BBC Master 128 - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

SteveCG · 1st Oct 2014, 9:31 am

Aah Chris,

I was assuming a 3.5" drive. Perhaps the folk with faulty drives can confirm what size they are?

cmjones01 · 1st Oct 2014, 10:44 am

I assumed 5.25" drives! With a Master, it could be either, realistically. Most BBC Micro discs were 5.25", but with the advent of the Master Compact, 3.5" started to gain popularity, and so some 3.5" drives were used with later BBCs. The original problem was that there is some subtlety of the index pulses on a 3.5" drive that the original 8271 disc controller in the BBC didn't get on with. The 1770 used in the B+, Master and Master Compact didn't have that problem.

Chris

1st Oct 2014, 9:31 am	#21
SteveCG Nonode Join Date: Jun 2009 Location: Herefordshire, UK. Posts: 2,495	Re: BBC Master 128 Aah Chris, I was assuming a 3.5" drive. Perhaps the folk with faulty drives can confirm what size they are?

1st Oct 2014, 10:44 am	#22
cmjones01 Nonode Join Date: Oct 2008 Location: Warsaw, Poland and Cambridge, UK Posts: 2,677	Re: BBC Master 128 I assumed 5.25" drives! With a Master, it could be either, realistically. Most BBC Micro discs were 5.25", but with the advent of the Master Compact, 3.5" started to gain popularity, and so some 3.5" drives were used with later BBCs. The original problem was that there is some subtlety of the index pulses on a 3.5" drive that the original 8271 disc controller in the BBC didn't get on with. The 1770 used in the B+, Master and Master Compact didn't have that problem. Chris __________________ What's going on in the workshop? http://martin-jones.com/