||i did some stuff on the new ultra303 prototype in the last days/weeks...and finally i've got a laserprinter at home that helps alot... so i don't need to go to work to print a layout...
i've thought much about if i release ultra303 or not... and well i've decided not to release it... so i can finish the ultra303 project this year and i can start with my new dsp based hardware project ;) i did much of research stuff for the new project in the last days ... friday ...weekend is near...! hurray
||just by accident i found yesterday the perfect cpu for my little hardware project...it has 48 i/o pins... enough to drive all 303 signals...without port extensions and stuff... that reduces the pcb complexity for the ultra303 much...
||finally... the self made pcbs are working quite good... i could perfect double sided pcbs with full thru connecion of all pins... that was a real hard job...it tooks me monthes to perfect that stuff..and it looks like this:
||greece was great... 11 days without computers.... really relaxing...no update for a longer time... i know ;) but i'm still trying to perfect my selfmade pcb's since weeks...it's a a bottomless pit...but it slowly seems to work quite good... so much new things to learn how do i create schematics with target... and how do i get the best result result after exposing and stuff... yesterday i did my first double sided pcb with full throught connextion of all pins... of course a good step for finishing ;) really interesting stuff in general...and beside this a good change from boring coding ;) unfortunately all takes a bit longer...well this is my first hardware project so i have to learn and find the best way to do it... before i can use it...time consuming...
||my vacation started 3 days ago...and tomorrow i'm off to greece for a while...
||i've got yesterday the new cpu's i've ordered for the firmware which is able to to handle isp (in system programming)...which means it's able to programm the cpu rom in system... so i can update the firmware via midi...but i have to change the bootrom of the cpu... normally the firmware is uploaded via rs323...no one really wants this...hm normally no problem but well i can't programm that cpu with my old cpu programmer to create a bootrom for it to load from midid ...but well don't work ARF... hmm
double ARF !!! i thought it is compatible to my old one hm...that's a real pain in the ass...so i have to find a different way to handle all...bla...just hearing snap ..."i've got the power..:" i hope i've got it too to solve all that stuff
beside this... the old cpu can only handle 32 kb bytes of firmware memory...i'm close to the limit of 32 kb...arf...hm did i said double ARF !!! already ?....but anyway.... at the moment i don't need 64kb for the firmware...so i can continue with the old cpu...sometimes i wish i had a arm cpu ;) sometimes i feel i have to reinvent the wheel...bla... sometimes for someone which is totally in in hardware business a hard job... but well...the new cpu can handle 60 mhz !!!...more than twice fast than the old one...so much more is possible...but as you can see much of problems...so stay tuned
||i did some research about rotary encoders today...and i've decided to include one... very nice to setup values,to navigate throu the menu or for example to change the step position in the note/time editor...very handy for the gui... i found a cheap one from alps cost 95 cent...really cheap...
||got midi to run again this morning at 3am...bla shitty bug...
i did some stuff for the syncing to the sequencer today... did some latency checks and well first test showed me 35ms latency...ARG...35 ms was really too much...but anyway this afternoon i had a closer look again...and *gg*...i forgot to remove from the midi routine the lcd test printing if something reached the 303 via midi...bla...after i removed this it was 7ms...that's quite good... i checked it agains the access virus and it has oeh round about 10-15 ms or so... here is the first test sequence synced to cubase:
->synctest.mp3 (945 kb)
and a picture how you build up your song...
as you can see...when you hold down a note in cubase...the 303 replays the pattern...the c-2 selects the first pattern...cis-2 the second...and so on...very like tb 303 emu audio realism... i liked that kind of handling...so i copied it ;) that means the track mode is not needed anymore when you decide to extent your song...you just shift the 303 notes in cubase and you don't need to change the trackmode from the 303...that saves time !
||much of bugfixes today... esp. like the random feature filled round about 200 bytes too much...stupid bug... reading and writing of patterns is working ok finally... shift left right is finished now...and added some shortcuts to jump to the first middle and last step of the pattern in the editor...extremly useful ...
but midi is still not working... i rechecked all source again...hm hardware is ok so far...but i have one idea left which i will check out tomorrow... i think i will skip the reverse pattern feature...i guess not very useful... but i've decided to add an insert and delete step during editing...that will be surely nice to have...hmm the edit menue is almost complete from that what i want to include in the first version... so i can start to include the replaymode ... i already have some ideas...the 303 is showing the note and efx during replay...i love flashing led's ;) but i really have to recode the led multiplexer...it's just sick at the moment... so let us hope tomorrow it will be rain day...otherwise i have to go to the beach ;)
||i did much of minor bug fixes today... included the pattern shift feature from the edit menu... and changed some stuff in the gui... and tested a bit... hm seems pattern read and writing has a bug... sometimes...anyway
time to do a todo list to see what is left...
i bought a 606 at weekend...maybe a future project ;)
||the new eeprom is working now... but midi is not working again...odd stuff...anyway too tired from badminton to figure it out now...;)
||did some smaller changes today...all is working fine again...and some source cleanup...but not motivated to include the new eeprom now...;)
||i did some bigger changes to the source yesterday...to make it more flexible...also some porting and stuff but this should be finished today...so i can continue the main work... but hm the assembler i'm using drives me mad at the moment...i wish i had an ide like mlap from microchip... i wasted nearly 2 hours to reproduces a bug...the #ifdef #endif feature seems not to work how i expected...or better it doesn't work at all ;) that's oerks...anyway well batronix mc programmer are nice...but the software for it is well not the best one... for example... mostly you build up your source code with sub sources which are included...the subsources can include other sources again it's something like a source tree...so when a bug is in a sub source... i only can see ...well there is a bug...but i can't see where in which sub source file or the line number...that sometimes take years to figure out where is the bug... or not macro support... today during raving i thought to myself maybe a good time to change the assembler now...
