Nobomi has updated the ARMSID, which is a replacement of the C64’s MOS6581 and MOS8580, to version 2.8.

Version 2.8 updates include:

  • The start and the end of the bus data cycle (reading or writing) is now controlled by signal CS only (it was the same on the beginning of the cycle, but the end was controlled by 02 clock before), it can help with a bus stability in other systems than C64 a C128.
  • Internal frequency generators are updated with precision of one 02 clock – about 1us (no audio signal phase changes after frequency retuning) !
  • Correct polarity of the bandpass filter.
  • Added emulation of internal filter voltage offset.
  • Added the “Digi Boost” feature by software – an effect similar to adding 330kOhm resistor between EXTin and GND on the MOS8580.
  • Other speed optimization.

ARMSID