I am sure most of us are familiar with Psion's "Horizons" as supplied
with the rubber keyed Spectrum all those years ago. It includes a "big printing" routine. Unfortunately this routine uses the first 16 bytes
of the ZX printer buffer as a data area. This renders the routine only
really usable on a 16 or 48K Spectrum.
Whereas I have an "improved compactness of BASIC" version of Horizons,
the "big printing" routine, even with extra space allowed for, seems
difficult to modify. Part of the program even seems to be used as a
table, so even if rewritten and placed lower still in RAM, with space
for data at the beginning, the original bytes would have to remain in
that area. The harder I try to resolve this, the more bizarre my
results.
Has anyone achieved a modified version of that routine that will work
on both a 16K and a 128 running in 128 mode? Has anyone analysed what
it's doing and worked out what needs to remain as it is? I have tried
but am just getting further from the expected result every time. I have
little doubt an alternative routine that works similarly could be done
for a 128, but what I am seeing when I work on the original is, to say
the least, extremely odd.
--
Phil Reynolds
mail:
phil-news@tinsleyviaduct.com
PLEASE followup news posts in news
Web:
http://phil.tinsleyviaduct.com/