This card uses a Hitachi 64180R microprocessor, which is a direct replacement for the Zilog Z180, which itself evolved from the Z80 microprocessor.
The card was made in about 1988 and is branded with Maple Enterprises. I have not found any information on this company. It may have been related to Maple Systems, which currently manufactures industrial computing equipment.
The processor includes two asynchronous communication controllers. Fortunately, this card has a serial monitor in EPROM. The monitor program is the 1010SC ByteWyde Systems. The ByteWyde monitor was customised for various systems. I was able to find a manual for a similar version.
ByteWyde probably also customised their BASIC for this board, but i do not have a copy of it. Sigh.
I have no documentation for the board itself, but it is clear that the card has a 16k ROM and 48k of static RAM. At one time the RAM was battery backed, but the battery has been removed. There is a little residue from the battery leaking which will need to be cleaned up. [I subsequently found a schematic in amongst some old notes.]
The memory space can be positioned on any of four 64 byte blocks. The monitor assumes that it is at 00 to 3F. I would probably need to change the base address on some cards to use this card.
I was able to work out the serial port pinout for tracing some signals from the processor. The board has a 20 pin footprint for the level shifters but the MC145406 only has 16 pins and is offset by two positions from pin 1. To further complicate matters the board has been modified P1-5 is grounded (not DCD) P1-2 is DCD (not 9V), P1-6 and P1-7 have been shorted so that RTS and CTS are connected on the board.
P1-3: Rx
P1-4: Tx
P1-5: Ground
After a little clean and re-seat the card came up fine. Serial port is 9600,8,N,1.
The manual for the Monitor mentioned that some commands require the use of a ByteWyde Hardware Debug Card. As it turned out i had one of those in amongst my cards. I suspect it will need a good clean before use.
