Program COMX35 side.
Run this program. Enter the bank number 0=0000-0FFFh, 1=1000-1FFF, 
2=2000-2FFF, 3=3000-3FFF.
At the end the sum of all peeked bytes is printed. Use this later 
to check the result at the other side.
Start the recorder. Enter "DSAVE". This saves the strings defined
in the program.

 10 INPUT "BANK 0 - 3 " S
 15 T = S
 20 S = S * 4096
 30 C = 0
100 FOR X = 0 to 255
110  A = INT(X / 16)
120  B = X - 16 * A  :  IF B > 9 THEN B = B + 7
125  IF A > 9 THEN A = A + 7
130  A$(X) = CHR$(A+48)+CHR$(B+48)+"0:"
140  FOR Y = 0 TO 15
150   P = PEEK(S + X*16 + Y)
155   C = C + P
160   A = INT(P / 16)
170   B = P - 16 * A  : IF B > 9 THEN B = B + 7
175   IF A > 9 THEN A = A + 7
180   A$(X) = A$(X)+CHR$(A+48)+CHR$(B+48)
190  NEXT Y
198  PRINT A$(X)
200 NEXT X
210 PRINT "BLOCK ";T;" CHECKSUM: ";C


# output with DSAVE
# string contents:
# abb0:hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh
# a  - block upper address 0-3
# bb - block lower address 00-FF
# hh - block data in hex

block (8k) checksum:
 0 = 553412
 1 = 499551
 2 = 504874
 3 = 508833


