3 ms·
> but the Alto would need to send the pixels a column at a time rather than a row at a time. That would be tricky to do Couldn't the buffer just be column-majo
by hcs 10y ago
> but the Alto would need to send the pixels a column at a time rather than a row at a time. That would be tricky to do
Couldn't the buffer just be column-major?
- kens 10y agoThe Alto could have used a column-major buffer and a sideways display, but that makes software more complex. For instance, text is in rows so its easier to render row-major. Using an 875 scanline display was easier - just change some resistors and capacitors in the monitor. (The exact resistors and capacitors are listed on page 36 of http://bitsavers.informatik.uni-stuttgart.de/pdf/xerox/alto/5-017-1017B_Ball_TTL_Series_Service_Manual_Oct76.pdf http://bitsavers.informatik.uni-stuttgart.de/pdf/xerox/alto/...)
- FullyFunctional 10y agoI'm equally puzzled by this. The complexity argument is IMO bunk; it's no more difficult. There is however a possible efficiency argument: if you are more likely to write horizontal rectangles of bitmaps, then you'd want the memory word to be horizontal so you have fewer memory locations to update. Was that really the case? UPDATE: I'm was using 2016 thinking, my bad. In those days, compared to the complexity of the rest of the system, making the CRT circuits custom was trivial. If this could, even marginally, simplify the rest of the system (not least the software), it would be the right choice.