WonderMCA: Hardware and installation

This page shows you what is on the card, how to set its switches, how to install it and what to check before you switch the computer on. The microSD card is on 03-microsd-card-preparation. Updating the firmware is on 04-firmware-and-cpld-update. The overview is on 01-overview-and-features.

Warning. Switch the PS/2 off before you insert or remove the card, a microSD card, a jumper or a switch. The Micro Channel cannot take a card while it is powered.

The card

The WonderMCA board, revision 9, with reference letters
The WonderMCA board, revision 9, with reference letters
PartWhat it is for
ATC2050 pads (J20)For programming the CPLD with an external JTAG cable (Tag-Connect TC2050). Not needed in normal use. When you use a cable, the four JTAG switches (S) must all be off, or the processor can be damaged
BBOOT RP (SW1) and RESET (SW2) buttonsRESET restarts the card. Holding BOOT RP while you press RESET starts the RP2350 in its USB bootloader, for a firmware update through the USB-C port (I). Pressing RESET while the PS/2 runs pulls the card from under it, and the PS/2 usually hangs
CSWD debug port (J11, J14)A 3-pin connector for the Raspberry Pi Debug Probe, and the same signals on pins. Development only
DI2C: Qwiic connector (J5) and pins (J9)The screenpad connects here. Both carry the same 3.3 V I2C bus: SDA, SCL, 3.3 V and GND. The card’s clock chip is on this bus too
EUART console (J3)Console output: TX and GND, 3.3 V levels, 115200 baud, 8N1. The middle pin, marked X, is not connected: the console only transmits
FBattery holder (J22)Takes a CR1220 coin cell, + side up under the clip. It keeps the card’s clock running while the PS/2 is off
GW5500 Ethernet connector (J10)For an optional W5500 Ethernet module. The pinout is printed next to it. It shares pins with the WiFi module (L), so going from WiFi to Ethernet or back needs the PS/2 switched off and on
HBoard LED (D2) and LED jumper (J6)Blinks at start-up and during a CPLD update. Jumper on INT: the LED on the card. For a LED in the bracket, remove the jumper and wire the LED to the EXT pins: anode on the middle pin, cathode on GND. The series resistor is on the card
IUSB-C port (J4)Firmware updates only, with the card out of the PS/2. It also powers the card on the bench. Read the rules below
JAudio output (J15)3.5 mm stereo jack, line level. Connect powered speakers or an amplifier
KmicroSD slot (J12)Settings, disk images and CPLD updates, on a FAT32 card
LRM2 WiFi module (U11)Raspberry Pi RM2 module (CYW43439): 2.4 GHz WiFi for the network card emulation. It sits at the bracket end of the card
MUSB-A port (J7)USB host: keyboard, mouse, game pad, USB stick, USB Ethernet adapter. Its supply is current-limited
NMCA SND jumper (J21)Fitted: the card’s sound also goes to the Micro Channel audio line, which most PS/2 models play through their internal speaker. Removed: sound on the jack (J) only
OPWR WiFi jumper (J18)Powers the WiFi module (L). Remove it to switch the module off completely if you never use WiFi
PDEBUG pins (J8)Two spare signals (IN, OUT) and GND, for development. Leave them unconnected
QMicro Channel edge connector (J13)16-bit connector: the card fits 16-bit and 32-bit slots. Do not touch the gold fingers
RProbe headers (J1, J24, J23, J25)Every bus signal on labelled pins, for a logic analyser. Not needed in normal use
SJTAG DIP switches (SW3)Connect the RP2350 to the CPLD’s JTAG port for a CPLD update. All four off for normal use. All four on only for an update. On is towards the top edge of the card, as printed on the board
TCFG DIP switches (SW4)SW_CFG1 to SW_CFG4: DMA channel, data bus width and extended memory window. On is towards the top edge of the card

The DIP switches

The four CFG switches (T) are set by hand. “On” means the switch is closed. The purpose of each DIP may change on the coming release of the WonderMCA firmware, please read the release note carefully before upgrading.

