2

A simple one if you know the answer: how many pins does the SCSI interface on the Mac IIsi have.

I thought I could just pull drives from my SE/30 collection but it sounds like that's not the case. Please advise.

bmike
  • 235,889
0xF2
  • 123

2 Answers2

2

The Mac SE/30 and IIsi use the same SCSI interfaces, and you should be able to swap drives freely between them (though a Mac OS system that'll boot one won't necessarily work with the other). More specifically, both have:

  • A 25-pin DB-25 external connector. This is nonstandard, but it's the same interface Apple used starting with the Mac Plus, and IIRC ending with the beige PowerMac G3s.
  • An internal 50-pin header connector (data) and 4-pin Molex power connector. This is standard; see the "Internal Industry Standard 50-pin SCSI F/W" connectors in this IBM doc. In fact, pretty much all 8-bit ("narrow") SCSI drives from that era use this same internal interface (though the standard external interface is a 50-pin Centronics connector, with the same pinout as the internal header version).
Gordon Davisson
  • 33,702
1

The IIsi has a DB-25 SCSI port.

Unless you really want to reuse existing drives for reasons (and there are several I can imagine) an emulator is also a good option.

Note the IIsi doesn’t provide termination power, so that might be why you are thinking the pin out is sus.

The IIsi does not provide TERM POWER. It must be powered via the Berg connector or USB on the BluePill.

From the IIsi service manual:

"The 85C80 [SCSI controller] does not provide the internal SCSI disk drive with termination power; the drive provides the termination power.”

bmike
  • 235,889