David Wilson wrote:
On Jul 10, 9:49 am, s...@alfter.DIESPAMMERSDIE.us (Scott Alfter) wrote:My II+ had a lowercase ROM installed when I acquired it. AFAICT, there were no mods to the motherboard needed to make it work. (It makes you wonder a bit why the II+ shipped with an uppercase-only keyboard and character- generator ROM...would an extra key for Caps Lock really have been that much more expensive?)
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Inbuilt lowercase - yes, but it is probably because of the keyboard. Starting a new, larger ROM would be expensive too if they couldn't use anything ready-made.If a lower case keyboard had been used you would have needed to add extra keys for [ \ ] ^ _ @ (some of which are available on the ] [ keyboard by shifting uppercase K L M N O P respectively [why not all of them I have no idea - I seem to recall that the keyboard encoder can do all six if the correct matrix cross points are chosen]).
To mention a machine that came at the same time, TRS-80, it too had only uppercase. There they did it to save a ram chip. Everything else was there, the character generator had lowercase and the keyboard did lowercase (you just couldn't see the difference...). It was normal to add a ram chip piggyback on one of the other static video rams and get the data bit in/out via straps. One cut was also necessary. Sometimes the original character generator wasn't suitable because you needed to have uppercase both in the 00-1F and the 40-5F area.
I have one TRS-80 model-I which still has this unsuitable character generator. It had the lowercase mod and in ROM basic it displayed gibberish, but running a DOS with a display driver fixed that. It would be possible to load a display driver also under ROM basic. I removed the lowercase mod. My old Video Genie, which is a TRS-80 model-I clone, utilize the 00-1F area of the character generator for other symbols (my own) and has a patched ROM so it doesn't affect ROM basic.
-- Knut (delete 'nogarbage.' for email)