[Coco] APPENDING TO A FILE IN RSDOS ?

[coco at jechar.ca]

To: All

I continue to have issues with file manipulation in RS-DOS.

My current objective is to add a 100 space characters to the end of a 
data file that consists of single byte fields.

So that given a file X on drive 0 running this program should create
a file PADDED.DAT on drive 1 who's contents are the contents of X:0 plus
100 blank spaces at the end of the file the following code fails I don't
understand what I am doing wrong.

To set things up you need a file "X" with no extension on drive 0 and
a File called SEED.DAT on drive 1. Then at the OK prompts type

OK DRIVE 1
OK RUN "PD.BAS"
FILE NAME? X

where the source for PD.BAS is shown below.

20 'A ROUTINE TO PAD THE DATA WITH 100's OF SPACES.
50 PRINT "FILE NAME";
60 INPUT F$
70 COPY F$+":0" TO F$+".DAT:1"
80 OPEN "R",#1,F$,1
90 MX=LOF(1)
95 PRINT MX;"BYTES FOUND."
98 PRINT"READY";
99 INPUT R$
100 CLOSE #1
101 'since I found no CREATE command I try adding to a single byte file'
105 COPY "SEED.DAT:1" TO "PADDED.DAT:1"
110 OPEN "D",#2,"PADDED.DAT:1",1
120 FIELD #2,1 AS DT$
180 OPEN "D",#1,F$,1
190 FIELD #1,1 AS ST$
200 FOR I=1 TO MX
210 :GET #1,I
220 :DT$=ST$
225 :PUT #2,I
230 NEXT I
235 J=MX+1
238 K=J+100
240 FOR I=J TO K
245 :DT$=" "
250 :PUT #2,I
260 NEXT
270 CLOSE #2
280 CLOSE #1
300 END

If someone knows an easier way that works in RS-DOS or what is wrong 
with
my code I would like to hear from you.

Charlie.