prodos-drivers/README.md
2017-12-03 13:43:15 -08:00

2.0 KiB

The Cricket - ProDOS Clock Driver

I acquired a Cricket sound/clock peripheral on eBay. Therefore it is now critical that we have a conforming ProDOS clock driver for it.

STATUS: Works on my machine!

Background

"The Cricket" by Street Electronics Corporation, released in 1984, is a hardware peripheral for the Apple //c computer. It plugs into the serial port and offers a multi-voice sound synthesizer, a speech synthesizer, and a real-time clock.

The included disks include:

  • /CRICKET/PRODOS.MOD which can be BRUN to patch ProDOS in memory with a clock driver.
  • A modified version of ProDOS
  • A utility to patch ProDOS on disk

Goals

Like the NS.CLOCK.SYSTEM (by "CAP") ideally we would have:

  • A ProDOS .SYSTEM file
  • Detects the presence of a Cricket
  • Installs a driver in memory following the ProDOS clock driver protocol
  • Chains to the next .SYSTEM file (e.g. BASIC.SYSTEM)

Successfully tested on real hardware. (Laser 128EX, including at 3x speed.)

Build

Requires cc65. The included Makefile is very specific to my machine - sorry about that.

CRICKET.SYSTEM is the result of the build.

Notes

I ended up disassembling both NS.CLOCK.SYSTEM (to understand the SYSTEM chaining - what a pain!) and The Cricket's PRODOS.MOD and melding them together, adding in the detection routine following the protocol in the manual.

Other files:

  • GET.TIME just prints the current ProDOS date/time, to verify the time is set and updating.
  • TEST attempts to identify an SSC in Slot 2 and the Cricket via the ID sequence, to test routines.

Resources

Cricket disks on Asimov: disk 1 disk 2

Cricket Manual