Multiple internal SCSI devices in a SE/30?

[ants]

Apologies if this has been asked before - but is it possible to chain multiple SCSI drives or other devices to the internal port on a SE/30 logic board?

Specifically, I'd like to mount an Asante SCSI Ethernet device inside the Mac instead of outside. Obviously there'd be some changes to the connector required...

Thanks in advance.

 

[Trash80toHP_Mini]

Shouldn't be a problem other than the anemic power supply.

 

[ants]

Awesome, thanks.

 

[oldappleguy]

here is a scsi ribbon cable with two connections on one end . 

 

[mpe]

Is it necessary to configure bus termination in any way when adding more than one internal device?

 

[Trash80toHP_Mini]

The last device on the end of the internal cable needs to be terminated exactly as the last device on an external chain. Easiest way to do it would be to make sure the last device remains the internal HDD which is already terminated.

 

[olePigeon]

Could you just put a terminator on the last connector?  Assuming you got one with more than 3 connectors.

 

[Trash80toHP_Mini]

That's how it's commonly done on SCA cables, the terminator is built into the end of the ribbon cable. So long as you figure out how to remove termination from the Apple HDD, assuming it's still in there that'll work just fine.

Internal termination's exactly the same deal as on the chain on the other side of the external connector. It's one unified bus (chain) that needs termination resistors at each end to prevent "bounce" of the signal and the maximum device limit = Internal + External bitsies.

trag's your man for SCSI voodoo. He's got a pinned topic about it in Peripherals.

 

[Trash80toHP_Mini]

Dunno what ants has up his sleeve, but this ASANTE MICRO EN/SC has slowly been making its way into a Duo 2300c/TB HDD bay along with some kind of chipthingie/IDE adapter for more than a few years now. Temptation was to throw it into the PB150 for a while, but now I'm thinking the VONETS adapter might fit into the modem bay, mounted to a Power Board or denuded Modem for the Duo with an AirPort Antenna in the lid. h34r:



Can't imagine it's not well terminated, but haven't really looked that far ahead quite yet. Shouldn't matter as it'll be the only internal SCSI device. Temptation to drill small holes into the wrist rest for blinkage is almost irresistible. [}] Desoldering the connector and hardwiring the 10bT connection to the desoldered VONETS connector, thruhole to thruhole will be next. May add a Male-Female plug setup to move the bits around in different machines for WiFi playtime.

I can see one of these in a version of joe the zombie's SCSI2SD sled along with the VONETS bits. mount it sideways in the front and angle the LEDs so they light up the bottom of the cooling vent  .  .  .

 

[ants]

@Trash80toHP_Mini haha that's EXACTLY what I'm trying to do! You might remember from another post that I can't get my Daystar Turbo and other PDS network cards to work together - so I'm going to attempt to use a SCSI Ethernet adapter instead.

I also have an Asante Micro EN/SC, and I hope to change the connection to a 50 pin ribbon connector.

In regard to SCSI termination, I'm assuming that the Asante adapter is already terminated. I also have a SCSI2SD in my SE/30, and I'm pretty sure that can be configured to not terminate.

So I'll try the SCSI2SD as the first device, and the Asante on the end. Think that might work?

@oldappleguy thanks for the pic, I've ordered one off eBay.

 

[Trash80toHP_Mini]

[]  That would be the way I'd go.

It'll be easy enough to buzz the connections of the stock cable from the PB HDI-30 connector pinout.

Tag each line with the pin number in the middle and close to the HDI-30 and clip as you go.

I'll be leaving approximately 25mm on the HDI-30 with the tags for reference/re-purposing if and when.

Your process is easier, lining everything up with a conversion table to IDC-50 and crimping on a connector is a piece of cake. I'd probably start out with a SCSI extension cable from CablesOnline. Lop off and strip the ribbon from the male connector. Line up your wires, punching each a bit in the right spots and punch the connector down in a vise.

I've gotta convert the laptop flex cable connection.

Neater way might be to desolder the headers. Solder the connectorless wires of a ribbon cable's end into the thruholes. Do it an artful distance from the connector for the SCSI2SD.

You could pull 'em both out and make an external drive with WiFi to hook up to any of your Macs. Build in a Powered USB Hub and Wombat, the possibilities are endless.

