ASCII/CAPS LOCK

[smf]

On the international 128's the ASCII key controls different character roms & from what I've read it's just a wire from the rom to the keyboard.

Does anyone know where this is connected to? Or where I can find out ( without having to buy an international 128 ).

[wte]

ASCII/DIN (or ASCII/CC on other "localized" C128s) is connected to bit 6 of the processor port.
I don't know something about a second connection to a rom.

May be there is some info in the schematics on zimmers.net: ftp://ftp.zimmers.net/pub/cbm/c128/schematics

WTE

[airship]

WTE is right - it's physically connected ONLY to the 8502's built-in processor port in memory location 1.

The Kernal's KEYSCN routine sets bit 4 of location $D3 if CAPS LOCK is locked.

[hydrophilic]

I was suprised when I first used VICE and noticed the Charset would change by pressing CAPS-LOCK.  I soon discovered this was the International version and it had the ASCII-DIN in place of the CAPS-LOCK.

Suddenly I relized what had been puzzling me for years in the C128 schematic!  On the page describing the ROMs, there is a jumper that connects from U18 pin 21 to either the CAPSLK or 128/64 lines.  Well on the US version (CAPS-LOCK) this jumper is connected to the 128/64-line so the charset changes to original C64 charset for 64 mode, naturally.  But appearantly the 'International' C128 is jumpered to CAPSLK line (from ASCII/DEN key) so pressing the key changes the charset seen by VIC at the hardware level.  The International C128 must therfore use the same charset in 128 mode and 64 modes.

Well this is how I understand it from using the international version of VICE and looking at the schematics.  I only own a US flat C128 in reality.

See the schematics for U18, the 8008 character ROM in the C128 schematic.  Its in the C128 PRG but I don't know the page number (its near the back of the book).