Džinova 8-bitová stránka
What is it ?:
- A new replacement of the MOS6581 and MOS8580 used in the Commodore C64. It is minimalistic (in simplicity of circuit and use, not in function and power).
- Real "plug & play" solution. Just insert instead of the original SID into the slot and it's done.
- It determines (through supply voltages) which chip it replaces and starts the appropriate emulation (it can be changed later in software).
- No need to switch the PAL / NTSC version, the circuit uses directly the clock from the computer bus, always synchronous with the C64.
- It also emulates analog inputs (joysticks, mouse, etc. - POTX and POTY inputs)
- Analog output is sufficiently buffered, it is not necessary to change anything on the computer board for proper operation.
- Output sampling frequency is 1/16th bus clock of C64 (approx. 62kHz), real 12bit D/A converter, no pwm.
- Filters completely transferred to digital form, emulated by float point arithmetic.
- Significantly lower noise level and less interference from the power supply than the original :)
- Lower power consumption than the original.
- Firmware update possible inside the C64.
What is inside ?:
- A few resistors, capacitors, one stabilizer, one opamp and a processor. That's all, parts only from one side.
- The only programmable circuit is the STM32F410, ARM Cortex M4 with HW float point arithmetic at 100MHz.
- Analogue output amplified via the AD8515 opamp.
- Stabilizer for the 3.3V processor, the processor itself has 5V tolerance inputs.
- Schematic in PDF here:
- Actual FW 1.12 from 12.1.2018 here or here zipped (if the file extension PRG is a problem).
- For the update, just upload to the C64, run it and follow the instructions.
- Emulates all waveforms, and even "samples" (at least some of them, Ghostbusters laugh, Chimera screams at you).
- Full support of analog filters (LowPass, BandPass, HighPass, combination, Q quality control).
- Emulation of OSC3 and ENV3 registers (little delay, approximately 16 clocks of the C64 bus).
- Joysticks and mice work.
- Configuration program is here.
- Screenshot from the configuration program:
- It is possible to change the emulated chip MOS6581 or MOS8580 or leave it on the automatic according to the supply voltage (set when the power is turned on).
- An example of the communication with the ARMSID here is a similar program list in Basic.