Now that I think of it, a ZFP case with a Desktop SCSI EhterNetAadapter and all those other goodies built in would be pretty cool.

 

[Trash80toHP_Mini]

We're looking at this a bit backwards here. The VONETS board should go INSIDE the Asante Micro EN/SC, hardwired to the 10bT jack with its cute little antenna(s) wagging out the BNC hole from behind ANY compatible PowerBook like a cute little dog. All would be powered from the ADB tap.

 

[ants]

Great minds think alike - I had already ordered that exact cable from CablesOnline

 

[Trash80toHP_Mini]

.  .  .  or along divergent paths. )



The only one I've found in this size with mounting holes has active termination, which might not be a bad thing. This type could be slotted into a a double decker mod of joe's printed chassis. SCA connector would be desoldered anyway, so its ground lug hole would work if drilled out or .

Solder wires from Micro EN/SC cable into appropriate thruholes of removed SCA connector for the neatest adaptation I've come up with thus far. Still not elegant, but we might be getting a bit closer?

Power takeoff mod for any number of things inside the case available.

 

[ants]

Well it sure ain't pretty, but here is my Asante Micro EN/SC to 50-pin SCSI adapter. I haven't tried it out yet, and the chances are high that I've stuffed up my wiring!

I'll give it a go in the next few days and report back

 

[ants]

@Trash80toHP_Mini I need your help. I'm at my wits end trying to get my adapter cable (above) to work. The cable is now much messier, after a string of failed attempts:



Matching up all the pins was pretty easy (Data0 to Data0, ACK to ACK etc etc) - except for the Ground wires. There's so many of them (especially on the IDC 50 end) - and I'm not sure what I'm supposed to do with them!

You'll see in my first picture in the previous post, I had chopped off all the ground wires that I didn't have an associated connection for on my HDI-30 connector end. When I plugged it in, the SCSI2SD activity light just came on solid and the Mac would not boot. (Note that I've sorted out my SCSI termination issues - the SCSI2SD terminator is disabled, since the Asante Card is terminated).

So then I connected up all of the unused ground wires and linked them up to other (random) ground wires on the HDI-30 (as above pic). It is much more promising - the Mac now boots successfully - but very shortly after it bombs out with a bus error. Strangely, the very first time I booted up, everything seemed to work for quite a few minutes until I got a bomb error - but ever since then I get an immediate bomb after startup.

A few questions:

1. Is there a specific order in which the Ground wires should be connected? i.e. should certain ground wires be paired up with other lines, such as REQ/GND, IO/GND? If so, how would I figure out what the pairs are?

2. What am I supposed to do with all the odd ground wires on the IDC 50 cable (1, 3, 5 ...49)? In the pic above, I attempted to join them all together - but no joy. There's also some even ground wires on the IDC 50.

3. I'm unsure if pins 23 and 27 on the IDC are ground wires, or "reserved" wires (there's conflicting info online) - although I've tried them both connected and disconnected, but no joy either way

There's 10 ground wires on the HDI-30, and 31 on the IDC 50...

 

[Trash80toHP_Mini]

Hrmmm?

- Have you got a PowerBook cable or adapter to test baseline function? That would be your first step.

- The ground lines are set up to alternate between signal lines to prevent crosstalk.

- They'll be connected to the ground plane at one or both ends

Looks like you've lopped off the PowerBook connector? In the SE/30 I think I'd can the cable adaptation approach and solder the NIC cable's wires into the thruholes of the desoldered SCA connector of a 50 Pin SCSI adapter PCB.



edit: looks like I just screen capped and uploaded the same damn pic as above! :blink:

 

[Trash80toHP_Mini]

Where are you tapping power for the NIC? Make sure that's not flaky? The adapter PCB' power connector will let you use a Y cable and a resistor? Maybe the one on board is good enough?

Now I got nuthin.

 

[ants]

So I think the lesson here is to always listen to @Trash80toHP_Mini, otherwise you'll just blow time and money

Can you tell me a bit more about the SCA to 50-pin adapter? The SCA connector has 80 pins right? And the HDI-30 has... well... 30 pins (well, 28 on the Asante connector)

I found a pinout here: http://old.pinouts.ru/HD/scsiexternalsca80_pinout.shtml

How do I not hit the same problem with my Ground wires?

Many thanks.