148 lines
5.7 KiB
Plaintext
148 lines
5.7 KiB
Plaintext
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
|
|
|