SCSI questions

[Cyberus]

I have more questions for you guys, hope you don't mind!

1) What SCSI interface options are there for the A1200(T)? I know there is the PCMCIA 'Squirrel', but is the best/cheapest choice or are there other options. Do they all go into the PCMCIA port?

2) I read somewhere that PCMCIA ports aren't very quick. Does this mean that a PCMCIA SCSI interface will result in transfer speed not much faster, or even slower (?!) than IDE.

3) What is the best option if I want to have a ton of devices. I know that you can unsually daisy-chain a total of 7 SCSI devices. Also, a standard A1200 can support 2 HDs, but I understand you can get IDE interfaces that support more. (In which case which ones are available, and where do they plug in?) Finally, 'mixing and matching' a combination of devices may be a solution. Any recommendations which devices will be better in SCSI format and which in IDE (CD drives, CD-RW, HD, etc.)

4) Finally, what are the IDE/SCSI solutions for the A1?

Thank you!

[AmiDog]

1. Many accelerators have either SCSI onboard or a SCSI-addon. Squirrel connects to the PCMCIA-port and there even was an adaptor which connected to the IDE-port.

2. The PCMCIA-port of the A1200 wont do much more than some 1.6MB/s (if I remember correctly). A much better option is an accelerator with SCSI.

3. There are several buffered 4-way IDE-adapters which connect to the IDE-port.

[Karlos]

Anybody know where I can get a cable that adapts the BlizzardPPC SCSI connector to a standard SCSI ribbon cable for internal devices?

[miles]

1) The best option is SCSI on a trapdoor Blizzard (030,040,060,PPC)
card.

These cards use 32 bit DMA and are fassst with low CPU overhead.

2) PCMCIA SCSI is 16 bit and really slow with high CPU useage, avoid!

3) If you want a lot of devices SCSI is the way to go.  IDE can have 4
devices with a Powerflyer adaptor.  (See Eyetech and Powercomputing in
the UK or Softwarehut in USA for IDE options).  For home use I do not
really think it matters IDE or SCSI, SCSI will be faster, lower CPU
useage, IDE will be alot cheaper.

4) Don't know :-)

[Crumb]

I saw in Amibench this message:

For Sale : Internal Blizzard PPC SCSI cable - £19.99 + £1.60 P&P.

After searching all over the place for a cable to link from my Blizzard PPC board to my internal SCSI devices I came up with nothing. Compromises, bodged solutions, 8” long converters, etc, etc – every solution seemed to be expensive and nasty.

I have now solved this problem by having a custom cable made, this cable has 4 SCSI connectors on it (more on request) and a high-density 50-way connector that plugs directly into the cable you get with your Blizzard PPC board.

The high-density connectors are very expensive plus the crimping too for the job costs over a grand, hence getting the cables made is an expensive business. But look at it this way, for your money you get a proper 50-way cable, grounds between every signal line and a cable that will run your SCSI chain faster than any other solution. Signal grounding and proper termination are essential for SCSI; otherwise you loose speed on data re-tries.

Many thanks AmiBench for your great service.

Posted 21/2/03

John
j.matrix@ukonline.co.uk

NOTE: I don't know how well done are these cables and don't know anyone who has bought him a cable, so if you buy him a cable do it at your own risk :-/

[Karlos]

@Crumb

Thanks for the heads up.

[SilvrDrgn]

You could always try Redmond Cable.  They build custom cables and even have a dedicated Amiga section.  Here's the URL - http://www.redmondcable.com.  You might need a browser capable of displaying Flash to view it.

[Cyberus]

Thanks guys.

@ miles
 I have an Apollo 040/40 card for my A1200. I read in an old  CU Amiga that some come with SCSI onboard, and if not it'll need to be sent to the manufacturers to be soldered on. Is this true (I am competent with a soldering iron, but I certainly wouldn't attempt THIS myself!)

[PaSha]

Cyberus wrote:
Thanks guys.

@ miles
 I have an Apollo 040/40 card for my A1200. I read in an old  CU Amiga that some come with SCSI onboard, and if not it'll need to be sent to the manufacturers to be soldered on. Is this true (I am competent with a soldering iron, but I certainly wouldn't attempt THIS myself!)

The Apollo scsi controller is totally useless! Avoid at all costs.
It is incompatible with newer harddrives, incompatible with OS3.5/3.9 (partially that is, it will boot, but as soon as you try to mount a cdrom or something else, it crashes), and has no DMA, which means it's a cpu hog. A powerflyer is better than the apollo scsi.
Repeat: The apollo scsi controller is a total waste of money (no matter how cheap it is) and will only cause headaches.
This goes for all apollo accellerator scsi controllers for A1200, A2000 and A3/4000.

-Paul