SCSI CD writer in A4000T query

[Lemonty]

I am trying to attach a SCSI-II CD-R to the A4000T's SCS-II controller. Since I have no 'A4000T User Guide', I am failing to do this relatively easy job. For instance, I have no insight in what the DIP-switch does, which is located at the back of the computer. Now the CD device is not recognized by any software that checks for devices on '2nd.scsi.device' (I used 'SCSI_inquire'). I guess the SCSI termination is my main problem.

The CD-R is a Matsushita-Kotobuki (Panasonic?) one featuring jumpers on the back for (1) scsi adress number 1-2-4, (2) parity, (3) terminator, (4) term power.

The DIP-switch has the following diagram on a sticker next to it:

---------------ON------OFF
8 LUN-------0--------0-6
7 TERM-----ON-----OFF
6 SYNC-----ON-----OFF
5 SPIN------NORM-LONG
4 SCSI------FAST--NORM
3 \
2 - ADR
1 /

What DIP-swith configuration and CD-jumper configuration should I use to get this thing working?

PS: Wanted: the A4000Ts User Guide ;p

Thanks! :-?

[Lemmink]

I can only tell you my setup:
Only Jumper 4 on everything else off. As I have some external SCSI-devices termination is off so for you I suggest you set 3 also to on.
Connect the CD-R to the internal SCSI-connector (that is the one on the tiny board with the DIP-switches next to the floppydriveconnector , not the other one with the single tilted connector that faces upwards. That is the other end of the SCSI-row and is terminated by the board it is on. Don`t ask me why there is even a connector)
Make sure the last Drive on the SCSI-row is terminated as well.

[sprocket]

I have a 4000T and the user guide so I'll post the function of the dip switches.

Switch 1 - Set the SCSI address for the host adapter.  The default is 7 with switches 1,2,3 set to "OFF".

Switch 4 - "OFF" indicates that the SCSI Fast Bus feature is enabled.  Set this switch to ON if none of your SCSI devices supports SCSI Fast Bus.

Switch 5 - "OFF" indicates that your system uses the standard spinup (booting) time.  Set this switch to "ON" to request a longer booting period.

Switch 6 - "OFF" indicates that the Synchronous Mode feature is enabled.  Set this switch to "ON" to disable the synchronous mode.

Synchronous mode does not require acknowledgement for every byte transmitted, which can mean improved response time with most SCSI devices.

Switch 7 - "OFF" indicates that you do not have any external devices.  This activates the terminator on the motherboard since this in one end of the SCSI bus.

Set this switch to "ON" when you install an external device, then set the external termination on the last device.  This disables the terminator on the motherboard since it is now in the middle of the SCSI bus and not at the end.

Switch 8 - "OFF" indicates that only LUN 0 is recognized.  Set this switch to "ON" to enable the system to recognize all LUNs.

Essentially you are okay with all switches OFF unless you have an external device connected when you should turn switch 7 to ON and terminate the last external device.

Hope this helps.

[Castellen]

@Lemmink: The connector on the board by itself that faces upwards is a terminator for the end of the chain.
It's done like that so if you want to, you can have the end of the SCSI cable in a SCSI device, which is what I do in mine as there is 4 internal devices so the cable would be too short otherwise.

@Lemonty: It is easy, but just a matter of getting everything set up right.
As mentioned, make sure termination is enabled on one end of the chain by having switch 7 in the OFF (down) position, only if you have no external devices.  The other and of the SCSI ribbon cable should be plugged into that upward facing socket on the module, or plugged into a SCSI device with termination enabled.
Switch 8 should be ON (up) to make the controller see all logical unit numbers.

All the other switches should be OFF (down), which is how mine is anyway.

Also note that the sticker on my A4000T (which you described above) has the 2 horizontal rows describing switch position printed around the wrong way!!  This really confused me at first.  Though the 1-8 switch numbering is correct.

On your drive you shouldn't need the termination power link, this is provided from the motherboard.
Leave the parity jumper in the factory default position, and if there is any block size jumper, it should be set to 512.

It it still fails to work, you can try changing the parity or fiddling with synchronous modes.  You can't do damage by getting it wrong, the worst it can do is not work.

Hope that helps.

[sprocket]

Just for the record, your new device is an internal SCSI device, right?

BTW, if your device is SCSI and on the 4000T SCSI bus it will show up under scsi.device and not under 2nd.scsi.device.

2nd.scsi.device is for IDE devices connected to the motherboard IDE header or some other IDE interface.  Essentially IDE devices are handled through 2nd.scsi.device.

I'd be careful about putting a device on the end of the internal ribbon and disconnecting the
internal termination.  I'd just buy a longer ribbon and connect it properly.

Also, leaving switch 8 on is unnecessary unless you have several LUNs.  It will just make your machine take longer to boot.

[Lemonty]

@Lemmink:

Thanks, I actually connected the drive to what appears to be a terminator socket (the upward facing connector). It looked so right to me...

@Sprocket:

Drive now appears correctly under ... 2nd.scsi.device. The scsi.device is where my IDE drives are connected to. Thanks for the manual description.

@Castellan:
You sure know a lot about all things Amiga!

Wish you all a happy change-over to the New Year!