exxos's Atari, Amiga & retro forum

mrbombermillzy wrote: 18 Nov 2021 12:17 Also, if it helps clear things up, the TT SCSI IC is NOT the end of the chain if you dont have board terminators, its in the middle of the internal/external chain. :)

Good to know. Be interesting to look on the schematics and see where the termination lies.

I haven't used anything SCSI for years, but I do remember the Y cable configs where the HBA was in the middle and the cable middle connector plugged into that with a drive at either end, and only the drives were terminated.

rubber_jonnie wrote: 18 Nov 2021 12:49 I haven't used anything SCSI for years,

Neither have I, apart from some quick TT internal HDD drive/external CDROM setup about a year ago.

The real test will be when I finally set up a TT/Falcon with internal HDD drive, external CD-ROM drive, 2x Yamaha CBX-D5 units and an 'audio record' drive at the end of the chain. (There may even be a scanner in there for good measure too).

Incidentally, I checked the SCSI2SD v6 wiki and it has now been tested and works with a TT...that's just after I recently purchased the v5.5! :evil:

mrbombermillzy wrote: 18 Nov 2021 13:36

rubber_jonnie wrote: 18 Nov 2021 12:49 I haven't used anything SCSI for years,

Neither have I, apart from some quick TT internal HDD drive/external CDROM setup about a year ago.

The real test will be when I finally set up a TT/Falcon with internal HDD drive, external CD-ROM drive, 2x Yamaha CBX-D5 units and an 'audio record' drive at the end of the chain. (There may even be a scanner in there for good measure too).

Incidentally, I checked the SCSI2SD v6 wiki and it has now been tested and works with a TT...thats just after I recently purchased the v5.5! :evil:

Isn't it always the way that you buy something just before something better is released!!!!

I used to be a field service engineer and dealt with a lot of SCSI, mostly 50 pin to begin with, then 68 pin and finally SCA. I moved on after that and started to do more software related stuff than hardware.

The TT as stock has terminating resistor packs in sockets right next to the DB25 port on the motherboard. The internal drive also needs its terminators installed.

In practise the TT's SCSI generally works fine even if the resistors are removed from the motherboard and nothing is connected as the wires are so short. When plugging in external devices they definitely need termination. Depending upon the item I either have a "Centronics" passive terminator or a Sun branded micro-DB50 active one (with an LED on it showing that there's power from the bus).

stephen_usher wrote: 18 Nov 2021 14:02 In practise the TT's SCSI generally works fine even if the resistors are removed from the motherboard and nothing is connected as the wires are so short.

While I wholeheartedly agree with what you say, I was trying to keep the number of variables down to a definitive working amount for Steve's sake. :D

rubber_jonnie wrote: 18 Nov 2021 13:47
Isn't it always the way that you buy something just before something better is released!!!!

I used to be a field service engineer and dealt with a lot of SCSI, mostly 50 pin to begin with, then 68 pin and finally SCA. I moved on after that and started to do more software related stuff than hardware.

I actually researched the v6 a while ago and it was at that time faster than the v5.5, but didn't seem to work on some 'classic' SCSI stuff (TT included, or at least hadn't been properly tested).

Oh well, now it does. Yay for progress, I suppose. :roll:

mrbombermillzy wrote: 18 Nov 2021 14:15

rubber_jonnie wrote: 18 Nov 2021 13:47
Isn't it always the way that you buy something just before something better is released!!!!

I used to be a field service engineer and dealt with a lot of SCSI, mostly 50 pin to begin with, then 68 pin and finally SCA. I moved on after that and started to do more software related stuff than hardware.

I actually researched the v6 a while ago and it was at that time faster than the v5.5, but didnt seem to work on some 'classic' SCSI stuff (TT included, or at least hadnt been properly tested).

Oh well, now it does. Yay for progress, I suppose. :roll:

And Yay that people actually build this kind of stuff at all :)

rubber_jonnie wrote: 18 Nov 2021 14:39 And Yay that people actually build this kind of stuff at all :)

Of course. It's not a problem at all really. I don't expect the TT needs any kind of ultra/wide/fast/U320 bandwidth anyway. :lol:

mrbombermillzy wrote: 18 Nov 2021 14:55

rubber_jonnie wrote: 18 Nov 2021 14:39 And Yay that people actually build this kind of stuff at all :)

Of course. Its not a problem at all really. I dont expect the TT needs any kind of ultra/wide/fast/U320 bandwith anyway. :lol:

Nope, standard 50 pin SCSI 1 AFAIK, so nothing unsurmountable.

mrbombermillzy wrote: 18 Nov 2021 14:15 I actually researched the v6 a while ago and it was at that time faster than the v5.5, but didnt seem to work on some 'classic' SCSI stuff (TT included, or at least hadnt been properly tested).

Oh well, now it does. Yay for progress, I suppose. :roll:

I've had a V6 in my TT for ages with no problems at all.