ajparent1/kb1gmx wrote:
old analog monitors were pushing hard at 80 chars but crisp at 64...
at 64 chars most editors and apps were easy to live with, but less
tended to really suck...
I agree with your reminiscing, Allison. I have an Atari 800 with 32-char screen; its NTSC video is fuzzy and painful to read. I had an Osborne O1, and its 5" 50-char CRT was also poor. I had an S-100 64-char video card with 12" Ball monitor that was very readable. The Kaypro/4 9" 80-char CRT was decent, and my Heath H19/H89 12" 80-char CRT is probably the best of my antiques.
Modern LCD monitors are highly variable. Many have poor color NTSC conversion, with lots of artifacts and aliasing. But more expensive large-screen LCDs can be pretty good; they just get overly bulky (a 17" LCD is overkill for CP/M use).
before the CTRC part it was mostly TTL and a lot of parts.
Yes; brute force circuits. But by 1978-80, Lancaster, Wozniak, Sinclair etc. were showing us video circuits that used finesse and cleverness instead of brute force. That's the philosophy I'm after. How to produce good video without lots of parts or rare/expensive chips.
Graphics adds even more... not much graphics in Z80 CP/M applications.
Right. But today, people kind of expect/demand graphics. Most early systems that had graphics used "character" graphics; a special character set with graphicsh symbols. If my board can do this, it can emulate the screens of a TRS-80, Kaypro, Heath, VT-100, etc.
Since RAM is now cheap and it saves a character generator chip, I can make it a graphics display and "draw" the characters with the Z80, like the Mac did. I picked a 384x192 pixel screen for my Z80-VID design because it allows a 6x8 font to produce a 64-character by 24-line display, or even 80 x 24 with a proportional or ugly 4x8 font. This gives it a programmable font, to better emulate vintage computers, without "pushing" the NTSC bandwidth too far.
But... is all this reasonable? Would anyone build or use it? Or does it produce a display that nobody likes?
USB is easier to get PS2 is starting to get scarce.
Yep. But there are USB-to-PS2 adapters. That provides a path for the guy that wants to use his old USB keyboard.
Lee
--
A designer knows he has achieved perfection not when there is
nothing left to add, but when there is nothing left to take away.
-- Antoine de Saint Exupery
--
Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com
Lee Hart