From 8b048532ecb9d7026af377236afa6b927b9526fa Mon Sep 17 00:00:00 2001 From: Thomas Daede Date: Wed, 26 May 2021 21:17:40 -0700 Subject: [PATCH] Update readme --- README.md | 29 ++++++++++++++++++++++++++--- 1 file changed, 26 insertions(+), 3 deletions(-) diff --git a/README.md b/README.md index 91190b4..94965e0 100644 --- a/README.md +++ b/README.md @@ -1,8 +1,27 @@ td-io is a JVS I/O board designed to adapt older JAMMA-compatible cabinets to the newer JVS standard, used by modern arcade hardware such as the Naomi and exA. It features a number of independent systems to translate signals, drive cabinet hardware, and power JVS games. +# Features at a glance + +* Chainable JVS I/O implementing a 2L12 panel and coin inputs +* JVS to JAMMA video converter compatible with all monitors +* Mono/stereo audio amplifier for driving JAMMA speakers +* JVS power connector providing 3.3V via on-board converter +* High reliability, low heat generation and all solid state caps +* Upgradeable firmware + +# Comparison + +| | TD-IO | Capcom I/O | Sega 838 | Exa I/O | +| ------------- | ------- | ------------ | ---------- | ------- | +| Lag (frames) | 0 | 1 | 0 | 0 | +| Chaining | ✅ | ✅ | ✅ | ❌ | +| Video | ✅ | ✅ | ✅ | ❌ | +| Audio amp | ✅ | ✅ | ❌ | ❌ | +| 3.3V power | ✅ | ✅ | ❌ | ❌ | + # JVS inputs -The JVS I/O bus connects to the board via USB-style A and B connectors. Daisy chaining is supported. The I/O presents two players, each with a single joystick/lever and six buttons. Joystick and button 1-4 inputs are mapped to the JAMMA edge connector, and buttons 4-6 are mapped to a CPS2-style kick harness connector. Buttons are polled on request, ensuring microsecond-level latency. +The JVS I/O bus connects to the board via USB-style A and B connectors. Daisy chaining is supported. The I/O presents two players, each with a single joystick/lever and six buttons. Joystick and button 1-4 inputs are mapped to the JAMMA edge connector, and buttons 4-6 are mapped to a CPS2-style kick harness connector. Buttons are polled synchronously, ensuring microsecond-level latency. Service, test, and tilt buttons are also supported. JAMMA's single service button is mapped to JVS player 1's service button. @@ -10,10 +29,12 @@ The board also presents one or two coin slots, toggleable by a DIP switch. The b # Video -The board amplifies JVS-level video (0.7Vp-p) to JAMMA appropriate levels, by applying a gain of 3. Amplification is DC coupled, so sources that swing negative will also swing negative on the output. Max input and output swing is -3.5 to 3.5V. +The board maps JVS-level video (0.7Vp-p, AC or DC coupled) to JAMMA levels (0-3V, DC coupled). This is achieved via a DC restore step using the sync signal, followed by a fixed amplification. The DC coupled output allows maximum compatibility with monitors such as the Nanao MS8 and capture devices such as the Splitfire which require it. In addition, a sync combiner combines negative H/V sync to negative composite sync. +No rate conversion is performed - the monitor must support the same scan rates as the JVS game. + An EDID EEPROM is also attached to the VGA port, to identify as a 31kHz monitor. # Audio @@ -22,7 +43,9 @@ A class-D audio amplifier provides high power speaker drive to the JAMMA edge. I # Power -An 8-pin JVS power connector forwards 12V and 5V from the cabinet to the JVS board. In addition, an on-board power supply generates 3.3V at up to 8A from the cabinet's 5V rail for systems that require it, such as Naomi. +An 8-pin JVS power connector forwards 12V and 5V from the cabinet to the JVS board. In addition, an on-board power supply generates 3.3V at up to 7A from the cabinet's 5V rail for systems that require it, such as Naomi. + +The cabinet's 5V power supply must still be adequate to power the 3.3V converter. The IO's electronics are protected from overvoltage and overcurrent by an automatically resetting protector.