28 Nov
2010
28 Nov
'10
11:46 p.m.
On 28 Nov 2010 at 22:50, Phill Harvey-Smith wrote:
Hi,
Does anyone happen to have the schematic of one of the SCSI->MFM/RLL
boards ? I have the Adaptec ACB-4000 and Xebec S1410A board documents
from bitsavers but thy only have the schematics for the computer end.
All the talk of interfacing to SCSI has got me wanting to have a go
:) I'm just want to look and see how it was done in the olden
days....failing that I guess I'm gonna have to start tracing
tracks.....
I've got a couple of the OMTI 3127 RLL-to-SCSI converters. They
basically have the OMTI RLL hard disk controller, a Z8 MCU, some
EPROM, RAM and an NCR-licensed SCSI bus interface chip.
Another example of SCSI-to-something else can be found in the various
tape drive interfaces. Cipher used an 80188 and an NCR SCSI
interface for their M990 tape streamer (the drive controller itself
is a Z8002 MPU).
You can see a similar pattern in scanners and the like--an MPU, some
ROM, some RAM and a bus interface chip.
If I were to make a SCSI hard disk substitute today, I'd probably use
an ARM M3 with external RAM interface (for cache), some SRAM, an
SDHC for storage and whatever I could find for a bus interface IC.
On the other hand, SCSI-to-USB may be a more logical choice, given
the wider range of USB devices available.
--Chuck