3 Jun
2011
3 Jun
'11
12:50 p.m.
Good idea to use a guard. For the work I do on
Not directly applicable to the BA23 (physcial problems with fitting the
things), but at one time you could get miniature toggle switches where
you had to pull out the lever slightly to flip them. RS and/or Farnell
used to do them (they may still, although I've found a lot of useful
switches have been discontinued).
When I added a doubles died drive as a second drive to my CoCo ssytem, I
added a little logic so that it could appera as either a pair of single
sided drives (/D1 and /D2) or as one double-sided drive (/D1). Obviously
flipping the mdoe in the middle of disk operations was a sure way to
corrupt a disk so I used one of said switches there.
I did this over ten years ago without a schematic,
so I forget the tests that I did. Since it worked,
I assumed that the single switch was able to carry
the extra current for at least a reasonable time.
I am sure it can. We are talking about logic-level signals here, I would
guess the currents involved are measured in 10's of mA at most. No normal
switch is going to have problems with that.
If you have the information, can you describe the
circuits that were soldered and the size of the
resistors? In addition, would Tony (I guess this
is twice that I have taken your name in vain -
I apologize) be able to suggest the additional
circuits needed to add the green and orange
LEDs to show the same status that the 6 button
front panel for the BA23 shows?
Assumeing the circuits on Pete's web page are accurate, it should be
quite easy to do this.
Are the 4-button and 6-button panels base o nthe same PCB, with the
former being partially populated, or are they different PCBs?
-tony