RC2014 enhanced prototype board now on Tindie

July 19, 2019

I’m please to announce that the enhanced prototype board/PCB for the RC2014 Bus I blogged about back in May is now on Tindie.

Also it’s schematic is here.

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RC2014 enhanced prototype board

May 30, 2019

If you’re into making I/O cards for the RC2014 than this enhanced prototype board might be of interest to you.

It features circuitry (see schematic) to for selectable decoding the I/O address and also gates to generate !IORD and !IOWR signals, as well as two spare OR gates.

The IC’s used are:

74LS32 Quad OR gate
74LS688 Octal (8-bit) magnitude comparator


Apple II Prototyping PCB’s

June 29, 2018

I recently came into possession of a Apple IIe (an enhanced Apple II from the early 80’s) and decided to build a few PCB’s to help get this old warhorse back up in running. The first board  designed was an extender card for the Apples expansion card to make testing and fault finding them a little easier. The second PCB was a prototyping board to allow me to build up various test circuits.

 

Both will be available on Tindie soon


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 đŸ™‚ ) system.


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.