Ah, I guess simple solution is SCSI2SD by Michael McMaster: https://www.codesrc.com/mediawiki/index.php?title=SCSI2SD and use SD card instead of SSD.

Afaik SAS controllers support the use of SATA drives but old (parallel) SCSI controllers don't support SATA drives and SATA drives don't support old (parallel) SCSI controllers.
This means you can't just connect a SATA drive to an old (parallel) SCSI controller using a 'dumb' adaptor cable I'm afraid.

What do you mean by "ISA VLB"?

ISA and VLB are very different beasts, and 386 VLB incredibly rare (basically only a handful of 386.486 hybrid boards and some exotic SLC/DLC things). 386 was stuck with ISA, EISA (and MCA in rare instances), and I/O performance was limited by those buses. 486 had VLB and PCI (as well as ISA, EISA and MCA), but very early versions of both, resulting in high CPU usage.

No one uses SCSI on such systems for its performance, only for period-correctness. So breaking that by going with SAS, when you could get equal performance out of a decent IDE card with IDE-CF adapter, is pretty pointless.

Also consider that 'performance' is many metrics, but that 'feeling fast' is 99% down to latency, not throughput, and that eliminating drive seek time by using something (anything) solid state is the best way to improve that. A cheap CF card beats an expensive SAS drive, even if you could get it to work (which I doubt).

An EISA Adaptec 2740W or 2742W easily outperforms any onboard IDE controller of modern 486 boards.
18 MB/s busmaster performance is much better than any PIO you could achieve with IDE interfaces.

Oh, I know some 386 had VLB. I'm looking now and only my 486 has VLB. The 386 motherboard has ISA only. So I guess even ISA SCSI controller like Adaptec AHA-1520 with SD card connected via SCSI natively will not be much better. Right now I have ISA IDE controller (the 386 does not feature its own onboard IDE controller) and I plan to put SD card over IDE. I was just asking from nerd scientific purposes if ISA SCSI could squeeze more megabytes per second. Mainly for unzipping / ethernet ISA / CD-ROM over IDE or SCSI.

I think it makes sense if you have VLB SCSI or PCI SCSI. But ISA SCSI seems not useful. Also my motherboard has both PCI and VLB (486), so I think PCI SCSI would be better here. VLB SCSI might be useful only for 486 board without PCI.

Disruptor wrote on 2021-06-29, 16:08:

An EISA Adaptec 2740W or 2742W easily outperforms any onboard IDE controller of modern 486 boards.
18 MB/s busmaster performance is much better than any PIO you could achieve with IDE interfaces.

Ok, thank you. I don't have EISA though. Only ISA and/or VLB.

Currently I use CF card IDE adapter and it runs FreeDOS with XT-IDE bios nicely.

Same on my ISA 386sx/20.
The ISA Adaptec 1542B outperforms the IDE adapters I've tried on that system.
Busmaster is the keyword.

Disruptor wrote on 2021-06-29, 16:54:

Same on my ISA 386sx/20.
The ISA Adaptec 1542B outperforms the IDE adapters I've tried on that system.
Busmaster is the keyword.

WOW! Okay, getting Busmaster now 😀

If you want to mess around with SCSI, you can also try with an SCA 80 pin HDD ( which can be bought for cheap as there seems to be plenty available second-hand) and plug it to your ISA SCSI card with the help of an adapter.

It may or may not work 😅

The key with the busmaster transfers is that the main processor could so something else while data is transferred from disk to memory or vice versa.
However, this requires a multitasking operating system. You won't see much improvement on DOS.
Yes there are some PCI IDE or even SATA controllers. Some of them may not work in a 486 due to old PCI version, Pentium commands in BIOS, ACPI calls or something else. You may try. On VLB it is even more difficult. There are Adaptec 2840VL and 2842VL. But it may happen that your VLB board is incompatible to your busmaster controller. And it may happen that busmaster controllers do not run in every slot - you have to try.

I've upgraded my 386sx/20:

Original configuration
8 MB RAM
IDE controller
520 MB IDE disk (capped to 504 MB) (PIO 3)
ISA ET4000 AX

New configuration
20 MB RAM (4 MB EMS which is only usable under DOS)
Adaptec 1542B
1 GB SCSI disk
ISA ET4000 W32

I know a 386sx is a kind of torture under Windows 95, but with a GUI accelerator and a busmaster storage controller it became a little beast!

Disruptor wrote on 2021-06-29, 19:06:

The key with the busmaster transfers is that the main processor could so something else while data is transferred from disk to m […]
Show full quote

The key with the busmaster transfers is that the main processor could so something else while data is transferred from disk to memory or vice versa.
However, this requires a multitasking operating system. You won't see much improvement on DOS.
Yes there are some PCI IDE or even SATA controllers. Some of them may not work in a 486 due to old PCI version, Pentium commands in BIOS, ACPI calls or something else. You may try. On VLB it is even more difficult. There are Adaptec 2840VL and 2842VL. But it may happen that your VLB board is incompatible to your busmaster controller. And it may happen that busmaster controllers do not run in every slot - you have to try.

I've upgraded my 386sx/20:

Original configuration
8 MB RAM
IDE controller
520 MB IDE disk (capped to 504 MB) (PIO 3)
ISA ET4000 AX

New configuration
20 MB RAM (4 MB EMS which is only usable under DOS)
Adaptec 1542B
1 GB SCSI disk
ISA ET4000 W32

I know a 386sx is a kind of torture under Windows 95, but with a GUI accelerator and a busmaster storage controller it became a little beast!

