thompson@apr.UUCP (The Software Warrior) (09/15/85)
Somewhere not to long back I read that the ST had an industry standard
FASI(?) hard disk interface. At the time I passed it off as being a typo
meant to say SASI. However, after staring at the pinout for a while, I
realized that the intended interface was some sort of parallel interface
with DMA capability and that the lines available were actually processor
bus lines. Since they provide only one address line, and only eight data
lines with no UDS or LDS, I assume that their can only be two I/O
registers. The port configuration looks very similiar to what the NCR
5385 SCSI protocol controller chip provides but without enough address
lines to get at the full set of control/status ports. Anyhow what I was
wondering ...
1. Does anyone know if there is such a thing as a FASI interface, and if
so where can I get information on it? (Any leads at all appreciated.)
2. Does anyone know what is inside a developers hard disk. If there is a
certain chip (or chips) that is being used to talk to a standard hard
disk interface (Xebec, or SASI) ?
3. Do any of the software developers know what the format of the hard
disk registers are ? (If the format is simple enough this could help
alot.)
4. Basically any information at all about this hard disk port on the ST
would be appreciated.
The end result of this all is that I am trying to hang a hard disk on
this monster that I already have.
Pin out of the ST Hard Disk Port.
1 - Data 0 2 - Data 1 Pins 11,13,15, and 17 Ground
3 - Data 2 4 - Data 3
5 - Data 4 6 - Data 5
7 - Data 6 8 - Data 7
9 - Chip Select (Probably Decoded Inside the ST to select the interface
port.)
10 - Interrupt Request (Probably an interrupt to the 68000)
12 - Reset (Probably a reset signal from the 68000)
14 - Acknowledge (Probably a DMA data acknowledge signal)
19 - Data Request (Probably a DMA request to the DMA controller in the ST)
16 - A1 (Probably an address line that selects between to registers on
the interface port chip(s).)
18 - Read/Write (Probably processor and DMA generated read/write signals)
+-------------------------------------------------------------------------+
| In Real Life : Edward D. Thompson | Just Visiting |
| UUCP Address : ..cbosgd!apr!thompson | This Planet |
| Compuserve Address : 75136,2024 +-------------------------+
| Postal Address : 2715 Tuller Parkway Drive, Dublin, Ohio 43017 |
| Phone : (614) 766-6901 |
+-------------------------------------------------------------------------+
* General Disclaimers, Trade Mark Recognitions, and anything else....... *rb@ccivax.UUCP (rex ballard) (09/24/85)
> > Somewhere not to long back I read that the ST had an industry standard > FASI(?) hard disk interface. At the time I passed it off as being a typo > meant to say SASI. > The port configuration looks very similiar to what the NCR > 5385 SCSI protocol controller chip provides but without enough address > lines to get at the full set of control/status ports. > I don't know where you got FASI, but the hard disk port is supposed to be SCSI, with a 1.33 mb maximum transfer rate (almost faster than the 68000 can "copy" from a RAM disk). The pins available are the same type that the HABBA drive uses on the MAC (inside the machine). There a few drives that support the SCSI interfaces already available. In fact, the developer's hard drives are apearently modified MAC drives (different cable). From the AMPRO "Little Board" ads, it also appears to enable interfacing to networks, I/O expansion... SCSI interface boards are also available for the IBM PC. (Could there actually be a standard developing here?). Now, if we could just get someone to explain SCSI to us, we would know what the limits are. Could you tell us more about the 5385 chip? What lines does the ST seem to be missing?
freed@aum.UUCP (Erik Freed) (09/27/85)
Is the ST port really SASI? (Are we talking similar or are we talking
identical) In otherwords can I use a industry standard SASI controller
and Disk? This would be great.
--
-------------------------------------------------------------------------------
Erik James Freed
Aurora Systems
San Francisco, CA
{dual,ptsfa}!aum!freed