Changes between Version 16 and Version 17 of geniuspc

Timestamp:

Apr 1, 2017, 8:47:05 PM (7 years ago)

Author:

pulkomandy

Comment:

--

geniuspc

@@ -59 +59 @@
 This means text is encoded in ASCII. Makes it easy to look for them in the ROM dump.
 
+The serial port is implemented by the small daughterboard above the mainboard. It uses a 4060 counter (baudrate generator?) and a GAL (shift registers?).
+
+There are some things involving interrupts happening, and since the interrupt is manually vectored (jump to register), if not properly setup it will crash both the serial port and the video logic.
+To avoid problems, the serial port is kept at a low baudrate (1200 bauds) by default, and set to 9600 only when the "chat" application is running.
+
 == Cartridge port ==
 
@@ -102 +107 @@
 Both to GND to detect a real ROM cart.
 
+== Sound ==
+
+There seem to be both a sample-based system (but the sample format isn't known yet), and a synthesizer system.
+
 = Rom DUMP =
 
@@ -116 +125 @@
 
  * $300000 Video RAM
+ * $600001 bit 7: set when Rx data available
+ * $600007 Serial port Rx data
+ * $600101 Serial port Tx (W) / Tx status (R)
  * $600301 Keyboard control (LEDs and stuff)
+ * $600501 Video control?
+ * $600600-4 Sample sound address
+ * $600605 Sample sound length (0xFF = about 1 second)
  * $600801 4 for power on, 0 for power off
+ * $600901-17 Sound synthesizer (TODO)