Terminating cheapo SCA -> 50Pin SCSI adapters

[max1zzz]

Yeah, it is really just the luck of the draw weather a drive requires extra termination. For ones that don't there is no need to add the extra 8 resistors.

Using inline terminators was what i originally intended to to, however i decided just to see if i could just add the termination to the board.

However i guess the real use of these is not so much for the termination, but to allow some more picky drives to be used

 

[Bunsen]

Awesome work.

 

[max1zzz]

Thanks

I shall be makeing a few of these if any members are interested, £4.50 + whatever the shipping is.

 

[max1zzz]

finally got a working BD0366459B (first was bad, second i think got damaged in transit) i can confirm that terminating the extra lines made all the difference, without doing it the drive is not seen in anything but with it the drive works fine

 

[Trash80toHP_Mini]

Great R&D on the wide side termination issue, comrade. :approve:

 

[max1zzz]

thanks

Tbh it was less of research and more of just probing a dead hdd to find out how it was terminated, and then a little guesswork

Hopefully this will allow a much wider range of drives to be used in these old macs, i'm planning to buy a random sample of whats on ebay and see which work

 

[Trash80toHP_Mini]

That pretty much sums up the definition of R&D to me!

 

[max1zzz]

Your right there actually, I guess I can call it R&D then

Also, anyone else have a recommendation of a picky drive I should try next? If not I'll just grab the first sub £10 sca drive my next eBay search brings up (actually I did find a lot of 5 36gb sca's for a little over £20, very tempting...)

 

[max1zzz]

Got a new drive today, and it has a interesting feature, it can be set to narrow or wide mode...

in wide mode it needs the extra lines terminated, but in narrow mode it dosen't

the drive is a 9.1gb 7k2 rpm compaq bb009135b4 (or a fujitsu mah3091mc - it is the same drive) i wonder if this is common on ultra 2 drives?

(i must add i haven't tried it on a 68k yet, just on the g4 qs, but i don't see why it wouldn't work)

 

[uniserver]

but i don't see why it wouldn't work)

try it first.

before you say this.

 

[Paralel]

I have to disagree with you, Uni. There's no problem with forming a theory and sharing it. It's not as though he said it worked when he hadn't tested it. Hopefully he will test it and share the results.

We're all here to learn, as well as help, one another; share knowledge, experience, and theory, no?

 

[max1zzz]

yeah it works



I do understand what uniserver said - these macs can be picky

my assumption was because this drive had a setting to set weather the drive was on a narrow or wide bus

they do seem to be much less picky with all the lines terminated though, i plan to continue testing random drives like this

 

[uniserver]

Not trying to poke at anyone, Its just, this is not in the lounge, and wouldn't want a ton of people to flock to ebay and buy up hd's only for them to not work.

thats all.

For sure these terminating adaptors he is making are very awesome! They will save people time and money.

and not to mention his solution is more compact/integrated then any other solution out there.

There was a nice solution OWC was selling, but not any more. This solution is next best inline!

So to conclude, For people that might come across this,

There are some SCSI hard drives out there that will work good in Vintage Macs, (with this adaptor he is selling)

We need to make a thread that has a standard format, with a photo of the Hard drive that works, then specifications of it. Maybe with current price per.

Obviously cheaper is better Great Availability is also pretty nice too

Also when in doubt, one could purchase a working scsi hd from me for $20 ea (ready-to-use)(will ship international) To be used with one of these fine

#Terminated SCA adaptors#.

 

[Paralel]

You make a good point, Uni. I guess there is a certain amount of duty to protect the greater public from themselves.

 

[max1zzz]

I do agree with uni, that is why i did add that note, the only reason i didn't test it on a 68k first is because i had just got in from collage and didn't fancy waiting the half hour it can take my 450 to format a large hdd

A list is a good idea, i would add that it might be a good idea to add weather a drive needs the extra lines terminated or not

 

[gsteemso]

These things look awesome. Nice work! I’ll definitely keep this thread in mind for when the 1GiB drive in my Quadra 840AV inevitably dies for good. (It’s not doing well at all.)

 

[max1zzz]

Got my latest drive, a 18.4GB compaq

And it is not compatible, although it works in my G4 QS with a scsi 1 card it dose not work in 68k's

Drive model number is:BD01864552

So there's one to avoid.

will see if it works on the 8600's fast scsi bus.

Also got my order of SCSI -> 50 pin adapters, just hopeing my reel of 0805 110R smd's is going to turn up in the next few days so i can get to work on these adapters...

 

[NJRoadfan]

Was the 18.4GB formatted using Apple's Drive Setup under OS9? OS X doesn't install a Mac driver partition required for classic Mac OS.

 

[max1zzz]

No, but i tried to format it using apple hd sc setup under 7.5 and it just wasn't seen

I actually tried it on the 450 before the G4, and it still wasn't seen

 

[max1zzz]

Well, SMD's really neaten things up, even if there a little tricky to solder





(that nasty looking stuff round some of the resistors is just excess flux i haven't cleaned, should look a bit better once thats cleaned off)