1 IBM PC Keyboard Converter
2 =========================
3 The converter translates IBM PC keyboard protocols to use classic keyboards with modern computer with USB ports.
4 It supports both IBM XT and AT protocols, and all of scan code set 1, 2 and 3 with one firmware.
6 This is not finished project and still work in progress as of 2020-03-02. Test in the field and feedback from users are needed to improve firmware code.
8 You can discuss about this project here.
10 https://geekhack.org/index.php?topic=103648.0
13 This project is intended to integrated existent TMK XT, PS/2 and Terminal converters.
15 - IBM XT converter: https://geekhack.org/index.php?topic=94649.0
16 - PS/2 converter: https://geekhack.org/index.php?topic=14618.0
17 - IBM Terminal converter: http://geekhack.org/index.php?topic=27272.0
23 - PC XT keyboard of IBM 5150 5160
24 - 83-key: 1501100 1501105
25 - PC AT keyboard of IBM 5170
26 - 84-key: 6450200 6450225
27 - PC Terminal keyboard of IBM 5271(3270 PC)
28 - 122-key: 6110344 6110345 1397000
29 - 102-key: 1390680 1395764 1392595
30 - PS/2 keyboards(AT+CodeSet2)
31 - Clones of above models
37 Firmware supports ATMega32u4 and ATMega32u2 by default, Teensy2 or ProMicro can be used.
38 Wire controller pins below to keyboard signals, besides VCC and GND. This is compatible for Soarer's converter.
42 - Reset PB6 or PB7 (For some of XT keyboards. Not needed for AT, PS/2 and Terminal)
44 Pull up resistors of 1-4.7K Ohm on both Data and Clock line are recommended, without them it won't work in some cases.
47 Old Type-1 IBM XT keyboard and some of XT clones need this to reset its controller on startup. Many of IBM XT keyboards available are Type-2 and don't need the reset pin.
49 See this for Type-1 vs Type-2:
50 https://vintagecomputer.ca/ibm-pc-model-f-keyboard-type-1-vs-type-2/
52 As for clones Zenith Z-150 XT and Leading Edge DC-2014 are known to need this.
56 - http://www.kbdbabel.org/conn/kbd_connector_ibmpc.png
57 - https://allpinouts.org/pinouts/connectors/input_device/keyboard-xt-5-pin/
60 - http://www.kbdbabel.org/conn/kbd_connector_ps2.png
61 - https://old.pinouts.ru/InputCables/KeyboardPC5_pinout.shtml
64 - https://pinouts.ru/InputCables/KeyboardPC6_pinout.shtml
67 - http://www.kbdbabel.org/conn/kbd_connector_ibmterm.png
68 - http://www.kbdbabel.org/conn/kbd_connector_ibm3179_318x_319x.png
74 https://github.com/tmk/tmk_keyboard/tree/master/converter/ibmpc_usb
81 $ cd converter/ibmpc_usb
87 Keyboard discrimination
88 -----------------------
89 This section explains how the converter determines proper protocol and scan code set for keyboard. The converter need to do that before starting to receive and translate scan codes from keyboard.
92 After startup the converter sends 0xF2 command to get keyboard ID and sees how the keyboard responds to the command.
94 Response from keyboard:
96 - XT keyboard doesn't support any command and returns no response.
97 - AT keyboard should respond with 0xFA to the command but returns no keyboard ID.
98 - PS/2 keyboard should respond with 0xFA to the command, followd by keyboard ID, such as 0xAB86.
99 - Terminal keyboard should respond with 0xFA to the command, followed by keyboard ID, such as 0xBFBF.
101 Now we can dscriminate the keyboard and determine suitable protocol and scan code set as described below.
104 - Signals from XT keyboard are recognized by XT protocol.
105 - Signals from AT, PS/2 and Terminal keyboard are recognized by AT protocol.
108 - Scan codes from XT keyboard are handled as CodeSet1.
109 - Scan codes from AT and PS/2 keyboard are handled as CodeSet2.
110 - Scan codes from Terminal keyhboard are handled as CodeSet3.
116 Use hid_listen to see debug outputs from the converter.
118 https://www.pjrc.com/teensy/hid_listen.html
124 IBM PC Keyboard Protocol Resources:
126 [a] [Microsoft USB HID to PS/2 Translation Table - Scan Code Set 1 and 2](
127 http://download.microsoft.com/download/1/6/1/161ba512-40e2-4cc9-843a-923143f3456c/translate.pdf)
129 [b] [Microsoft Keyboard Scan Code Specification - Special rules of Scan Code Set 1 and 2](
130 http://download.microsoft.com/download/1/6/1/161ba512-40e2-4cc9-843a-923143f3456c/scancode.doc)
132 [1] [PS/2 Reference Manuals - Collection of IBM Personal System/2 documents](
133 http://www.mcamafia.de/pdf/pdfref.htm)
135 [2] [Keyboard and Auxiliary Device Controller - Signal Timing and Format](
136 http://www.mcamafia.de/pdf/ibm_hitrc07.pdf)
138 [3] [Keyboards(101- and 102-key) - Keyboard Layout, Scan Code Set, POR, and Commands](
139 http://www.mcamafia.de/pdf/ibm_hitrc11.pdf)
141 [4] [IBM PC XT Keyboard Protocol](
142 https://github.com/tmk/tmk_keyboard/wiki/IBM-PC-XT-Keyboard-Protocol)
144 [5] [IBM Keyboard Scan Code by John Elliott - 83-key, 84-key, 102-key and 122-key](
145 https://www.seasip.info/VintagePC/index.html)
147 [6] [IBM 1391406 Keyboard - Scan Code Set 2 of 102-key PS/2 keyboard](
148 https://www.seasip.info/VintagePC/ibm_1391406.html)
150 [7] [The IBM 6110344 Keyboard - Scan Code Set 3 of 122-key terminal keyboard](
151 https://www.seasip.info/VintagePC/ibm_6110344.html)
153 [8] [IBM PC AT Technical Reference 1986](
154 (http://bitsavers.org/pdf/ibm/pc/at/6183355_PC_AT_Technical_Reference_Mar86.pdf)
156 [y] [TrackPoint Engineering Specifications for version 3E](
157 https://web.archive.org/web/20100526161812/http://wwwcssrv.almaden.ibm.com/trackpoint/download.html)
159 [z] [Soarer's XT/AT/PS2/Terminal to USB converter](
160 https://geekhack.org/index.php?topic=17458.0)
166 ### Reset method for rescue
167 For converter without accesible reset button when magickey combo doesn't work.
169 Check pin status at powerup:
171 - if Data and/or Clock are pull down to GND
173 ### Force protocol and scan code set
174 Keyboard discrimination may fail and you have to configure them by hand.
176 ### Add AT90usb1286 support for Teensy2++