordable process. This was great for universities and for prototype runs but as it turned out, all that was viable only for experimental or research work. Once you wanted to make these ICs in useful quantities, it got too expensive too quickly.

 

If you have $50000-$100000 to spend, you can access modern, cutting edge CMOS technologies even today. But all you will get is a a few specimen of your IC in a waffle pack. Forget the idea to ever get these into mass production (unless you want to spend millions of US$). And yet another obstacle, of course, is that with "free" CAD tools like MAGIC you can't design cutting edge ICs, even if the scope is humble in terms of transistor count (no 100's or 1000's of design man years ;-)

 

The reason is that the parasitic extraction tools of these 1980s era CAD suites are too weak to deal with the complexities of deep submicron processes. You need extractors based on field solvers to get it done right. I lost track on what a typical Cadence Composer / Virtuoso CAD seat costs per year in terms of license fees, but IIRC it used to be around $100k per year (Universities get the tools cheaper but can't make products with them).

 

So we are in the inconvenient place we are now (Apple II IC substitution wise). We have to use 30-40 year old PLDs/CPLDs to get anywhere. And we can't make new full custom ICs (although I would be itching to design an Apple IIe on a single IC, low power enough to put it in a wristwatch running on a button cell).

 

Finally, "robespierre" mentioned what would happen if some cataclysmic event would strike our technological civilization. It does not need to be a big event such as global thermonuclear war. I remember one earthquake in Japan which damaged one chemical plant that produced most of the photoresist used by the worldwide semiconductor industry. We were scrambling to do emergency plans which product lines to shut down to stretch the stock of photoresist we had. It was a huge crisis the worldwide public did not hear a peep of. But the Japanese were able to move the production to another, undamaged plant just in time to prevent the shutdown of the whole worldwide semiconductor industry.

 

This is how sensitive this whole Jenga tower of "Hich Tech Industry" has become. Oh, and even the Germans can't produce these great mechanical sewing (or knitting) machines anymore. And even the clever Chinese can't reverse-engineer them well enough to get the same performance from their copies. "Secret Sauce lost " strikes again. (in the early 1990s I designed a few custom ICs for a knittting machine maker, so here you have  one of the hurdles for copycats).

 

- Uncle Bernie

 

 

 

 

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