started to further break down the huge IMC-2001 main article

3 files changed, 94 insertions, 86 deletions

diff --git a/content/hardware/imc-2001-keyboard.md b/content/hardware/imc-2001-keyboard.md
new file mode 100644
index 0000000..aaeea43
--- /dev/null
+++ b/content/hardware/imc-2001-keyboard.md
@@ -0,0 +1,58 @@
++++
+title = "IMC-2001 keyboard"
++++
+
+connector to machine (sort of a rubber version of a DB-9):
+
+The connector on the computer side has a 9-pin DSUB connector male:
+
+```
+  +-----------    white  INTR
+  | +---------    black  GND
+  | | +-------    green  DATA
+  | | | +-----    blue   RESET
+  | | | | +---    Yellow CLOCK
+-------------
+\ O O O O O /
+ \ O O O O /
+  ---------
+   | | | +----    red    5V
+   | | +------    n.c.
+   | +--------    n.c.
+   +----------    n.c.
+```   
+
+On the keyboard PCB there is a strange white connector with the following layout:
+
+```
+    +------------- white   INTR (active low, after last clock tick)
+    | +----------- black   GND
+    | | +--------- blue    RESET (active low)
+    | | | +------- green   DATA
+    | | | | +----- yellow  CLOCK
+    | | | | | +--- red     +5V
+   +-----------+
+   |o o o o o o|
+   +-----------+
+   |           |
+```
+
+Keyboard layout:
+
+{{< figure src="/images/hardware/imc-2001/keyboard_front.jpg" alt="keyboard layout" >}}
+
+Keyboard has a 8039 CPU inside and a 2K EPROM:
+
+{{< figure src="/images/hardware/imc-2001/keyboard_pcb_controller_prom.jpg" alt="PCB and controller" >}}
+
+On the oscilloscope:
+
+{{< figure src="/images/hardware/imc-2001/oscilloscope_serial_keyboard.jpg" alt="serial keyboard signal" >}}
+
+The protocol is basically ASCII over 19200 baud serial, with an interesting end signal which
+IMHO triggers a latch on the motherboard or so (INTR white above).
+
+Broken keyboard cable (the black pins are just connectors added by me to test connectivity,
+both connector are female per default):
+
+{{< figure src="/images/hardware/imc-2001/keyboard_cable.jpg" alt="PCB and controller" >}}
diff --git a/content/hardware/imc-2001-power.md b/content/hardware/imc-2001-power.md
new file mode 100644
index 0000000..ee8e3a1
--- /dev/null
+++ b/content/hardware/imc-2001-power.md
@@ -0,0 +1,26 @@
++++
+title = "IMC-2001 Power and PSU"
++++
+
+Power connector on the motherboard:
+
+```
++-------------+
+| O O O O O O |
++-------------|
+  | | | | | +--- GND   black
+  | | | | +----- +12V  red
+  | | | +------- -5V   blue
+  | | +--------- -12V  brown
+  | +----------- +5V   white
+  +------------- +5V   white
+```
+
+Old PSU:
+
+{{< figure src="/images/hardware/imc-2001/old_psu.jpg" alt="New PSU" >}}
+
+New PSU replacing the old crusty one (this is a standard replacement PSU for
+Apple \]\[ from [Reactive Micro](https://wiki.reactivemicro.com/Universal_PSU_Kit)):
+
+{{< figure src="/images/hardware/imc-2001/new_psu.jpg" alt="New PSU" >}}
diff --git a/content/hardware/imc-2001.md b/content/hardware/imc-2001.md
index 2abdabe..d6a2cb5 100644
--- a/content/hardware/imc-2001.md
+++ b/content/hardware/imc-2001.md
@@ -2,11 +2,16 @@
 title = "IMC-2001"
 +++
 
-# IMC-2001
-
 This is an old Taiwanese Apple \]\[ / CP/M clone. 
 
