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IDE to SCSI Adapter - discrete logic - reverse engineering candidate?

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I've started trying to identify the components on the IDE Zip250 to SCSI adapter board on a very interesting Winstation product: WFS2E1W13. The board appears to be a discrete component IDE to SCSI bridge implementation that could be equivalent to the ASIC on ACARD adapters?

 

Assumption would be that some of the ICs must be programmable logic, but the board might be a good model for development. Programmable logic IC could be dead ends, but where they fall in the schematic might define the underlying architecture. If anyone recognizes any of the ICs offhand, please post them.

 

Major ICs:

U2 - What should be a stickered ROM

U25 - qlogic - FAS209 - SCSI 10MB/s SE 8bit

U5 - Intel - S0C31BHI - ????? - appears to be a stock part equivalent to same part number from Mfr. TMS - anybody have info on that company or the chip's function? Searching came up dry so far.

 

Thinking here is that  this could be a first step in creating a SATA to SCSI board? SATA to PATA chips seem readily available or if not, could be easily harvested from very inexpensive adapters.

 

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This is so far out of my league as to be ridiculous, but someone might take an interest?

 

Edited by Trash80toHP_Mini

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Neat, I didn't realize someone built SCSI Internal Zips (Iomega built SCSI Externals) - it looks like this is probably the same configuration used by the Winstation internal LS-120 drive, which was similarly an Imation LS-120 drive, with an IDE-SCSI board tacked on.

 

Adapters to use SATA disks on SCSI buses already exists, Acard built them. For example: http://www.acard.com/index.files/Page861.htm

 

EDIT: Here's a more generic listing of Acard's SCSI bridges: http://www.acard.com/index.files/Page385.htm /EDIT

 

And: https://www.ebay.com/itm/ACARD-ARS-2320-Ultra320-SCSI-to-SATA-2-Enclosure-68-pins-New-Old-Stock-Tested/274033010323 (You could enclose a 2.5" SATA disk in this adapter and put it in a server where you'd use a u160/u320 scsi drive.)

 

It would be interesting to get a perspective on whether cloning the Classic Mac OS compatible SATA cards would be easier or more difficult than this, because most Macs that really "need" more speed than their onboard SCSI have PCI slots. The rest of them are using IDE, and IDE-SATA/CF/SD adapters do exist.

 

The other main option here is SCSI2SD v6 and in my experience doing day-to-day stuff on an 8600/300 with OS 9.1 and a scsi2SDv6, that's a very good solution if you did not have a pci slot or SATA card for some reason.

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Yep, but everything ACARD seems very expensive. Adapters have hit the market at very reasonable price points, but ISTR they were determined to be for the likes of opticals, not mass storage?

 

LVD SCSI to IDE adapters are in the $70 range on Amazon.

 

867167569_ACARDIDEtoLVD-SCSIAdapter.thumb.jpg.cb4876475728d725a406a57979d9fe02.jpg

 

I'm wondering if something more compatible with Mac cubic might be designed or even with EMMC storage on a board built in the 2.5" PowerBook form factor? ISTR, you saying SCSI2SD is great for snappiness of response times, but throughput pales as compared to CF or even spinning rust?

 

Dunno, it's all theoretical discussion for now and probably too much work to do for benefit, but very cool if workable.

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The Intel chip could be something like an 80C31BH MCU.

If it is then it has no internal program memory and relies on an external source for its program memory. This would make copying easy.

 

Edited by Bolle

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Would that be supplied in ROM for the program or in discrete memory for buffer? The board's design use as 250MB Zip interface or LS1io as Cory suggested would be cool. Interfacing faster ATAPI cds and even DVD in SCSI only or Limited function, single drive only IDE Macs would be interesting applications.

 

Interfacing EMMC in a laptop drive form factor I find interesting. EMMC would be better than SD or CF, if not a bona fide SATA SSD no?

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44 minutes ago, Bolle said:

The Intel chip could be something like an 80C31BH MCU.

If it is then it has no internal program memory and relies on an external source for its program memory. This would make copying easy.

That chip with the "SLS/7.43" sticker has 28 pins, which does indeed make it a good candidate for being the ROM.

 

I haven't read the label on every chip but every one I have looked at seems to be a generic 74xx series part, so there may well be no programmable logic on this thing besides the CPU. I'm going to demur on whether this is actually a useful thing to try to clone; it has a pretty high part count and the availability of the SCSI chip is probably a significant issue. (I see one guy selling a box of 11 of them on eBay. One guy. That's not a good sign.)