SwitchOffOn
SW_CFG1DMA channel 1 (arbitration level 1)DMA channel 3 (arbitration level 3)
SW_CFG2Extended memory window code, see Memory
SW_CFG3Extended memory window code, see Memory
SW_CFG4Extended memory window code, see Memory
  • SW_CFG1 must agree with the DMA Priority you choose on the Reference Diskette: off with Level 1, on with Level 3.
  • memory errors at POST (error 201). The current firmware is the 16-bit build, so SW_CFG2 is on.
  • The 16-bit build moves extended memory about 1.7 times faster than the 8-bit build.
  • With no extended memory, SW_CFG3 and SW_CFG4 are both off.

Note. If you move one card between computers, set the switches, check the CPLD revision and edit config.txt again each time. See Memory.

Before you install the card

  1. Switch the PS/2 off.
  2. Check that the four JTAG switches (S) are all off. With all four on, the card waits for a CPLD update and the PS/2 does not see it. With some on and some off, the card stops with the red LED of the screenpad lit. The card does not boot while the JTAG switches are not off.
  3. Unplug the USB-C cable (I). Never insert the card with the cable connected. The USB-C port is only for firmware updates, with the card out of the PS/2:
    • it powers the card, so with the cable in you would plug a live card into the slot;
    • with the PS/2 off, the card’s logic would run from USB and drive the bus of a machine that has no power;
    • USB-C and USB-A (M) share the same USB lines, so a computer on the USB-C port would be a second host on the same wires;
    • it links the grounds of two computers.
  4. Never fit a jumper on the test pins marked 5V, 3V3 or MCA_5V with GND beside them. It would short the supply.
  5. Insert or remove the microSD card only with the PS/2 off. The card writes settings and disk images to it.
  6. Touch the metal frame of the PS/2 before you pick up the card. Hold the card by its edges. Do not touch the gold fingers (Q) or the chips.

Installing the card

  1. Fit the front and the back brackets. Take care with the WiFi antenna and the audio jack.
  2. Set the CFG switches (T) and check that the four JTAG switches (S) are off.
  3. Prepare the microSD card (page 03) and insert it.
  4. Check that the USB-C cable is unplugged and that the PS/2 is switched off.
  5. Plug the card into any 16-bit or 32-bit slot. Hold it by the top edge and the bracket, mind the WiFi module (L), and push it straight in. Screw the bracket.
  6. Connect the screenpad to the Qwiic connector or the I2C pins (D), if you have one.
  7. Boot the PS/2 from its Reference Diskette. Copy @DEAD.ADF onto the Reference Diskette first. A ready-made 1.44 MB image with the file already on it is available with the card files.
  8. Run Automatic configuration, or choose the settings by hand in Change configuration.

The adapter ID is 0xDEAD and the adapter name shown by the setup program is WonderMCA (1.0) by ViBR.

Settings offered by the Reference Diskette

SettingChoicesUsed for
I/O Address220h, 230h, 240h, 250h, 260hSound Blaster base port, by default select 0x220h
InterruptIRQ 5, IRQ 7, IRQ 3Sound Blaster interrupt, by default select IRQ5
DMA PriorityLevel 1, Level 3Sound Blaster DMA channel. Must match SW_CFG1
Joystick EnableEnabled, DisabledGame port at 200h to 20Fh

Note. The card’s logic answers the Sound Blaster at 220h to 22Fh only. Choose 220h. See Sound and game port.

Give each device its own interrupt. The card can deliver interrupts 3, 5, 6 and 7 only, by default the WonderMCA uses IRQ7 for internal interrupt and Network:

InterruptUsed by
3The serial mouse of the card (COM2), when USB Mouse is on
5 or 7The Sound Blaster (the Interrupt setting above)
5, 6 or 7The NE2000 network card (Network). Under OS/2 the NE2000 driver accepts 5 only
6The floppy controller of the PS/2

The serial port 2 of the system board

The serial mouse of the card answers at 2F8h to 2FFh (COM2) on interrupt 3. The Reference Diskette does not reserve that range. If you use the USB mouse, switch off the serial port of the system board that uses COM2 (Serial Port in the configuration of the PS/2). When both answer at the same address, the mouse is not detected, and some PS/2 models report a serial port conflict at POST. With USB Mouse on, the option ROM declares COM2 to the BIOS of the PS/2 itself, so DOS, Windows and OS/2 find the port although the system board’s port is off. See USB devices.

