July 31, 2018
When design and building my recent RC2014 boards one of the things I’ve found most useful and fun to re-read them after so many years has been my collection of great old tech books and data books. You’ll probably recognise a few of them. Here’s a brief list in no particular order:
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
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.
March 26, 2018
Here’s a short list of serial terminal programs I currently use or I’ve used over the recent years:
RealTerm – my current favorite terminal program. Lots of features, including choice of binary display options: ASCII-only, Hex-only, ASCII + Hex. Send string shortcuts and so on.
TeraTerm – my previous favorite terminal program. There’s a new version, so I’m planning on trying out it for a while and see if its improved enough to replace realterm.
putty – a pretty standard serial terminal program that also includes SSH and Telnet clients.
muliterminal – as it names suggests you can setup many different terminals. I used it a lot on a recent multi-serial project where I could set up a configuration for each serial device in the project and save them. It save me time in only having to set up all the serial devices once so it proved its worth.
termite – is a very simple terminal program that just gets the job done
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
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:
ACIA UART Card