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ACARD uses a custom chip to make their adapters simple and cheap to build. The older adapters used more chips and space, plus those chips are probably not availbale these days.

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1 hour ago, Trash80toHP_Mini said:

STR, you saying SCSI2SD is great for snappiness of response times, but throughput pales as compared to CF or even spinning rust?

It depends on the machine and what you're doing.

 

In my experience, SCSI2SDv6 is just about fast enough to be used for something like video capture on the 8500/8600 (which is reputed to need about 4.5 megabytes/second of transfer.)

 

This is the post with my MacBench 4 disk benchmark results:

So like, it was good enough for booting and running applications and probably even dev work would be fine on it, but, and I haven't tried this, it might not meet expectation if you started throwing video at it.

 

At that point, yes, something like a real hard disk would be better, or something on SCSI with a better adapter.

 

The use cases for that are moderately niche, however, and if you're setting up an 8600 for retro analog standard def desktop video editing, you're probably also hunting for period-appropriate bits like a Micropolis disk or a Seagate Elite 9/23/47 for capture, for example.

 

 

1 hour ago, Trash80toHP_Mini said:

but ISTR they were determined to be for the likes of opticals, not mass storage?

There are different adapters with different purposes, though, to be honest, what with the utter glut of cheap-good IDE and SATA CD-ROM drives that exist, someone would do well to pick up a couple of those adapters if they're cheap and integrate a few into, say, ex-syquest external enclosures -- if the inventory of external SCSI CD-ROM drives was at some point drying up.

 

There's also the CF powermonster, which might be a design that can be put back into production, and would provide a performance boost and modern part, but those were selling for more than SCSI2SDs even years ago when SCSI2SD cost a lot more than it does now and the powermonster (aztecmonster?) was still being built.

 

49 minutes ago, Trash80toHP_Mini said:

EMMC would be better than SD or CF, if not a bona fide SATA SSD no?

eMMC is usually very similar media to SD. I wouldn't say it's any better, but SD is a super stratified market at this point, as I keep mentioning all over the place every single time someone says their SCSI2SD isn't as fast as some people say it is -- that's always because they bought an SD card that's not high end enough.

 

eMMC itself runs the gamut from "run away as far as possible" to "passable, but you'd absolutely rather have SATA or NVMe".

 

1 hour ago, Trash80toHP_Mini said:

I'm wondering if something more compatible with Mac cubic might be designed or even with EMMC storage on a board built in the 2.5" PowerBook form factor?

PowerBooks are an entirely different use case. Out-and-out highest end possible raw performance really isn't what anyone needs strictly speaking to use all the functionality of any SCSI-having PowerBook. (Notably here, the PowerPC PowerBooks all use IDE, for which known good and widely available m.2 and CF adapters are available.)

 

Anyway, for SCSI PowerBooks, there's the SCSI2SD PowerBook Edition: https://store.inertialcomputing.com/product-p/scsi2sd-v5-2.5-inch.htm 

 

And the regular SCSI2SD devices all fit within the boundaries of a 3.5-inch disk, meaning they fit fine in any 68k Mac.

 

So, like, I'm not against the idea of another kind of adapter existing, but, I do think we should think about what our needs are and what is/isn't available and how it does/doesn't work.

 

I'll admit, aside from perhaps "really fast NuBus PowerPC Macs" I struggle to think of a scenario we don't have reasonably covered, although perhaps some of our wiki documentation needs to be updated.

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Re: the performance discussion, it bears pointing out that the adapter in the OP is almost certainly *far* slower than an Acard-style adapter, and very likely significantly slower than the better variants of the SCSI2SD. It's based on an 8-bit MCU designed in 1980 as a competitor for devices like the Z-8. It's clocked pretty high for an 8 bit CPU (... of the era, not now) but it doesn't look like there's any external RAM, which would almost certainly rule out DMA operation. An 8-bit MCU with a very small amount of RAM task-switching between doing PIO with that SCSI chip and driving the IDE bus is anything *but* a recipe for high-speed operation. Color me surprised if this thing could keep up with even the fairly mediocre performance of the ZIP 250 drive it was connected to.

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Like I said, could be more bother than it's worth, but interesting discussion nonetheless. Is there a soft(?) SCSI controller design available for  integrating into an FPGA? That's seems like part of what's going on in ACARD's adaptation. Fast/Wide UltraSCSI would be optimal and even faster than Fast/Narrow of SCSI2SD v.6, which I can't wait to get my hands on at some point, BTW. :approve:

 

2 hours ago, Unknown_K said:

ACARD uses a custom chip to make their adapters simple and cheap to build. The older adapters used more chips and space, plus those chips are probably not availbale these days.

