prodos-drivers/cricket
Joshua Bell b621ac6a4d Add ROMX RTC driver, c/o Jeff Mazur.
This is a modified version of the ROMX Real-Time Clock driver. The changes include:

* Converting the source to ca65.

* Integrating with the driver installer framework.

* Adapting the driver to not modify page 2 beyond $220. The ROMX RTC
  firmware writes bytes to $2B0, and the the original driver placed
  temp code at $250. This can conflict with ProDOS applications that
  use page 2, so the driver was reworked to save/restore anything at
  at $2B0.

Other changes:

* Add a util/ source dir, and cricket/date, quit.system and
  pause.system there.

* Pull the "print current date" logic out of clock drivers into driver
  preamble.
2021-10-05 19:58:31 -07:00
..
cricket.system.s Add ROMX RTC driver, c/o Jeff Mazur. 2021-10-05 19:58:31 -07:00
Makefile Add ROMX RTC driver, c/o Jeff Mazur. 2021-10-05 19:58:31 -07:00
prodos.mod.s Unify inc/ directories 2019-10-03 21:23:00 -07:00
README.md Add ROMX RTC driver, c/o Jeff Mazur. 2021-10-05 19:58:31 -07:00
set.date.s Makefile tidying, unify headers 2019-10-04 18:10:01 -07:00
set.time.s Makefile tidying, unify headers 2019-10-04 18:10:01 -07:00
test.s Add ROMX RTC driver, c/o Jeff Mazur. 2021-10-05 19:58:31 -07:00

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 disks supplied with the device 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

CRICKET.SYSTEM

Like the NS.CLOCK.SYSTEM (by "CAP"), CRICKET.SYSTEM has these features:

  • 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, an Apple //c clone — 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 Utilities

These BRUNable files are also built:

  • TEST attempts to identify an SSC in Slot 2 and the Cricket via the ID sequence, to test routines.
  • SET.DATE sets the Cricket's current date.
  • SET.TIME sets the Cricket's current time.

Resources

Cricket disks on Asimov:

  • ftp://ftp.apple.asimov.net/pub/apple_II/images/hardware/sound/cricket_disk1.po
  • ftp://ftp.apple.asimov.net/pub/apple_II/images/hardware/sound/cricket_disk2.po

Cricket Manual on Asimov:

  • ftp://ftp.apple.asimov.net/pub/apple_II/documentation/hardware/sound/Street%20Electronics%20The%20Cricket.pdf

FYI...

In the Cricket manual there is a short sample BASIC program to set the clock without the use of any assembly routines, using PR#2 to talk to the serial card followed by PRINT statements. This does not appear to work from ProDOS with the clock driver in place - the time ends up temporarily scrambled until the clock sorts itself out again. Assembly language routines do work, however. I believe ProDOS attempts to read the clock during the execution of the basic program, which interferes the device.