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Home Forums 68kMLA Score of the day — #8
Post #8 by techknight
Source Forum68kMLA
CategoryHardware
Post DateWed, 2 Feb 2011 - 05:00
Original URLhttps://68kmla.org/bb/threads/score-of-the-day.22253/
Post
yea, im just trying to get parts gathered up now. already have the C code figured out, etc....

the transceivers used in the open source project were for the low voltage differential SCSI system while our mac scsi wasn't differential. They may/may not work. i would hate to use standard glue-logic for driving the SCSI bus, as it would take a LOT of room. theres still some figuring out to do. but ill figure it out.

the AVR cant source/sink enough current to drive the SCSI bus directly. have to use the transceivers or tri-state glu-logic. I have the dead WDS-280 drive of mine i can scrounge its connector off the logic board. that way i can "plug it in" to the powerbook SCSI chain. but for experimental reasons, i may build it all on a breadboard and use the external centronics SCSI for testing. Only issue with this is the termination impedance matching might be a bit difficult as being on a breadboard adds extra capacitance/inductance to a high speed circuit.

a single 2.5 board is pretty darned crammed. i may expand it to 2 boards sandwiched together. at least that would give me some wiggle room, and its still within the limits of the 2.5 HDD size constraints.

mp.ls