Yep, mentioned ACARD's ASIC based implementation in the first sentence of the post. I was looking at this more as a possible block diagram for implementing an updated version in FPGA.

 

1 hour ago, Cory5412 said:

There are different adapters with different purposes, though, to be honest, what with the utter glut of cheap-good IDE and SATA CD-ROM drives that exist, someone would do well to pick up a couple of those adapters if they're cheap and integrate a few into, say, ex-syquest external enclosures -- if the inventory of external SCSI CD-ROM drives was at some point drying up.

I'm interested in adapting modern slot loading opticals from laptops. ATM I've got them set up with IDE adapters, but having one adapted to SCSI is one of my goals.

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1 hour ago, Trash80toHP_Mini said:

Yep, mentioned ACARD's ASIC based implementation in the first sentence of the post. I was looking at this more as a possible block diagram for implementing an updated version in FPGA.

I'm sure whoever owns ACARD's intellectual property at this point isn't particularly interested in sharing. Their old marketing spiel says their converter ASICs had a built in "High Speed ACARD RISC Microprocessor" on it, what the actual specs of what that is are and whether it used an ISA that has FPGA implementations openly available are utter unknowns to me. (Although perhaps you might be able to figure it out by analyzing a firmware file. For cheap thrills I downloaded one and ran "strings" on it; it looks like it has the SCSI ID text fields in plain text so it might not be encrypted in any way, so if you could make an educated guess what the instruction set is and could run a disassembler program on it in principle you could learn a lot about its internal architecture. Those are really big ifs, though. It's not unusual for ASIC-embedded CPUs to use highly customized ISAs; it might be derived from, say, MIPS, but contains weirdness in it that renders it cryptic without the customized support toolchain.)

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That's waaaay beyond my ken. :blink: I knew Bolle would find this interesting and I was hoping folks like you, @trag and the FPGA/CPLD (whatever, they're just acronyms to me) gunslingers might be interested, if only on a theoretical level. Never considered ACARD sharing anything, I was wondering if on open source SCSI controller was out there?

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I do kind of wonder what the difference between the IDE and PATA SCSI adapters are outside of just firmware. If somebody could crack that then the much cheaper PATA adapters could be reflashed and make life easier.

 

Also the Addonics adapters I have seem to be the same as the Acard variety of the same model name and firmware.

 

100_1283.jpg

Edited by Unknown_K

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14 minutes ago, Trash80toHP_Mini said:

I was wondering if on open source SCSI controller was out there?

There's this project from 2008 on OpenCores that was active for a week and a half before they suspended it. That's not too promising.

https://opencores.org/projects/scsi_chip

 

That said, there are plenty of software bit-banging solutions out there for doing SCSI with just some buffers. (There's SCSI2SD, that project for doing it with the GPIO ports on a Raspberry Pi, etc.) An FPGA god probably wouldn't have a *lot* of trouble converting the code that drives those buffers into hardware state machines. It's just a lot of picky, excruciating work for someone to do out of the goodness of their heart. And the end result would probably have to sell for a *lot* more than a SCSI2SD sells for if you want something *fast* and "production quality". (Based on several projects I'm vaguely interested in having it looks to me like the minimum ballpark price for a complex FPGA "hobby" project is in the $100-$200 range. That's a lot to hook up an old IDE CD-ROM drive.)

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I think most of the ATAPI models were for old SCSI only systems where people wanted to replace the dead SCSI CDROM drive with something more easily available like an IDE CDROM, CDRW, or DVD drive or burner. 

 

I stuck a DVD drive into a Q950 for fun and it worked from what I recall (connected to a Jackhammer card).

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16 hours ago, Gorgonops said:
17 hours ago, Trash80toHP_Mini said:

I was wondering if on open source SCSI controller was out there?

There's this project from 2008 on OpenCores that was active for a week and a half before they suspended it. That's not too promising.

- Synchronous Data Transfers un to 4MB/sec is even less promising. That would be more on the order of pathetic Macintosh SCSI 1 implementations?

 

17 hours ago, Unknown_K said:

I do kind of wonder what the difference between the IDE and PATA SCSI adapters are outside of just firmware. If somebody could crack that then the much cheaper PATA adapters could be reflashed and make life easier.

 

Also the Addonics adapters I have seem to be the same as the Acard variety of the same model name and firmware.

