New RC2014 boards: RS232 and 8052

April 24, 2018

I got a bumper box of PCB’s in the post today, just in time for Maker Faire UK 2018 this weekend (29th/30t April 2018).

Inside the box were some new RC2014 boards. The first two new PCB’s were my respins of a Z80 SIO/2 serial board and a Raspberry Pi Zero terminal board, as well as two brand new designs.

The first brand new board was a RC2014 RS232 breakout board allowing TxD1/RxD1 and/or TxD2/RxD2 serial signals from the RC2014 bus to be driven at RS232 levels.

The second brand new PCB was a new 8052 CPU board. This is a bit of an experimenters board as the 8052 bus architecture doesn’t directly map onto the Z80 bus architecture. When using the 8052 CPU some of the Z80 control bus signals (!M1, !MREQ, !IORQ etc.) will need pulling low via jumpers when attempting to make use of other cards. So why all the fuss. Well, the 8052 CPU does have the excellent the 8052-BASIC available which does make it a fun and a powerful (in 1980/1990 micro terms 🙂 ) system.

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RC2014 Prototype Board

February 23, 2018

The Prototype card is one of the very first cards I designed for the RC2014 system.

It’s larger than a normal RC2014 card but that is intentional so you have as much prototyping area as possible for building a circuit.

It features both the classic single row pin-header for the original RC2014 pin-out and also a double row pin-header for the newer enhanced RC2014 bus pin-out.

 

 

You can find them on my Tindie store


RC2014 Z80 System with enhanced bus

January 28, 2018

I’ve been busy with my big box of PCBs and I here’s my first Z80 system design and build. It comprises of the following:

– Z80 CPU card
– 8K ROM & 8K SRAM card
– 68B50 ACIA card
– 5-slot enhanced+ backplane

It’s pretty much a standard Z80 layout but I’ve expanded the bus to the latest Enhanced Bus definition for all the cards. The 5-slot backplane uses double row (2×39) female pin headers to include the RC2014 enhanced bus and in addition I’ve added an extra set of address lines (A16 to A23) for the possibility of using 16-bit CPU’s (8086/68000) and memory options (upto 1MB) in the future.

Here’s some pics of the various cards:


Z80 Card

Memory Card

 

ACIA UART Card

 


Big Box of PCB’s

December 27, 2017

Christmas came slightly early this year when a big box of PCB’s arrived.

Inside the box where a bunch of PCB’s for making guitar effects boards.

As well as a bunch of PCB’s for my take on a RC2014 Z80 based retro computing system.

More pics to follow when I’ve built them up.


Sick of Beige (SoB) board – RS232, 2-ch Relay and Prototyping board

February 25, 2017

Following on from last months post about my SoB DB9 breakout board I’ve design a few of more SoB breakout boards using the DP5050 footprint.

sb_relay2_small

The first is a 2-channel Relay Board. It has two relays with LED’s to indicate when they are active. Using it is pretty easy as it features the choice of screw terminals or pin headers to interface to it.

sb_rs232_small

The next is a universal RS232 breakout. I call it universal as all the pins (8 in total but not ground) from a 9-way RS232 DB9 are broken out onto pin headers. To connect up to these are the 4 signals (T1,T2,R1 and R2) from a MAX232 (or equivalent) RS232 chip. So you can swap around the transmit and receive and handshake signals as you like.

sb_protoboard_pcb_small

The next board is just a classic prototyping board. There’s not much too say about this board.

sb_sympsu_pcb_small

The last board is a symmetric power supply for rectify AC voltage into positive and negative DC supply rails. I’m hoping to use this for a audio project I’ve got in the works.

Dangerous Prototypes (DP) have a great page describing the various PCB sizes here:

http://dangerousprototypes.com/docs/Sick_of_Beige_standard_PCB_sizes_v1.0

As usual you can find them on my Tindie page here


Sick of Beige (SoB) board – DB9

January 9, 2017

Whilst looking to build some breakout boards I remembered the Sick of Beige (SoB) “standard” of PCB footprints designed by Dangerous Prototypes. DP have made a really cool set of PCB footprints in various sizes with the added bonus of being designed to be case friendly.

Dangerous Prototypes have a great page describing the various PCB sizes here:

http://dangerousprototypes.com/docs/Sick_of_Beige_standard_PCB_sizes_v1.0

sb-db9_2_small
My first Sick of Beige (SoB) board is SoB DB9, using the DP5050 footprint. This is a handy little breakout board for those wanting to build their own 9-way D-Type interfaces be it for RS232, RS485, CAN bus or any other project.

A standard 9-way D-Type (Male) connector provides the interface with 3.5mm Screw Terminals connections provided for easy interfacing. In addition a Male Pin Header connections is also provided. Two small circuit prototyping areas are also provided.

Board Details:

– 9-Pin D-Type connector (Male)
– Easy to Connect Headers
– 3.5mm Screw Terminals
– 2.54mm Pin Header
– small circuit prototyping area x2
– Compatible with Sick of Beigh DP5050 footprint
– Board Dimensions: 50 x 50 mm
– 3.2mm Mounting Holes x4

Uses:
– Industrial Control
– Robotics
– Mechatronics

As usual you can find them on my Tindie page here


Zero MIDI

December 26, 2016

A quick teaser for my next Raspberry Pi MIDI project: