Yes, it's assembly. The resulting code that does very much the same was several times this size when I tried the C compiler. But the characters in the font varies from 1 x 5 to 5 x 5, so it does not have a fixed spacing. This way I can hope to get at least a minimal number of characters into a line. The printable characters in the font are packed together in just 192 bytes (no lower case).
Slowly I'm getting together what I need: The assembler, Visual Studio as editor, the emulator and also the new program to convert cassette tapes to binary or the other way around for new programs. I use the debugger I have for the old computer and run it in the emulator, together with the program I'm debugging. Fortunately the emulator can be configured to have some more memory.
Fixed width just does not work at such a low resolution. With a fixed 4 x 5 character matrix I could have 16 characters per line and 10 lines. But there are some characters, like 'M' or 'W' that just do not fit into a 4 x 5 matrix and there are quite a few that are actually smaller.
I have packed together two characters in one pattern, which makes the font so small. Even the little 8 bit processor can easily shift or mask out the correct bits before drawing the character.
Happily, the copy worked flawlessly, even though the playback was less than satisfactory... Oh well, I've learned that it's silly to expect a system to play back a recording at the same time it's recording the same stream. That's an important thing to know, and I'm glad I know it. Today, apparently, wasn't a complete waste - I learned something, and that's never a waste.
I realize that it's a bit tacky to drink Glenlivet from a glass labeled "Johnnie Walker" but is it, technically speaking, an actual crime?
A little background here... Last year I got a gift set of Johnnie Walker which came with two very nice glasses. This year I bought meself a gift set of Glenlivet, which was packaged with sample bottles of the 15 year old and the 18 year old, but no glasses. Later I bought my lady another set which had no samplers, but did include two very nice glasses. It turns out now that the set with glasses is only available at a store near her, and the set with samplers is only available at a store near me, and she wants the samplers. So we each bought a set for the other, which we intend to swap this weekend, giving us both nice glasses and samples of the finer versions of this fine concoction. But in the meantime, she's already cracked open my bottle at her house of the 12 year old, yet here I sit, having just put up a bunch of Christmas lights and craving a glass of the good stuff, but lacking a decent glass to pour it in! The Johnnie Walker glass is the best in the house, so to speak, until I can fetch my Glenlivet glasses from her house on Sunday.
Is there hope that I might be forgiven this transgression, under the circumstances? Or can I expect the Scotch police to come knocking in the wee hours and cart me off to some dark nether place where they serve only bourbon?
Your second paragraph, beginning "A little background here," would make a great opening for a short-story !
If it's crime, at least it's delicious crime ?
"We live in a world ruled by fictions: mass merchandising, advertising, politics as advertising, instant translation of science, technology, into popular imagery, increasing blur of identity in realms of consumer goods, preempting any free, original, imaginative, response to experience by the television screen. We live in an enormous novel. For a writer it's less necessary to invent a novel's fictional content: fiction's already there. A writer's task is to invent a reality." J. G. Ballard, 1974