-# Status
+## Subtopics
+
+- [Keyboard](/hardware/imc-2001-keyboard): keyboard connector and protocol
+- [Power](/hardware/imc-2001-power): PSU and power
+- [Chargen40](/hardware/imc-2001-chargen40): 40-column character mode
+- [Firmware](/hardware/imc-2001-firmware): the monitor, Applesoft ROMs
+
+# Status and unsorted stuff
 
 Trying to fix several issues:
 
@@ -15,7 +20,8 @@ Trying to fix several issues:
 - the 5V rail is on 4.5V now, causing issues with the keyboard (the
   length of the cable) and with the paddles. Not clear, whether this
   is the PSU (which is also showing 4.7V without load) or something
-  on the motherboard.
+  on the motherboard. There are two +5V lines on the original PSU and
+  only one on the replacement PSU, maybe that's a problem?
 - the keyboard beeps and issues '=' and '/' characters when connected
   to a longer serial cable, no problems when connecting the botched
   wire from the old connector on the keyboard PCB directly to the
@@ -152,32 +158,6 @@ The motherboard seems to be a CTAG-2 Taiwanese motherboard, so pretty standard.
 The floppy drives are standard TEAC-55A-U-00, with the short cable without the ground
 pins between data lines presumably.
 
-Keyboard layout:
-
-{{< figure src="/images/hardware/imc-2001/keyboard_front.jpg" alt="keyboard layout" >}}
-
-Keyboard has a 8039 CPU inside and a 2K EPROM:
-
-{{< figure src="/images/hardware/imc-2001/keyboard_pcb_controller_prom.jpg" alt="PCB and controller" >}}
-
-On the oscilloscope:
-
-{{< figure src="/images/hardware/imc-2001/oscilloscope_serial_keyboard.jpg" alt="serial keyboard signal" >}}
-
-Broken keyboard cable (the black pins are just connectors added by me to test connectivity,
-both connector are female per default):
-
-{{< figure src="/images/hardware/imc-2001/keyboard_cable.jpg" alt="PCB and controller" >}}
-
-Old PSU:
-
-{{< figure src="/images/hardware/imc-2001/old_psu.jpg" alt="New PSU" >}}
-
-New PSU replacing the old crusty one (this is a standard replacement PSU for
-Apple \]\[ from [Reactive Micro](https://wiki.reactivemicro.com/Universal_PSU_Kit)):
-
-{{< figure src="/images/hardware/imc-2001/new_psu.jpg" alt="New PSU" >}}
-
 # Documentation
 
 This is the "Operation Manual for IMC-2001, version 2.01":
@@ -192,64 +172,8 @@ This is the "Operation Manual for IMC-2001, version 2.01":
 I got a super serial card from Ebay, the documentation of it can be
 found here [https://archive.org/details/Apple_II_Super_Serial_Card_1981_Apple](https://archive.org/details/Apple_II_Super_Serial_Card_1981_Apple).
 
-# Schematics
-
-Power connector on the motherboard:
-
-```
-O O O O O O
-| | | | | +--- GND   black
-| | | | +----- +12V  red
-| | | +------- -5V   blue
-| | +--------- -12V  brown
-| +----------- +5V   white
-+------------- +5V   white
-```
-
-keyboard cable connectors:
-
-connector to machine (sort of a gummy version of a DB-9):
-
-computer has a 9-pin DSUB connector male:
-
-```
-  +-----------    white  INTR
-  | +---------    black  GND
-  | | +-------    green  DATA
-  | | | +-----    blue   RESET
-  | | | | +---    Yellow CLOCK
--------------
-\ O O O O O /
- \ O O O O /
-  ---------
-   | | | +----    red    5V
-   | | +------    n.c.
-   | +--------    n.c.
-   +----------    n.c.
-```   
-
-On the keyboard PCB there is a strange white connector with the following layout:
-
-```
-    +------------- white   INTR (active low, after last clock tick)
-    | +----------- black   GND
-    | | +--------- blue    RESET (active low)
-    | | | +------- green   DATA
-    | | | | +----- yellow  CLOCK
-    | | | | | +--- red     +5V
-   +-----------+
-   |o o o o o o|
-   +-----------+
-   |           |
-```
-
 # Links
 
-## Subtopics
-
-- [Chargen40](/hardware/imc-2001-chargen40): 40-column character mode
-- [Firmware](/hardware/imc-2001-firmware): the monitor, Applesoft ROMs
-
 ## Other IMC-2001
 
 * [Mention of the IMC-2001](http://www.epocalc.net/php/liste_models.php?texte=&look=All+fields&yearmax=2018&nocomp=pc&cat=Apple+2+clone):