Are you sure this message comes from the SCSI controller?
Or is it a problem with the IDE configuration in your BIOS?

Good point, let me look a little closer. I will try to get some photos of the screen as well.

Well now it is going to make a fool out of me, I reassembled the machine and it just decided to start working. The only thing I really changed was the location of all the cards in the slots, which I didn't think matters, I also re terminated the scsi cable because it had a nasty twist in it, I suppose there could have been a broken wire.

As soon as it gets through post it immediately starts executing a bunch of stuff, is there a way to prevent that? perhaps then I can get just a basic dos prompt or something?

Try F5, F8 or Shift during boot.

An 8-bit SCSI controller with working BIOS...
That should be matched with an XT, not a 386 😉

An Adaptec 1542CF almost gets maximum out of a UltraPlex 40x max

You were right about the controller error, the bios has an ide hdd configured by default and there was none connected.

How much ram is acceptable for a 386, currently there is 1Mb of extended ram installed and there is room for another bank.

Depends on the cacheable area.
When I have done my calculations right you should have 32 k of cache in 2 banks.
I'm not sure whether it is write back or write through.
In write back mode, my calculations give a cacheable area of 2 MB.
In write trough mode, 4 MB is couvered.

It seems your board works in write through mode, so go with 4 MB.
But a 8 bit SCSI controller won't work good with your 16 bit cache controller which works best with 16 bit access patterns.

Rare C&T chipset and on top of this, even rarer feature, you have a real cache too.

Cheers,

So how does the RAM setup work? There are 4 slots, currently with two sticks installed equaling 1Mb. Is this a case of each module being 8-bit, so two 1MB x 8 modules makes 1MB of ram for the 16-bit bus? or is this two modules each being 512k x 16.

I read that cache is important for 386 performance, not that this is especially fast, it's a 25Mhz 386sx. The system reports 32k external cache, but I don't know where it physically is on the board, there are four 8k x 8 sram chips just to the right of the ram slots, is that it?

Documentation and drivers for the controller can be found here
https://web.archive.org/web/20000621220104fw_ … rmen_index.html
in the Adaptec section.

Alex_03 wrote on 2023-12-12, 02:00:

So how does the RAM setup work? There are 4 slots, currently with two sticks installed equaling 1Mb. Is this a case of each module being 8-bit, so two 1MB x 8 modules makes 1MB of ram for the 16-bit bus? or is this two modules each being 512k x 16.

This is a 386SX, so 32b internal workings but 16b external bus. These 30p SIMMs are 8b wide, so on a 386SX you need to install SIMMs in pairs. However you still add up the size - 2x 1MB modules give you 2MB total. Each pair needs to be identical, but you can mix and match any combination of pairs, up to a maximum total RAM of 16MB (4x 4MB).

Now, if you have 2x 1MB and it's only showing 1MB, it could be a common 286/386SX display issue, where only memory over 1MB is shown. So you have base+hihg+UMB equalling 1MB, and on top of that 1MB extended memory.

CACHECHK or Norton System Inofrmation (or just MEM) shoudl show how much you really have.

I read that cache is important for 386 performance, not that this is especially fast, it's a 25Mhz 386sx. The system reports 32k external cache, but I don't know where it physically is on the board, there are four 8k x 8 sram chips just to the right of the ram slots, is that it?

386SX with cache is extremely uncommon. Four 8kx8 SRAM chips sounds like 32kB of cache. As for how important it is... the 386SX is bottlenecked badly by the 16MB bus, and cache is also on that bus - so I'm not convinced it will help a lot. But the proof of the pudding is in the eating. Test with CACHECHK with cache enabled and disabled.

Lots of useful information there, thanks dionb!

I found 4 unknown 30pin ram sticks that I had laying around, they seem to work just fine and with them installed the system reports 3MB of extended memory. I will check out one of those programs you mentioned and see what information I can glean.

Sounds like you have 4x 1MB and so 4MB total (with 3MB being reported)

I got myself a CF card to IDE adapter as a storage solution for this machine, but the "HDD controller failure" message is back. The card is a 2GB sandisk, and this is the adapter I bought: https://www.amazon.com/dp/B097XS4SXP?psc=1&re … product_details

I used an ideinfo.exe I found on this forum to get the drive details, which I entered into the bios. It gave me 1900 something MB, which seems right but I always get the HDD controller failure message, is this a hardware issue or a setup issue?

Should I create a new topic, since "Help with a scsi HDD" is not really applicable anymore?

2GB is far too much for an original 386SX BIOS, you had 528MB limits back then. I'd suggest using max 256MB CF cards on a system like this.

Not sure that's your only problem, but it's certainly a relevant one.

I figured I may end up doing that, is there a workaround with this card or do I have to purchase a smaller card.

I know sometimes you can format it on a different machine with a 500mB partition, would that work in this case?

Nah, you just can leave the rest unallocated.

The HDD BIOS size limit does not apply to the SCSI disks, because these use the BIOS of the controller instead of the sytem BIOS.
Systen BIOS disk section is usually set to none if using SCSI.
So if the controller supports the 2 GB disk, it will work in the system.
There are other limits partitioning the disk with older versions of DOS, but DOS 6.22 was able to set up 2GB Fat 16 partitions.

Right, I was talking about the compact flash to ide adapter that I bought.

I was able to get the CF card working the other day, I formatted the disk to a 500mB fat partition, but I think the ultimate issue was the fact that I had the cable backwards on the motherboard, since it is just a 50pin header. I though I had it right the first time, but apparently not.

I don't know what I am going to do with the scsi drive, perhaps I will put it in the XT machine that my brother has...
When I work on this computer in the near future, I will probably start a new topic since the scsi hard drive is not my focus anymore.