Changes between Version 15 and Version 16 of geniuspc

Timestamp:

Apr 1, 2017, 4:25:25 PM (7 years ago)

Author:

pulkomandy

Comment:

--

geniuspc

@@ -18 +18 @@
 The ROM is a 16-bit one, available directly on the CPU bus. The FLASH is 8-bit, but directly on the CPU bus  as well. The cartridge port is connected to the same bus, and can be used for extra flash storage.
 
-Both flash chips (internal and cartridge) are 8-bit only. This means they can't be used for executable code.
+Both flash chips (internal and german storage extension cartridge) are 8-bit only. This means they can't be used for executable code. However, the cartridge port itself is 16bit and can be used for that purpose.
 
 The RAM is accessed through the VTech 27-05793 chip, which likely handles memory refresh.
@@ -59 +59 @@
 This means text is encoded in ASCII. Makes it easy to look for them in the ROM dump.
 
+== Cartridge port ==
+
+Finally the cartridge port is understood!
+
+To run code from there, you need the cartridge ROM (a 16 bit one) to start with "IQP QA TESTING PROG\0" or "IQ CART NOTV FRE 01\0" or "IQ CARTRIDGE FRE 01\0". The first string looks generic, but the two others (with FRE in the name) are likely specific to the French version, the other versions of the internal ROM should be checked to see what they expect.
+
+The NOTV variant seems to not output anything to the TV (possibly it is run before the video out is up and running). According to the MESS driver, there are several VTech machines whch share a similar architecture, and some of them are laptop-like with an LCD display, so that may explain it.
+
+The ROM jumps straight into the cartridge (at offset 0x14, just after the identifier string) if it detects a cartridge.
+
+=== Pinout ===
+
+||N.||=TOP=||=BOTTOM=||N.||
+||1 ||CARD1||GND||2||
+||3 ||D3||D11||4||
+||5 ||D10||D4||6||
+||7 ||D2||D12||8||
+||9 ||D9||D5||10||
+||11||D1||D13||12||
+||13||D8||D6||14||
+||15||D0||D14||16||
+||17||GND||D7||18||
+||19||+5V||D15||20||
+||21||+5V||A0||22||
+||23||A1||A16||24||
+||25||A2||A15||26||
+||27||A3||A14||28||
+||29||A4||A13||30||
+||31||A5||A12||32||
+||33||A6||A11||34||
+||35||A7||A10||36||
+||37||A17||A9||38||
+||39||A18||A8||40||
+||41||/OE||A19||42||
+||43||RESET||/WE||44||
+||45||/LDS||?||46||
+||47||?||A8||/CE||
+||49||CARD2||UDS||50||
+
+CARD1 = GND to detect fake-cart 1.
+CARD2 = GND to detect fake-cart 2.
+Both to GND to detect a real ROM cart.
+
 = Rom DUMP =
 
@@ -69 +112 @@
 
 I have started a MESS driver for this machine. Other people took a look at it and it's now booting, and allows you to use the machine : video, keyboard and mouse are working, as well as the flash memory chip. There is still no sound, and, as far as I can tell, no serial port emulated.
+
+== Memory map ==
+
+ * $300000 Video RAM
+ * $600301 Keyboard control (LEDs and stuff)
+ * $600801 4 for power on, 0 for power off