umsmigie@ccu.umanitoba.ca (Jason Smigiel) (01/06/90)
I seem to have a problem with my keyboard, (on an Amiga 1000) If ever I have three keys pressed at the same time I get extra characters typed the most common is the sequence 'del' (it's only most common because I use 'del a lot in delete) When ever I type 'del' quickly I get 'delo'. I get this extra sequence for about half the 3 key sequnces I make. I know that the Amiga 1000 keyboard is desinged in such a way that this ghosting will occur BUT only if more than 10 keys are pressed. So what's the verdict is my keyboard dead? Or is this some quirk in a RAWKEY code conversion? Jason umsmigie@ccu.umanitoba.ca
jms@tardis.Tymnet.COM (Joe Smith) (01/14/90)
In article <1990Jan6.065639.23629@ccu.umanitoba.ca> umsmigie@ccu.umanitoba.ca (Jason Smigiel) writes: > I seem to have a problem with my keyboard, (on an Amiga 1000) If ever >I have three keys pressed at the same time I get extra characters typed >the most common is the sequence 'del' (it's only most common because I use >'del a lot in delete) When ever I type 'del' quickly I get 'delo'. I get >this extra sequence for about half the 3 key sequnces I make. > I know that the Amiga 1000 keyboard is desinged in such a way >that this ghosting will occur BUT only if more than 10 keys are pressed. Whoever told you it happens only after 10 keys is wrong. To quote from the Amiga Hardware Reference Manual, 1989 edition, page 247: The Amiga keyboard is a matrix of rows and columns with a key switch at each intersection. Because of this, the keyboard is subject to a phenomenon called "phantom keystrokes". While this is generally not a problem for typing, games may require several keys be independently held down at once. By examining the matrix you can determine which keys may interfere with each other, and which ones are always safe. Phantom keystrokes occur when certain combinations of keys are pressed simultaneously. For example, hold the "A" and "S" keys simultaneously. Notice that "A" and "S" are transmitted. While still holding them down, press "Z". On the original Amiga 1000 keyboard, both the "Z" and a ghost "X" would be generated. Starting with the Amiga 500, the controller was upgraded to notice simple phantom situations like the one above; instead of generating a ghost, the controller will hold off sending any character until the the matrix was cleared (releasing "A" or "S" would clear the matrix). You will notice that "D" "E" "L" "O" form the 4 corners of a parallelogram with the top slanted to the left. Pressing any 3 keys in this arrangement produces the 4th. -- Joe Smith (408)922-6220 | SMTP: JMS@F74.TYMNET.COM or jms@gemini.tymnet.com BT Tymnet Tech Services | UUCP: ...!{ames,pyramid}!oliveb!tymix!tardis!jms PO Box 49019, MS-D21 | PDP-10 support: My car's license plate is "POPJ P," San Jose, CA 95161-9019 | humorous dislaimer: "My Amiga speaks for me."
filbo@gorn.santa-cruz.ca.us (Bela Lubkin) (01/19/90)
In article <907@tardis.Tymnet.COM> Joe Smith writes: >To quote from the Amiga Hardware Reference Manual, 1989 edition, page 247: > still holding them down, press "Z". On the original Amiga 1000 > keyboard, both the "Z" and a ghost "X" would be generated. Starting > with the Amiga 500, the controller was upgraded to notice simple > phantom situations like the one above; instead of generating a > ghost, the controller will hold off sending any character until the > the matrix was cleared (releasing "A" or "S" would clear the matrix). Where is this controller? Is the one from an A500 compatible with the A1000 keyboard? I'd enjoy my A1000 keyboard more if it wasn't so prone to rollover artifacts. * Vote in progress: comp.sys.amiga.hardware; ends 1/22. See call for votes * * in news.announce.newgroups. Unambiguous YES/NO's to trent@ucscb.ucsc.edu * -- Bela Lubkin * * // filbo@gorn.santa-cruz.ca.us CI$: 73047,1112 (slow) @ * * // belal@sco.com ..ucbvax!ucscc!{gorn!filbo,sco!belal} R Pentomino * \X/ Filbo @ Pyrzqxgl +408-476-4633 and XBBS +408-476-4945