New finds: enough Torch stuff to sink a battleship

Yep, from some of the Torch docs I have, the case seems to be from a Torch 300-series workstation. These appear to have been the getting-more-familiar (!) BBC core with either a Z80 or 68k Atlas board attached and optional seperate disk cabinet. Seems like there was a stage in production where the disk ran via a controller in the expansion cabinet from a SCSI bus whilst the floppy used a seperate cable going to the controller on the BBC - not the 'SCSI floppy' type setup that my XXX has. fair call. Don't know why mine wouldn't, even if it were a prototype - if the circuitry's there on the card why not install the chips and sockets? Strange. Ok. The Torch monitors I have all need seperate syncs - explains the RGB board in the Torch 725 machine, which essentially seems to be a sync splitter from the BBC's composite output. yep, that fits with my 300-series theory. *wanders off to check... Just PSU and battery. Connections as follows: ^- front of board GND o o +5V GND o o +12V BATT o o -5V +5V o o nc v- rear of board The battery is obviously wired to ground too. 12V from the PSU also runs to the battery via a lot of black insulation tape; I haven't looked what's under there yet... The PSU isn't a standard XXX PSU (which I do have one of; I see the touch-switch connections you're talking about) - this machine has a 100W Wier PSU in it, likely stock to the 300 series if that's where this case came from. [Torch "Hard Disc"] Yep it is - says so on the board :) I have the manual for the Xebec interface to which it plugs into and that's definitely SASI / ST506. There's not much to the SASI board as it turns out - see earlier post; most of it turned out to be comms circuitry for driving the modem and nothing to do with the drive interface. Far as the SASI side of things is concerned, it's just some octal buffers, latches and the like; only about ten LSxx ICs. I had some time to mess around with the machine earlier, armed with spare BBC for testing (which turned out to have an intermittant RAM fault so wasn't much use :-) Far as the Torch machine is concerned, it seems to have a power-on reset fault such that it needs break hitting after powering up (I swapped the Torch keyboard for a real BBC one so at least my keypresses make sense). That shouldn't be hard to sort out. Now, without the SASI controller plugged into the 1MHz bus, if I unplug the Z80 board I can at least get the MCP to drop into the 'no Z80' condition where it gives an error message. I can't get that if the SASI controller is present (whether I have any combination of Xebec board & hard drive present or not) - just the MCP test on the screen and a flashing cursor. I'm curious why I don't see any disk activity at all, like it's not even trying to access the hard drive (ditto replacing that drive with a known-working unit, just with no valid data on it). Maybe the Xebec interface is faulty... [ Torch 725 ] nope :-( I'm quite amazed Torch could produce so many different boxes all based around the same BBC / Z80 / 68k choices though :-) Ahh, yet another case with the same guts then :) the Openchip? True. I do have the programming guide and the spec (which I believe you said that you had), but unfortunately not the chip. I bet the guy I got this stuff from has a whole pile of them! [tape drives] ahh, fair enough. Not come across anything that'll help you yet though :-( take the ol' tial-and-error approach huh? :) yep, I do - no schematics though :-) Just skimmed the docs, and it looks like it's a pretty flexible unit supporting up to 4 drives, which can be just about anything by the looks of it. Although there are built-in definitions for common drives I get the impression it's all pretty flexible so just about anything can be defined. Parameters can be set for a given drive, including data rate (125/250/500KB per sec), number of heads (i.e SS/DS), bytes per sector (128/256/512/1024), sectors per track (0..244), cylinders (0..245), write precomp, step rate, head settle delay, motor on/off delays, starting sector number etc. There's also a parameter for setting the relationship between logical and physical steps, for e.g. formatting a 40 track disk in an 80 track drive. They actually look like quite nice boards... one of those in the PC could come in handy... cheers Jules ________________________________________________________________________ Want to chat instantly with your online friends? Get the FREE Yahoo! Messenger http://uk.messenger.yahoo.com/