Tandon TM848-2 Floppy drive power

Date: Wed, 24 Jan 2007 04:56:58 -0500 From: "Kelly Leavitt" <kelly at catcorner.org> Subject: RE: Tandon TM848-2 Floppy drive power To: "General Discussion: On-Topic and Off-Topic Posts" The wiring harness is made by Tandy, in the Tandy 6000. That this harness has power going to a drive power plug that isn't used it typical of Tandy's shortcuts. They banked on the fact that Tandon would NEVER put another pin in that socket. ---------------------------------------------------------------------- Well, in all fairness to Tandy... Since the schematic for the TM848 shows what seems to be an option to omit the 12V regulator and supply the 12V through the power plug, perhaps Tandy at one time used (or planned to use) drives requiring 12V and kept the 12V supply on the connector for compatibility. Wouldn't be a problem since that pin is physically missing on "normal" drives. Sorta makes sense; in the S-100 world there generally wasn't a 12V supply and every drive needed its own regulator(s), whereas if a system already had a 12V supply then using the 24V and another regulator on the drive would be redundant and just waste power. And there are certainly numerous custom versions of the TM848 around, so you can't count on any particular drive being plug-compatible anyway. Yes, if you happened to plug a drive with the power off option on pin 4 into your 6000, there probably would be some magic smoke... Things weren't quite as "standard" in those days as they are today, FWTW. m