Note. USB mouse with the WonderMCA needs to disable the COM2 port on your chassis using the reference disk of your system. Please note that using automatic configuration, COM2 can be reactivated

Checking that the PS/2 sees the card

Press S at the boot banner and go to the POS Register page of the setup menu. It reads the configuration that the Reference Diskette wrote into the card: the slot, the adapter ID 0xDEAD, and the decoded settings.

The POS Register page of the setup menu: Slot 4, Adapter ID 0xDEAD, the eight POS bytes, Joystick Disabled, DMA Prio Level 1, IRQ 7, I/O Base 0x220
The POS Register page of the setup menu: Slot 4, Adapter ID 0xDEAD, the eight POS bytes, Joystick Disabled, DMA Prio Level 1, IRQ 7, I/O Base 0x220

If the page says No WonderMCA adapter found in any of 8 slots, the card is not configured: run the Reference Diskette again with @DEAD.ADF on it.

The POS Register page when the card is not configured: "No WonderMCA adapter found in any of 8 slots"
The POS Register page when the card is not configured: “No WonderMCA adapter found in any of 8 slots”

Resources the card always uses

ResourceRangeFunction
I/O388h to 389hAdLib (OPL2)
I/O250h to 253hCD-ROM interface
I/O2A0h to 2A7hCard command ports, used by the option ROM
I/O300h to 327hNE2000 network card and GUS
MemoryD0000h to D5FFFhOption ROM (D0000h to D3FFFh) and shared RAM (D4000h to D5FFFh)

No other adapter may use these ranges. The setup program marks a conflict with an asterisk.

The first power-up

  1. Switch the PS/2 on. The first time, the PS/2 reports error 165 (adapter not configured) until you run the configuration with the Reference Diskette. See Troubleshooting. Please note that some chassis will not loaded the boot rom of the WonderMCA without clearing the ERR165 (this is the case for most of the 95XX chassis)
  2. During the memory count and the adapter ROM scan, the option ROM prints its banner. The boot sequence is on the usage guide.
  3. If you fitted extended memory, the PS/2 reports error 164 (memory size changed) once. Run the automatic configuration again. See Memory. The banner of the card then shows one extra line, – Memory change : Reset the RAM Config., at the first start after the change.
The boot banner at the first start after a change of the memory configuration, with the line "Memory change : Reset the RAM Config."
The boot banner at the first start after a change of the memory configuration, with the line “Memory change : Reset the RAM Config.”

The screenpad

The screenpad is a small control panel. It has a 128 x 64 display, a rotary knob that you can press, four buttons (ENTER, UP, DOWN, RET) and four LEDs. It plugs into the I2C connector (D). It works with the case closed if you mount it in a drive bay or on the bracket. Without a screenpad, the card works: you do the same things in the setup menu or with wmctrl. The screens are on the screenpad reference.

The screenPad LEDs

The four LEDs, from the first to the fourth:

LEDColourMeaning
LED0redBlinks when an error is detected like disk image or a CD image could not be mounted. Steady on when a CPLD update failed or when the JTAG switches are in a wrong position
LED1greenDisk activity: on while the card reads or writes a mounted image
LED2blueNot used by the current firmware
LED3yellowA CPLD update is in progress

When the card starts, the four LEDs light in turn for half a second: that is the LED test.

Power

The card takes its power from the Micro Channel. The USB-C port also powers it, but only use it for firmware updates with the card out of the computer. The USB-A port feeds a keyboard, a mouse or a game pad; its supply is current-limited.


← Previous

Overview and features

Next →

The microSD card

WonderMCA user documentation Documentation home

Scroll to Top