--- /dev/null
+4704 Keyboard
+=============
+Keyboard Models:
+ Model 100 6019273 50-key (grid layout)
+ Model 200 6019284 62-key Alpha(60% layout)
+ Model 300 6019303 77-key Expanded Alpha
+ Model 400 6020218 107-key Full key
+
+Resourse
+--------
+The IBM 4704: lots of pictures and info
+http://kishy.dyndns.org/?p=648#more-648
+
+Brochure:
+http://ed-thelen.org/comp-hist/IBM-ProdAnn/4700.pdf
+
+
+
+
+4704 Keyboard Protocol
+======================
+On powering up the keyboard sends keyboard id; A3h for 6019284(62-key), for example.
+After that firmware enters FC command mode and waits for parameter data from host
+so that it doesn't send any scancode until you send 'FF'(End of FC command).
+
+
+Keyboard to Host
+----------------
+Data bits are LSB first and Pairty is odd. Clock has around 60us high and 30us low part.
+
+ ____ __ __ __ __ __ __ __ __ __ ________
+ Clock \____/ \_/ \_/ \_/ \_/ \_/ \_/ \_/ \_/ \_/
+ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____
+ Data ____/ X____X____X____X____X____X____X____X____X____X________
+ Start 0 1 2 3 4 5 6 7 P Stop
+
+Start bit: can be long as 300-350us.
+Inhibit: Pull Data line down to inhibit keyboard to send.
+Timing: Host reads bit while Clock is hi.
+Stop bit: Keyboard pulls down Data line to lo after 9th clock.
+
+
+
+Host to Keyboard
+----------------
+Data bits are LSB first and Pairty is odd. Clock has around 60us high and 30us low part.
+
+ ____ __ __ __ __ __ __ __ __ __ ________
+ Clock \______/ \_/ \_/ \_/ \_/ \_/ \_/ \_/ \_/ \_/
+ ^ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ___
+ Data ____|__/ X____X____X____X____X____X____X____X____X____X \___
+ | Start 0 1 2 3 4 5 6 7 P Stop
+ Request by host
+
+Start bit: can be long as 300-350us.
+Request: Host pulls Clock line down to request to send a command.
+Timing: After Request keyboard pull up Data and down Clock line to low for start bit.
+ After request host release Clock line once Data line becomes hi.
+ Host wirtes a bit while Clock is hi and Keyboard reads while low.
+Stop bit: Host releases or pulls up Data line to hi after 9th clock and waits for keybaord pull down the line to lo.
+
+
+
+Scancodes
+---------
+Keyboard doesn't send Break code for all keys except for Alt by default.
+
+ 6019284 62-key:
+ ,-----------------------------------------------------------.
+ | `| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| -| =|???|BS |
+ |-----------------------------------------------------------|
+ |Tab | Q| W| E| R| T| Y| U| I| O| P| ￠| \| PD2|
+ |-----------------------------------------------------------|
+ |Ctrl | A| S| D| F| G| H| J| K| L| ;| '| {}| PD3|
+ |-----------------------------------------------------------|
+ |Shif| <>| Z| X| C| V| B| N| M| ,| ,| /|???|Shift |
+ |-----------------------------------------------------------|
+ |Reset|blk|Alt | Space |Alt |blk|Enter|
+ `-----------------------------------------------------------'
+ +----------+---------------------+----------+----------+
+ |` 00|PD1 04|Caps 20|LShift 30|Reset 31|
+ |1 18|q 05|a 21|<> 3E|Rblank 41|
+ |2 19|w 06|s 22|z 32|Alt 3F|
+ |3 1A|e 13|d 23|x 33|Space 40|
+ |4 10|r 14|f 24|c 34|Alt 3F|
+ |5 11|t 15|g 25|v 35|Lblank 42|
+ |6 12|y 16|h 26|b 36|Enter 2F|
+ |7 08|u 17|j 27|n 37| |
+ |8 09|i 01|k 28|m 38| |
+ |9 0A|o 02|l 29|, 39| |
+ |0 0F|p 03|; 2A|. 3A| |
+ |- 1F|￠ 1B|' 2B|/ 3B| |
+ |= 0D|\ 1C|{} 2C|??? 3C| |
+ |??? 0C|PD2 1D|PD3 2D|RShift 3D| |
+ |BS 0E| | | | |
+ +----------+---------------------+----------+----------+
+ Bit7 is 'press flag' which set 1 on press and 0 on release when break code is enabled.
