Conference hydra::amiga_v1

    This is out of the 2090A controller manual.
    
    pin	name 
    
    1	REQ
    2	MSG
    3	I/O
    4	RST
    5	ACK
    6	BSY
    7	ground
    8	DB0
    9	ground
    10	DB3
    11	DB5
    12	DB6
    13	DB7
    14	ground
    15	C/D
    16	ground
    17	ATN
    18	ground
    19	SEL
    20	DBP
    21	DB1
    22	DB2
    23	DB4
    24	ground
    25	TPWR
    
    Hope this helps
    
    Jean
    		

    Thanks Jean,
    This will help...  Now for the timings of the signals...  Ah...
    it never stops (but it's fun!).
    John
    

I could mail you a spec. What's your mail stop?

John (NOT a spec distribution service :-) )

    If  you  want  to  simplify your life you can get a SCSI to QIC36
(1/4" streaming tape electrical  interface  spec)  adapter  from  the
wholesale  place  in  Milpitas. It seems you can plug in a WangTek or
several other tape drives into this interface and have a  1/2  height
SCSI  streaming tape system. The place I am talking about above sells
the adapter for about $100 and  detailed  manual  for  $5.  They  are
likely to have a tape drive there too.
���
    Unless  you  write  a special driver you would have to format the
tape before using it and access as a disk with one track thousands of
blocks long. After that it looks like a unwound disk.

	-SES

    Thanks for the input.  I was looking at trying to treat the tape
    as a strange disk so I wouldnt have to write a driver.  Thanks for
    the tips on sources.  I think it should be possible to build a
    professional tape backup system for around $300, but I've been wrong
    before!  The ones on the market for $600 - $900+ are just a bit too
    steep for my blood.
    
    John
    

    RE: .3
    
    Thanks for the offer of the specs!  Mail stop is:
    
    John Bernard
    YWO-E4
    
    

    
    
    	I have been using a TZK50 on a GVP SCSI controller for a while
    now. The GVP driver provides an interface to send raw SCSI commands
    to any device.
    
    	You should note that tapes and disks have different command
    sets ( i.e. tape can't look like a disk ). The SCSI spec contains
    all the information you will need.
    
    		Steve Peters
    

    Steve,
    
    	It sounds as if you have written some code to use the TZK50.  If
    you don't mind, I sure would find it real interesting to see some
    examples.  That's especially true with more and more SCSI products
    being available  (from us and others).
    
    Thanks,
    John B. Fisher

    Steve,
    
    Me Too!!  I called CLtd for their libraries to write a driver, but
    based on their past response (or lack thereof) I could turn blue
    waiting.  Also, what controller are you using on the TZK? (ACB3530?).
    
    John
    

    
    
    	I'm not sure if my code will help anyone. I'm using a GVP SCSI
    controller with a PROTO driver.  About 6 months ago I bought the
    GVP controller because they gave you a interface to send raw SCSI
    commands to a device. I then foud out it had never been tested.
    After writing some test code that also failed using a disk I got
    them to believe that it might be their driver. After 4 attemps
    they got me a proto driver that works. The only problem is that
    it doesn't work under 1.3 AmigaDos. They sent me a new driver
    that works under 1.3 but the raw SCSI interface is broken again.
    
    
    		Steve Peters
    		Using 1.2 and waiting for a new driver !
    

    If it would help, the local dealer that I have been dealing with has
    had a major impact on GVP's product directions.  GVP has been very
    favorable to this dealer.  In fact the suggestions have been quite
    successful...  So I might be able to pass along some additional
    suggestions for their product.  Such as,

    	1.  Ability to cleanly use the Adaptec controller
    	2.  Ability to send raw SCSI commands to a device

    I'm open to suggestions...  I have gotten the Adaptec controller to
    work (and quite well at that - for one disk only).  However, it would
    be very nice if it was supported.  They might also see the advantage of
    having other SCSI equipment manufacturers build utilities (or
    supplemental drivers) that can take advantage of GVP's controller. 
    You can imagine the possibilities...
    
    So if we decide what we want, then maybe we would be able to get the
    same message to them from several different sources (naturally
    including ourselves).
    
    =jbf=

I would like to write out 16-bit digital samples to a tape in non-real time and then read
them back in real time, perform D/A conversion on them, and play them through my speakers.
So, I have two questions:

	1) Can I use a streaming tape drive like a fixed block length tape drive?

	2) Will such a drive support the data rate needed for real time playback?
	   Real time playback in mono would somewhere in the range of 40-80K bytes
	   per second.  Double that rate for stereo.

regards,
-jim

    
    
    	The TZK50 has a fixed block length mode but I don't know why
    you want to use it. Fixed block length doesn't make it look like
    a disk. The TZK50 can handle about 50-60KByte/second.
    
    		Steve Peters
    

Most of the programs which compute music waveforms were written in the '60s and
'70s (at least the ones I have) and write fixed length records to tape, so I
need to write fixed-length records.  When writing in 'fixed-length' mode, can
the drive still support 50-60KB per second?

thanks,
-jim

    
    
    	re .14
    
    	As long as the records are multiples of 512 KByte, then 
    it will read or write at 50-60KBytes/Sec.
    
    		Steve
    

    
>    	As long as the records are multiples of 512 KByte, then 
>    it will read or write at 50-60KBytes/Sec.
    
	512 KBytes, really?  Not 512 bytes?

regards,
-jim

    
    
    	re .16
    
    	Your right 512 Bytes not KBytes.
    

    
    
    	I have been Beta testing GVP's new driver. It works with
    Amigados 1.2 and 1.3 . The direct SCSI command interface is
    working very well. I have some test programs working that control
    a DEC TZK50 tape drive. I hope to get a BACKUP program working
    in a few weeks.
    
    	So, if anyone is looking for a BACKUP system for their new
    xxx MByte disk this might be one way to do it.
    
    		Steve Peters
    

What do TZK50 drives cost through employee purchase?

	Thanks,
		-SES