Nice! You have my respect and I adore you, haha. Yes, I love the 386 for old games like Gunboat. They are better playable than on 486 (even with turbo off). So I want to push the I/O operations throughput to max, but keep the CPU cycles original.

Mine is 386DX-40 + coprocessor and it came preinstalled with Win95 and CD-Rom (connected to Sound Card). It is currently my favourite machine for DOS gaming. I win it in some auction locally and it was a company computer (that's why Win95).

I have also ISA ET4000 W32, but it has some compatibility issues. For example in Chaos Engine it does not work. Even in SETUP I switch from VGA to TSENG (they have some fix) and it does not work. It originally came with Trident 1MB ISA, but I could see some ghost 5px x 5px semi transparent mosaic (maybe reflow framebuffer like 3dfx haha). So I bought Octec AVGA-20 (Cirrus Logic) and now everything works perfectly. It came with 512kb only, but I have stolen the 256kb 60ns memory from Trident and now it has 1MB as well.

I upgraded with ZIP 250 MB and FlashFloppy USB emulator (GoTEK mod). I will upgrade more, perhaps SCSI. Right now I have GSI Model 21 IDE controller, which supports 4 floppy drives and 2 IDE drives. But in the end I might not need it for this machine because I bought 5.25'' + 3.5'' floppy combo drive. The plan now is to put ISA ethernet with XT IDE (ready to go) and I need to partition 32GB SD, so it can run DOS 6.22 + Win95 + FreeDOS. Mainly for experimenting with software and fixing compatibility issues on the go.

Cherry on top will be ISA USB card (found on AliExpress) and I will upgrade this 386 to WiFi, hehe. There is Ethernet RJ-45 to Wifi bridge. So you can "wifilize" any ethernet device and even 286 can have Wifi 😁. I found also ISA EIDE controller, which should provide faster speeds.

These are my upcoming upgrades:
1) https://www.ebay.com/itm/114861659090 (must have 386 sticker for chassis hehe)
2) https://www.ebay.com/itm/274813297018
3) https://www.ebay.com/itm/184367485595

Cherries on top:
- Teensy controller for active USB HID to AT DIN (I'm running Ajazz K510 retro styled modern USB RGB mechanical keyboard)
- OSSC VGA scanliner to HDMI connected to Samsung QLED TV (the side effect is that you are able to connect Bluetooth headset to TV and have wireless audio)
- FreeDOS has a lot of new drivers that makes it possible to use different hardware easily (networking features, FAT32, HX RT DOS Extender can run simple Win32 apps - need to test it)

Well, I had strange problems with my ISA ET4000 W32 too.
I had to change a jumper's position to fix the problems with the Windows 3.x and Windows 95 drivers.

Disruptor wrote on 2021-06-30, 06:56:

Well, I had strange problems with my ISA ET4000 W32 too.
I had to change a jumper's position to fix the problems with the Windows 3.x and Windows 95 drivers.

Interesting. I did notice the jumpers, but could not find out what is it for. Do you have some documentation? What position is working for you? I tried some random combo and no luck so far.

Can you post a picture of your card please?

Disruptor wrote on 2021-06-30, 18:17:

Can you post a picture of your card please?

Here it is

Do you have it in full size too?

Disruptor wrote on 2021-07-01, 17:38:

Do you have it in full size too?

Full size here

PCB on back says Machspeed 9424

Disruptor's card looks like this:

JP1 interrupts the 0WS line is open, so obviously: JP1 installed: 0WS, JP1 open: default wait states.

JP2 connects pin 26 of the ET4000/W32 to either +5V or GND. I can't find the ET4000/W32 datasheet online. The ET4000/W32i datasheet doesn't list any function of pin 26 in ISA mode, so that datasheet isn't helpful. The card works as ET4000/W32 in Windows only with the jumper on the two pins away from the ET4000/W32 chip, as shown on the picture. If I remember correctly, that position grounds pin 26.

cyberluke wrote on 2021-06-29, 15:06:

Hi, can you get some SAS SCSI cable with SATA connectors and use it on SOME controller for ISA VLB or PCI? I read that SAS SCSI use SCSI command set, but I don't know if it is compatible with old parallel SCSI or if there is some adapter or some retro controller with different connector.

The goal is: skip slow IDE controller on 386 and 486. Use SCSI ISA VLB (386) or SCSI PCI (486) or on-board SCSI (dual pentium 3) and connect SATA drive (normal or SSD) directly to SCSI. Which should be faster than built in non-UDMA ATA IDE controller.

Someone could create this retro ISA VLB SCSI card with some of the many SAS cable variations.

Ok this is a lot to unpack.

In order: Absolutely not & it is NOT compatible*.

Here are the GO-TO controllers for each bus:
ISA - AHA-1542 (options vary, with and w/o floppy)
VLB -AHA-2842A (options vary, with and w/o floppy)
PCI - just go with a cheap SATA2 card and a small SSD

You are not going to overcome bus limitations with scsi. Truth be told SCSI is not user friendly. It has at least 100 minor pitfalls when it comes to SCSI and the layperson should avoid it. That said, I love it and use it often. For ISA/VLB anyway. Once you have the option for sata, that should be the only choice. Its CHEAP, fast, and easy. Like my ex.

*TECHNICALLY adapters exist to allow sata and ide drives on the scsi bus. They usually cost more than a mortgage payment. Its never worth it. that said, SD/SCSI adapters are relatively cheap are great for classic macs!