 

100_1283.jpg

Edited 15 hours ago by Unknown_K

 

Addonics appears to have distributed a 96k modem for PC from the OEM(?) that made my PowerBook specific 56k modem. Same very cool case, compatible with the 56k modem's ADB PTO, PowerBook Charcoal and all. I'd be very surprised that you'd find anything but an Acard logo under that Addonics sticker.

 

Model number "7722" between Addonics and Acard is nearly the same, but the LF suffix combined with LVD spec on the IBM aCard IDE to LVD-SCSi Bridge Adapter AEC-7722 give me pause. Have you got the SCSI Spec on yours? LVD was introduced in Ultra-2 which appears to be compatible with LVD 1.2 and HVD ≥5 voltages while Ultra3 appears to be LVD 1.2 only. What's the date on your adapter? 1994 to 1996 would be Ultra-2. I wonder about the IBM/Acard version dates, if made after 1996 it could very likely be Ultra-3 and low voltage only and so incompatible for my purposes? Wondering here about pre-1996 Mac voltage compatibility and optional G4 series SCSI card?

 

Wikipedia

Quote

Ultra-2
This standard was introduced c. 1997 and featured a low-voltage differential (LVD) bus. For this reason ultra-2 is sometimes referred to as LVD SCSI. LVD's greater resistance to noise allowed a maximum bus cable length of 12 meters. At the same time, the data transfer rate was increased to 80 MB/s. Mixing earlier single-ended devices (SE) and Ultra-2 devices on the same bus is possible but connecting only a single SE device forces the whole bus to single-ended mode with all its limitations, including transfer speed. Ultra-2 SCSI actually had a relatively short lifespan, as it was soon superseded by Ultra-3 (Ultra-160) SCSI.


Ultra-2
Also known as Ultra-160 SCSI and introduced toward the end of 1999, this version was basically an improvement on the ultra-2 standard, in that the transfer rate was doubled once more to 160 MB/s by the use of double transition clocking. Ultra-160 SCSI offered new features like cyclic redundancy check (CRC), an error correcting process, and domain validation, a way to negotiate maximum performance for each device on the chain.

 

Curiouser and curiouser. Got linkage to the less expensive "PATA" adapters? What was the acronym for IDE with optical drive support? Drawing a blank again. :mellow:

 

 

 

 

Edited by Trash80toHP_Mini

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HAH! makes sense. That's too bad, good for single device only "chain" for all practical purposes in a Mac w/CD then? I guess you could use the Optical Adapter (ATAPI) with it. Dunno about flashing the BIOS, but some SMD rework could test your hypothesis. I imagine reading the ROM/BIOS in a bare nekkid state and making copies might be a good way to go. Methinks you're right, different BIOS for low level product differentiation? Sticker peeling and ASIC ID check would have to be the first step. A slower version of the ASIC would be a better way of differentiating product levels. Could also be a fuse burn in the same part as Moto disabled failed test FPU sections to create perfectly good LC040 versions along with intentional disabling for product level differentiation.

 

just missed edit window: was correcting the second Ultra-2 to Ultra-3 and the dates to 1996 and late 1997 when the hourglass flipped. Also found ATAPI acronym in the description on your box. [:I]

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3 hours ago, Trash80toHP_Mini said:

- Synchronous Data Transfers un to 4MB/sec is even less promising. That would be more on the order of pathetic Macintosh SCSI 1 implementations? 

Let the record show that 4MB/second is the equivalent of a 26.6666x-speed CD-ROM drive. Why do you need something super-fast if your goal is to drive laptop PATA CD-ROM drives, again?

 

(Sure, that is only about 3x if you're using DVD as your benchmark but, still, it's fast enough.)

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It's an interesting project, but I'm not getting emotionally invested in any new ideas, until I actually complete some old ones.   I'm mostly focusing on making a living these days.    It's going well, but takes a lot time.  I'm working for Roku and we just got the new 4K TV models to market.   Summer was bussssssssssseeeeeeeeeeeeeeeeeeeeeeeeeee.

 

As I understand it, Acard's converter cards contain a custom processor of some sort.    It may be a variant on an existing architecture, or it could be something their designers built from scratch.     If the latter, reading out hte attached ROM isn't likely to mean much.   It's probably full of object code for their custom processor.

 

I'm also not htat convinced that some of their products are ATAPI only or disk only.    The ones I've tried work great for both, and I don't see why they'd go to the work to reengineer it to remove abilties.   But I'm happy to read actual test results that prove me wrong.

