swinkels
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- Birthday January 1
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SwinSID - a pin compatible alternative to the SID chip
swinkels replied to TheFumigator's topic in MIDIbox SID
Yes it is related to clock source and firmware, so you need special MIDIbox firmware to get proper pitch. PAL C64 uses 0.985MHz clock, so the firmware can't work with both sources equally. Unfortunately there is no MB firmware for TDA1543A but i will try to compile it for you. -
These extensions works only with special 'MIDIbox' SwinSID firmware version. Nevertheless your firmware is definitely much more close to real SID than the one reviewed by TK some time ago. It features e.g. ring modulation, improved waveforms and supports all filter modes.
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SwinSID - a pin compatible alternative to the SID chip
swinkels replied to TheFumigator's topic in MIDIbox SID
It seems that you are using wrong DAC chip version. Please test firmware for TDA1543A. This should help. -
Indeed, SwinSID emulates all SID filter modes without need of external capacitors.
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You're right. R3 jumper also changes output biasing. This was needed because older C64 boards has bit different output stage and I decided to simplify desing by adding jumper instead of a more complex but universal solution.
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@kristal=: Yes, because it is powered from 5V line only.
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Hi, I am the creator of the SwinSID and I can answer your question directly. There are two jumpers. First is used to setup output stage and volume, second is for filter selection between 6581/8580 model. There was special firmware version specially designed for MIDIBox with extended filter range but this feature is not enabled in standard release.
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SwinSID - a pin compatible alternative to the SID chip
swinkels replied to TheFumigator's topic in MIDIbox SID
Why not connect J14 to unused pin of J2? Anyone wants to build this new SwinSID PCB? I will help with programming and testing. -
I'm using simplified STK200 with success but heard that it doesn't work with some mainboards. STK200 doesn't need any power source but you AVR should be running while programming. Please post all further technical questions in this thread: http://www.midibox.org/forum/index.php/topic,9386.90.html Here You will find my tip with setting fuse bits.
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SwinSID - a pin compatible alternative to the SID chip
swinkels replied to TheFumigator's topic in MIDIbox SID
nILS, what is current status of your PCB layout? Is it finished yet? Small building tip: New AVRs are running with internal 1MHz oscilator. To use external 24MHz oscilator please set 'clock source' fuse bits to 0000 (all bits programmed). -
Check your fuse bits configuration to enable external clock source - AVR have to run with 24MHz. SwinSID plays short 1KHz test tone during startup, when the frequency is lower then your clock frequency is wrong. Are you using TDA1543, not TDA1543A? (TDA1543A won't work). If you still have problems, attach sound output recordings here.
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SwinSID - a pin compatible alternative to the SID chip
swinkels replied to TheFumigator's topic in MIDIbox SID
Yes they are swapped but no big deal. -
SwinSID - a pin compatible alternative to the SID chip
swinkels replied to TheFumigator's topic in MIDIbox SID
The master AVR is actually slave and vice versa. Both are ATMEGA8515, not AT89S8515 , therefore change their names to avoid confusion. -
SwinSID - a pin compatible alternative to the SID chip
swinkels replied to TheFumigator's topic in MIDIbox SID
There are in Poland for 1,93 euro http://tme.pl/katalog/index.phtml?f_szukaj=tda1543&idp=1 -
SwinSID - a pin compatible alternative to the SID chip
swinkels replied to TheFumigator's topic in MIDIbox SID
Thanks for the PCB. I haven't mentioned on my site that this schematic is for C64 version. It uses 74HCT138 for address decoding of each AVR from C64 bus. With MB we can remove this chip and connect CS signal directly to the MB core module as with MBSid - master CS goes to MBHP_SID:J2:SO and the second one to MBHP_CORE:J14.