Bits & P.C.s Basic Toolkit
Just one last item: since getting a 64k RAM card, I have been trying EPROM
based software in RAM and much of it works. However, some authors cannot resist
putting little “fixes” in their programs to prevent them from running in RAM. Now I
may be a bit naive, but I can’t for the life of me understand why they bother,
unless it is that they reckon EPROM based programs are harder to copy than RAM
based programs. Anyway, the Bits & P.C.s Basic toolkit is one of these programs,
and there seem to be three such “fixes”. To eliminate these, place zeroes (NOPs) in
the following locations BO20, BO21, B23E, B23F, B47, B248. If the program starts
on a different 4k boundary, change the B’s to the appropriate value.
I hope that some of the information above will be of interest to you and
your readers. Good luck with the magazine.
Clive A Graham G3XIG
BASIC Mods. & Microtype Cases
ee ee te ON A SS SS
As a user not used to machine code, it may seem dumb to suggest, but, how
about having all the readers rewrite the BASIC by offering their optimized Z80
solutions to the comprehensive listings of the 8080 codes available in the
Microsoft BASIC? It may well be that this is what Crystal has already done, but
knowing how well some of my better informed friends write in M--C, I have no doubt
that there has to be a better (or even best) solution to every one of the seven
hundred routines of the original Nascom BASIC, as well as to the forty-odd
additional general and DOS routines which I have seen added since.
If this were undertaken by a group of readers I feel sure that this would
be one of the largest and most interesting projects in microcomputing undertaken in
For those of us with Microtype cases for Nascoms 1 & 2, could I suggest
that someone makes an ‘extension ring’ to fit between the upper and lower halves.
Together with additional connectors there seems no reason why perhaps five or six
cards can not be fitted – the fan is quite large enough to cope, the only
limitation being the power supply which I believe could be uprated rather than
DH back again.
Yes, a nice idea, although I doubt that the whole readership would either
feel competent nor want to take part. This is the sort of thing that could easily
be handled within a group. It sounds like the sort of thing that NAS-TUG, the
Nascom Thames Valley User Group would dearly love to have a go at (how about it
Mike?). I might add that Carl Lloyd-Parker is something like half way through the
job of tearing the BASIC apart, converting it to Z80 mnemonics, commenting and
labelling it, so far he has 170K of commented source, and he says that’s less than
half of it. Personally I doubt that the finished code would be much if any shorter
as the Microsoft BASIC is the product of many man-years work and must be fairly
well optimized. Optimization to Z80 codes alone does not save all that much space.
If any readers feel like having a go, drop us a line. If we get more than one reply
we’ll put you all in touch.
The dear old Microtype case is fairly easily adapted and the idea of
producing a4 ‘skirt’ to fit between the top and bottom halves is a good one, if not
original. A couple of years ago I remember seeing one with the top and bottom
halves separated by 2" pillars and the resulting gap filled with fine black plastic
mesh apparently bought from an ironmonger.