NM Documentation OK !
As anew member may I first of all congratulate the Committee on an excellent
publication which is both highly informative and yet very readable.
I would like to make a couple of comments. The first is with regard to the
criticism, by some of your correspondents, of the NASCOM-2 documentation. Having had
experience of the documentation supplied with other micros, I was absolutely delighted
when I received the NASCOM manual. Obviously it contains the odd error, or is brief in
places, but compared with other manufacturers” manuals I think it is to be commended
not condemned. It cannot be expected to be "all things to all users".
My second comment concerns possible future articles. I consider myself a
reasonably competent BASIC programmer and am slowly beginning to feel my way around
using machine code. However, my knowedge at the more technical side of the NASCOM is
very limited. Would it therefore be possible for someone to prepare a few ‘noddy’
articles on , say, general electronics (how does a decoupling capacitor work, tips on
using multimeters etc) and perhaps on certain aspects of the NASCOM design.
Finally, I read with a sinking heart the debate in your pages on running BASIC
without WAIT. I have difficulty running BASIC with WAIT! My system appears to have an
undocumented – ‘Trample-on and change string’ function. In large programs strings are
corrupted – particularly when involved in routines printing to the top line of the
screen. Result – the program eventually fails or, occasionally, BASIC crashes
completely. I do not think this is anything to do with the dreaded ‘Plague’ but I do
not have any idea where to start looking for a solution – has anyone else had this
Tan Irving – Thatcham, Berkshire.
ED – see elsewhere in this issue re. your “trample-on and change strings” problem.
LOAD Nasbug tapes into Nas-Sys
Other members who, like me, have upgraded from NASBUG T2 to NAS-SYS may find
the following program useful. It solves the problem of what to do with all those
programs that were saved on cassette using NASBUG, but won’t load under NAS-SYS.
It is an adaptation of the NASBUG cassette Load sub-routine, running under
NAS-SYS. One difference between it and the original -L’ Command is that it stores the
loaded programs at the header address + 1000H in order to avoid overlapping monitor
workspace and stack (this assumes some memory expansion, of course).
Additionally, the displacement of LOQOH makes it easier to modify the absolute
jumps, etc. that are necessary after re-location.
To use the load program, execute at 0C80, then load from cassette. The VDU
format and error-checking are as under NASBUG.
oc80 21 8A OB 22 29 OC CF FE
oc8s8 1D 28 FB FE 1F 28 03 F7
oc90. 20 F4 11 8A OB 06 08 1A
0c98 FE 2E 20 02 DF 5B DF 64
OCAO 2A 21 OC 7D 84 4F 3E 10
OCA8 84 67 E5 21 00 08 E5 ES
OCBO DF 64 23 7E El 77 23 81
ocB8 4F 10 F4 DF 64 23 7E B9
occO El D1 20 07 O1 08 00 ED
occ8 BO 18 B5 DF 6A 18 Bl 00
Paul de Bak, SWEDEN