@DC& 21 CC OR AF BE 21 D6 OB 3C
ODD@ 29 63 AL FB @B CD DE OD ba
@DDS CD 3E @@ C3 SR @C TE FE 96
@DEO 20 20 2 36 3G FE 39 20 EC
ODES OFT 36 3@ 2A CD DE OD C9 GE
ODFO 34 22 CS BF OG AM MB BB 25
G.M. Clarke, Edinburgh.
I am trying to understand the KBD routine in the T4 Monitor and can get so far
and then come to a halt! 1’11 pe.severe and get there but it strikes me that a useful
inclusion in the INMC80 issues would be a section on Monitor Software; a mits and
bolts break down of the routine. One section could be treated each issue or even
spread over two issues. I should be pleased if this suggestion were to be adopted and
would hope that others would benefit also.
Dave Pyke, Preston, Lancs.
NAS-SYS CAN CHECK SUMS!
Many thanks for the excellent newsletters I have received since becoming an
‘INMC80’ member. All the work put in by committee members is reflected in the
interesting and helpful articles and tips. For those of you with NASCOM 2s who have
been wondering how to print out check sums using the "TE" command (re Mr- D.- Tucker’s
program for Nasbug monitors in issue 5), try the following:
FEO8 UOUT : CP BS jsnote BS is 08 here (not 1D as for Nasbug)
37 SCF smustn’t set carry...
3F CCF ;...or Nas-Sys doesn’t jump to CRT routine.
co RET NZ j;no BS found so print the character
AF XOR A 3;zero accumulator
co RET ;CRT ignores NULLs.
Then activate the routine by storing its address for the jump vector SUOUT,
which is at address 0C77:
0c77. -cc3 80 OC SUOUT : JP UOUT
Now, to "switch on" the facility of ignoring backspaces (as produced by the
Tabulate command to delete check soms), type U. To revert to normal CRT output, type
I£ you are using Richard Beal’s "keyboard Repeater", then type in the routine
UOUT at address 0C80, and modify address OCA7 onwards as shown below:
OCA7 21 80 0C LD 4HL,UOUT
OCAA 22 78 OC LD (SUOUT+1),HL
OCAD DF 5B SCAL ZMRET
Now the vector at $UOUT, together with the keyboard repeat data, is loaded for
you when you type E0C90.
Rob Sheratt, Taynton.-