Difference between revisions of "Keyboard"
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|PortMask=%xxxx xxxx ---- ---0 where only one bit in x is 0 | |PortMask=%xxxx xxxx ---- ---0 where only one bit in x is 0 | ||
}} | }} | ||
− | Reads keys on the keyboard depending on the upper byte of the port number. | + | Reads keys on the keyboard depending on the upper byte of the port number. The five keys are represented by bits 0-4 of the read byte, listed below with bit 4 first down to bit 0. A zero means that the key is pressed. |
{| class="wikitable" | {| class="wikitable" |
Revision as of 15:56, 29 August 2017
Number | $**FE |
---|---|
Decimal | |
Short desc. | Series of specific ports that read keyboard key presses. |
Bit Mask | %xxxx xxxx ---- ---0 where only one bit in x is 0 |
Readable | Yes |
Writable | No |
Subsystem | Input |
Reads keys on the keyboard depending on the upper byte of the port number. The five keys are represented by bits 0-4 of the read byte, listed below with bit 4 first down to bit 0. A zero means that the key is pressed.
Port upper byte | Keys affected |
---|---|
$7F | B, N, M, Symbol Shift, Space |
$BF | H, K, J, L, Enter |
$DF | Y, U, I, O P |
$EF | 6, 7, 8, 9, 0 |
$F7 | 5, 4, 3, 2, 1 |
$FB | T, R, E, W, Q |
$FD | G, F, D, S, A |
$FE | V, C, X, Z, Caps Shift |