With A Cherry on the Side – Episode Five (interrupts don’t happen at the worst possible time)

[A Project to interface a PS/2 keyboard to a 68hc11 microcontroller] Following on from the "final solution" plan described in the previous episode, the first step is to try to simulate incoming keyboard-clock interrupts. This can be done by using a pin of the output-only PORTB on the 68hc11 directly connected back to the input-capture … Continue reading With A Cherry on the Side – Episode Five (interrupts don’t happen at the worst possible time)

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With A Cherry on the Side – Episode Four (a plan for the nitty-gritty)

[A Project to interface a PS/2 keyboard to a 68hc11 microcontroller] The Nitty-Gritty At the lowest level PS/2 keyboard interface is an active-clocked packetised serial bitstream using open-drain drivers, running at 10KHz-30KHz (frequency depends on keyboard, and can vary somewhat at runtime!). The clock signal is "idle-high". The keyboard provides the clock-signal for both directions, … Continue reading With A Cherry on the Side – Episode Four (a plan for the nitty-gritty)

With A Cherry On The Side – Episode Three (terminal setup and more hardware)

[A Project to interface a PS/2 keyboard to a 68hc11 microcontroller] Get Cracking! So I have the target microcontroller SBC, and have verified it is still working. Today I have been setting up more project equipment. First off, I will need to be able to run my favourite simple command-line 68HC11 cross-assembler to generate loadable … Continue reading With A Cherry On The Side – Episode Three (terminal setup and more hardware)

With A Cherry On The Side – Episode Two (How to run code from non-existent ROM)

[A Project to interface a PS/2 keyboard to a 68hc11 microcontroller] The Case of the Unmissing PROM Last time, I mentioned that there was something a bit unusual about my 68HC11E1 MCU, running the BUFFALO monitor program from on-chip PROM. Well, the issue is that the E1 model 68HC11 isn't supposed to have any on-chip … Continue reading With A Cherry On The Side – Episode Two (How to run code from non-existent ROM)

With a Cherry On The Side – Episode One

It's kinda strange to be doing this in April instead of January, but as the RetroChallenge schedule has changed, it is time to get my plan together. Inspired by previous attempts, my modest entry to RetroChallenge this time is to interface a PS/2 keyboard to a 1987-vintage 68hc11 micro-controller; enough to at least read the … Continue reading With a Cherry On The Side – Episode One

Moving Targets Under Your Feet

An interesting (but unfortunate) situation with many softwares for Windows has come to my attention recently - a lack of control over development environments and packaging kits... There is still a lot of independant software out there that claims quite proudly to eg: "run on Windows XP, Vista, 7, 8 and 10". Unfortunately, much of … Continue reading Moving Targets Under Your Feet

Maxwells’ Silver Doofer: Dead in the Water

Count this as the┬ábiggest of big fails for Retrochallenge 01/2016... Maxwells' Silver Doofer just never really got going. January was way too busy with massive amounts of commercial overtime, attempting to swim a distance equivalent to a lap of the TT course (for charitable porpoises), sorting out personal tax affairs (jeez, the govt make the … Continue reading Maxwells’ Silver Doofer: Dead in the Water

Maxwells’ Silver Doofer: Episode 2: Reasonable Gratuitous Incompatibility

The Idris Users Manual is a tutorial-plus-reference-manual for "plain-old" users of an Idris system: Excellent tutorials on logging-in, how to enter commands, use of files and directories, text-editing, using the command-shell, and so on; plus reference manpages for the commmand-line programs, specific file-formats (password file, /dev/null, timezone, login-history file, mounted-filesystems list-file, etc); plus a system-administration … Continue reading Maxwells’ Silver Doofer: Episode 2: Reasonable Gratuitous Incompatibility

Maxwells’ Silver Doofer: Episode 1: How Not to Start a Project

Sheesh! January so far has been insanely busy with overtime at work, and if you add in the start of the Mens' hockey season and the first Firemans' Run of 2016, I am turning up a little late to this months' Retrochallenge event. My original intent was to get started 10 minutes after the start … Continue reading Maxwells’ Silver Doofer: Episode 1: How Not to Start a Project