 

My guess is they have one basic adapter design and they've been tacking on different SCSI/PATA/SATA protocols as necessary.

 

I have a book at home titled something like, The IDE and SCSI Protocols.   Looking at the command sets, I think Gorgonops is right a few posts up.  It's mostly goign to take the tedious work of going through and translating, with probably a few corner cases and special cases where things just don't translate easily or require additional/special handling.

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7 hours ago, Gorgonops said:

Let the record show that 4MB/second is the equivalent of a 26.6666x-speed CD-ROM drive. Why do you need something super-fast if your goal is to drive laptop PATA CD-ROM drives, again?

OP was about developing something better than SCSI2SD in terms of throughput using IDE SSDs or IDE adapted SATA SSDs or something like that. Using a laptop slotloader in a SCSI Mac is but a side issue. 4MB/second is about what, Mac II to Quadra era SCSI on the Mac?

 

 

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Those Adtron SCSI-to-CF adapters used an AMD Am186 combined with an off the shelf NCR SCSI chip, some RAM, and a ROM. Basically a x86 PC with SCSI acting as a bridge for the IDE device. It was common to do that before FPGAs became cheap/fast enough to do the job.

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11 hours ago, Trash80toHP_Mini said:

4MB/second is about what, Mac II to Quadra era SCSI on the Mac?

Think more: "Plus through Beige G3" - at least if you believe Wikipedia's PowerMac G3 page, about the db25 SCSI connector.

 

Some of the 7000/8000/9000 era machines had a secondary 10MB/sec SCSI channel. It's possible the Beige had two buses as well, but without the internal connector for the "slow" SCSI bus.

 

Point being, that performance should be "fine" for most things where SCSI is your only option (68k, NuBus PPC).

 

I'm not entirely convinced that there's something big we're missing out on here in terms of fast SCSI emulation/adaptors.

 

Every PCI Mac where it's even remotely important has good support for the SIL3112 SATA cards, and other IDE cards, for which there are SATA adapters that are cheap, plentiful, and known working, and for every non-PCI Mac or PowerBook there's typically other solutions that are Good Enough for that system.

 

This is an extremely well-solved problem, on the Mac.

 

There are a handful of late surviving RISC UNIX platforms where this is still a problem, and I think that those crowds are just forking over the money for acard adapters, or using SAS HBAs and external disk boxes.

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Slow compacts don't need fast SCSI HDs and as Cory said anything with a PCI slot has cheap and easy solutions for larger faster HDs (80/160 SCSI cards, SATA cards, or for the Beige G3 SATA to IDE adapters). I even shelled out a few bucks for a UWSCSI 320 PCIE card for one of my G5 towers.

 

What really needs a better solution would be Nubus equipped 68040 and early PPC desktop/towers. To get past the slow built in SCSI bus you need a ATTO SEIV (if you don't need it to be bootable) or a FWB Jackhammer and prices for those cards are much more expensive then a IDE to SCSI adapter. What would be cool is a small custom made Nubus card (assuming you can find the Nubus connector cheap enough in quantity) with a SATA interface to either a cheap SATA hard drive or smallish SATA SSD both of which are being discarded in the millions now for larger and faster SSD drives in laptops. You can either make the card small with 2 SATA ports or larger with board area to mount a laptop drive with a second connector for a full sized SATA drive mounted in the case. If you can make one for less then the price of a Jackhammer goes for it will sell.

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1 hour ago, Cory5412 said:

It's possible the Beige had two buses as well, but without the internal connector for the "slow" SCSI bus.

I'm fairly certain the Beige only has the *slow* bus. Unlike some of the bigger Beige PPC iron the internal and external connector are on the same chain (like a Quadra or older class machine), and that means the MESH integrated to the Heathrow ASIC is limited to 5MB/s.

Honestly I don't think there's really much future in SCSI-to-"a real device" adaptation. If you really need a high-speed solution and are a little patient you can get one of those ACARD adapters for optimistically what a truly high-speed remake would cost, and coming in right around the prices of those devices are things like the SCSI2SDv6 that are getting into the same speed ballpark as "pretty decent" contemporary-to-the-machine drives. I understand that, yes, there *are* people (literally dozens of them, maybe?) still doing things like video capture and whatnot on that original hardware, but for almost anyone else who just wants to use a machine of that vintage for "retro fun" SCSI2SD-style solutions are performant enough. Is the real audience for "blazing fast, way faster than the original!" drive performance for 1993 vintage machines really big enough to need a new-build device to fill it?

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