+
+NOTE: When break code is enabled the key sends scancode with setting 7th bit on press
+and without it on release. That is, '`' sends 80h on press and 00h on release.
+
+
+keyboard command
+----------------
+ FF Soft Reset(0008h)
+ FE Resend(00e8h)
+ FD Buzzer stop?(00edh)
+ FC Set Key flag(00f6h)
+ FB Soft Reset(0008h)
+ FA Reset(0000h)
+
+
+Keyboard response
+-----------------
+ FF Not exist. [Outgoing buffer cannot have FFh(00h in fact)]
+ FE Overflow(key event/receive data) at 00c5h, 0346h
+ FE Memory test error at 0224h
+ FD Command out of bound at 00d8h
+ Key out of bound
+ 7E Read/Parity error in receive from host at 00bch
+
+
+Set Key flag command(FC)
+------------------------
+After 'Power on Reset' firmware enters this command mode and waits for data from host,
+so that you don't need to send 'FC' and it doesn't send any scancode until you send 'FF'.
+
+Data sent from host:
+
+ bit: 7 6 ... 0
+ en | |
+ | `-----`--- scan code
+ `------------- enable bit(0: enable repeat, 1: enable break)
+
+ 00-77 Enable repeat(78-7F: invalid scancode)
+ 80-F7 Enable break(F8-FF: invalid scancode)
+ FE Resend(011ah) no need to use
+ FF End(0114h) exits FC command mode.
+
+Response from keyboard:
+ FD Out of bound - Invalid scancode
+
+Examples:
+ To enable break code of all keys.
+
+ FC 80 81 ... F7 FF
+
inhibit();
}
+/*
+Host to Keyboard
+----------------
+Data bits are LSB first and Parity is odd. Clock has around 60us high and 30us low part.
+
+ ____ __ __ __ __ __ __ __ __ __ ________
+Clock \______/ \_/ \_/ \_/ \_/ \_/ \_/ \_/ \_/ \_/
+ ^ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ___
+Data ____|__/ X____X____X____X____X____X____X____X____X____X \___
+ | Start 0 1 2 3 4 5 6 7 P Stop
+ Request by host
+
+Start bit: can be long as 300-350us.
+Request: Host pulls Clock line down to request to send a command.
+Timing: After Request keyboard pull up Data and down Clock line to low for start bit.
+ After request host release Clock line once Data line becomes hi.
+ Host writes a bit while Clock is hi and Keyboard reads while low.
+Stop bit: Host releases or pulls up Data line to hi after 9th clock and waits for keyboard pull down the line to lo.
+*/
uint8_t ibm4704_send(uint8_t data)
{
bool parity = true; // odd parity
}
/*
-Keyboard to Host:
-Clock ~~~~___~~_~~_~~_~~_~~_~~_~~_~~_~~_~~~~~~~~ H:60us/L:30us
-
-Data ____~~X==X==X==X==X==X==X==X==X==X________
- | 0 1 2 3 4 5 6 7 P(odd)
- | LSB MSB
- Start bit(80us)
+Keyboard to Host
+----------------
+Data bits are LSB first and Parity is odd. Clock has around 60us high and 30us low part.
+
+ ____ __ __ __ __ __ __ __ __ __ ________
+Clock \____/ \_/ \_/ \_/ \_/ \_/ \_/ \_/ \_/ \_/
+ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____
+Data ____/ X____X____X____X____X____X____X____X____X____X________
+ Start 0 1 2 3 4 5 6 7 P Stop
+
+Start bit: can be long as 300-350us.
+Inhibit: Pull Data line down to inhibit keyboard to send.
+Timing: Host reads bit while Clock is hi.
+Stop bit: Keyboard pulls down Data line to lo after 9th clock.
*/
uint8_t ibm4704_recv(void)
{
projects / tmk_firmware.git / commitdiff