mirror of
https://github.com/holub/mame
synced 2025-10-05 08:41:31 +03:00
fix incomplete info (n/w)
This commit is contained in:
parent
85410f9a24
commit
2639397a9c
@ -68,10 +68,13 @@ Super Qix:
|
|||||||
|
|
||||||
The V1.1, V1.2 and US PCBS have two resistors from VCC to GND forming a
|
The V1.1, V1.2 and US PCBS have two resistors from VCC to GND forming a
|
||||||
voltage divider on top of 7H, the resistor from VCC/Pin 14 to Common is
|
voltage divider on top of 7H, the resistor from VCC/Pin 14 to Common is
|
||||||
22KOhms, the other resistor is unknown and seems to connect to GND/Pin 7.
|
22KOhms, the other resistor is also 22KOhms and seems to connect to
|
||||||
The center of the two resistors connects to one end of a 0.1uf capacitor,
|
GND/Pin 7. The center of the two resistors connects to one end of a 0.1uf
|
||||||
the other end of the capacitor connects to 7H pin 12.
|
capacitor and also to 7H pin 4, the other end of the capacitor connects to
|
||||||
This implies some sort of brief/reset pulse generation or filter on pin 12.
|
7H pin 12.
|
||||||
|
This implies some sort of brief/reset pulse generation or filter on pin 12,
|
||||||
|
or more likely some abuse of the TTL input hysteresis of the 74LS86 IC itself
|
||||||
|
such that transitions of pin 12 cause transitions on pin 4 as well, or similar.
|
||||||
Again, what exactly this accomplishes is unclear without further tracing.
|
Again, what exactly this accomplishes is unclear without further tracing.
|
||||||
|
|
||||||
- sqixb2 is a bootleg of sqixb1, with the MCU removed.
|
- sqixb2 is a bootleg of sqixb1, with the MCU removed.
|
||||||
|
Loading…
Reference in New Issue
Block a user