[Coco] Copying over an IO ERROR

[Allen Huffman]

> On Feb 3, 2015, at 1:45 PM, Bill <cwgordon at carolina.rr.com> wrote:
> 
> Is there ANYTHING that can copy a disk after it hits an IO ERROR? I’ve got
> LOTS of Rainbow on Tape disks that will error out about ¾ through the
> process of backing the up. Isn’t there a subroutine that will copy track by
> track?

There were some POKEs on the CoCo 3 (or CoCo 1/2 with 64K in RAM mode) that would make BACKUP continue. But, on a CoCo with ON ERR GOTO, you can do something like this (of the top of my head, and no error checking):

10 CLEAR 1000:DIM SD,DD,T,S,S1$,S2$
20 INPUT "SRC DRIVE",SD
30 INPUT "DST DRIVE",DD
40 T=0:S=1
50 ON ERROR GOTO 130
60 PRINT "TRACK:";T;"SECTOR:";S
70 DSKI$ SD,T,S,S1$,S2$
80 DSKO$ DD,T,S,S1$,S2$
90 S=S+1:IF S>18 THEN S=1:T=T+1
100 IF T<35 THEN 50
110 PRINT "DONE"
120 END
130 PRINT"ERROR!":GOTO 90

That's more or less what I used to copy all my 35-track RS-DOS disks.

		-- Allen