Category Archives: Monsputer

Z80 Monsputer interconnect

This board does all the interconnect outside the bus connector. It has buffers to make ports 0x50 to 0x53 as tristate buffers. The circuit in the lower section converts ports 50-53 to hexadecimal for a VFD display. Advertisements

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Z80 Monsputer: CPU board

The Z80 Monsputer has of course a CPU. It went from several iterations of design over the years. This is probably not the last one because of the ugly patches. Z80 CPU running at 4 MHz 6850 main UART 8253 … Continue reading

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Z80 Monsputer GPIO and vectored interrupts

This board is one of the first boards I’ve done for the monsputer. It has only TTL logic on it. I’ve probably made it about 25 years ago (or more!). The chips came from a bunch of PCBs that I … Continue reading

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Z80 Monsputer memory card

This board has: 512k dynamic RAM 4 x 256k EPROM 2 x 128k FLASH 2 x 32k SRAM CPLD for glue logic The CPLD generates all the signals for refreshing the dynamic RAM. It also generates an 8th bit address … Continue reading

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Monsputer Serial Card

This card has several protocols: CAN (SJA1000) I²C (PCF8584) Serial (16550,6852) Parallel Port (CPLD) SPI (CPLD) External ports There are 2 CPLDs: ATF1504 parallel port ATF1508 SPI,vectored interrupts 10-1F, glue logic Here’s a look of the other side: I use … Continue reading

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Redone a previous board

A board that I made previously took too much glue logic and a multiplexing circuit was not working well enough so I decided to redo this board. 2 x 6850 UARTs with 8253 counter for baud rates 6840 Timer/Counter Dallas … Continue reading

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New board for the Z80 Monsputer

This board is a memory board that contain flash memories from old motherboards and old RAM chips lying around. A small CPLD does the glue logic. There is 7 x 128k flash memories and 3 x 32k RAMs.  

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