||in the last days i tested much with doing pcb's by myself and stuff...so no direct code for the firmware... but i've got my new eeprom on friday...so i can finally include it...
||i tested a bit with pcb layout prgs the last days... well to be honest...i really hate eagle from cadsoft...but i think i will use target 3001 to create my pcb's... really handy to use and bla... ;)
|| yesterday i started to implement the transpose up feature for patterns...hm but wasn't very productive...somehow i was mega tired and it didn't worked in the end...ok now it's clear why i didn't work...so i hope i can finish it today...
|| finally i did today the needed bigger change for the internal pattern format.. that feature i'm shifting since hm i guess 2 weeks or so and was done in 30 minutes ;) dunno hard to motivate at the moment...;)
but now i have 2 additional bytes for every note...so i can setup 2 velocity values or so for each... all was changed ...pattern reading writing...and all functions from the edit menu...ok the online editor is not changed yet...anyway no movtivation to do this now ;) maybe tomorrow...
somehow the sequencer wobbels at the moment...hm dunno strange...i will check tomorrow if the old source version wobbles too...so surely no bigger problem...
|| i did some planning today...and changed the handling of the gui a bit...i think now it's more intuitive to use...hm i really need to do that bigger change of the internal pattern format...otherwise i don't need to start with the dco stuff..oerks... most impressive thing was today my total lazyness ;)
|| well... i included as you maybe know a dac some days ago for the filter velocity...today i could not resist ;) when i came back from work i did a copy of the current source...did a small timer and did a small waveform via the cpu connected it to the 303 and well...and it works !... i just had to test this ;)
->tb303_dco.mp3 (711 kb)
ok i know not impressive...but cool...so it really seems to work how i planned to do the digital osc ;) i was not sure about how can i feed in the new generated wave into the tb 303...well i'm no analog freak... but i found the right point to feed in...
but of course...the other stuff is more important... so this was just a small test and will be continued later... but good step today...;)
|| midi is working again...after an endless search i finally checked if the midi cable is working...and it didn't...bla... that was really stressy...
so i could contine the filter velocity today... esp. i added the filter velocity to the online editor and so on... but something is strange...somewhere is a bug... when i let a led flash via the filter velocity it's not the same i set up in the editor...hm that's really odd... anyway... for the filter velocity i have to change much ...the internal pattern format and so on...and hm of course all routines which are accessing the patten...also the edit features...stressy...dunno why i didn't do it from the beginning...a good job for the weekend ;)
firmware is now round about 26 kb long...so 6kb left for code...otherwise i'm running into problems ;)
3301 lines of code
|| i did yesterday the dac code for the filter velocity...added some lines to the sequencer to check if it's working...and seems to work ;) i recognised the filter control is logarhythmic ...hm so i have a to do a convertion table...that's stressy... and dunno why ...hmm the midi interface don't work anymore...bah i hate that...but i could not figure out what's the problem till now...anyway maybe i can find it today...
|| i'm working out the filter velocity at the moment...i think i can include it in the next days to the test pcb...
the hardware is done now for the filter automation/velocity...but not tested yet...the software part is not done...but too late now have to catch some sleep back cause of yesterday ;) hm i really need to note down the schematics...otherwise i forget the most ...but stressy work
|| cool... pattern select via midi is working...so i could use the new firmware to do for the first time music...ok didn't do something serious...but cool it works ;) so even after a drop out from cubase the 303 is syncronized after the next bar... good to work with... first i had mega problems... it didn't synced ok...and i thought hm maybe the timer accuration isn't good enough...the problem is u never hit the bpm speed for 100%...it's always a bit slower or faster...but in the end it was so stupid...the sequencer ran on 135 and the 303 on 140 bpm...hell aua...anyway with correct bpm count on both it syncronizes pretty cool...
so today was a good break thru...the firmware is getting slowly usable now...;)
|| i included today the second syncmode...via internal bpm timer...works fine so far...so i only have to include the pattern select via midi and i can do my very first song with the new firmware ;) great ...maybe i can finish that thing today...
damn...euro 2004 soccer leeches too much time...;)
|| the eeprom problem is solved...puh... so i can continue now...
pattern read and writing to the eeprom is finished...
included some features from the edit menu:
pattern copy 8->16
pattern copy 4->16
pattern copy 2->16
and some bugfixing in the random pattern feature...
finally i checked the difference between my and the rebirth sequencer... and it really seems rebirth is different here from the original...when you do two notes ...on the first one is a slide on the second an accent... in rebirth the accent is played...on the original not...so my sequencer is ok...fine
|| today i had a nice idea for a new feature in the edit menu...i was thinking about the random pattern feature...and well you know that you create a random pattern and it does not fit into your chords... so the idea was to create a feature which fits a pattern into a key tone like c-dur...so you don't have disharmonic notes anymore...another feature would be a harmonic shuffle...which shuffles the existing notes in a way that it always fits into the tone key...
|| hm...somehow the eeprom seems not to work anymore...i already changed the eeprom/cpu and switched back to a backup of the sources...but it still don't work...that's odd... hm maybe i can find it later what the problem is...strange is it didn't work anymore from one day to another...so it must be a hardware problem...hm
|| i was a bit bored at work today...so i coded the routines for the vco replacement... to interpolate, mixing and clipping waveforms... i was a bit surprised worked very well so far... so now i'm able to generate multiple osc's on my cpu...i only need to add a d/a converter and i could start with the vco replacement...but the other stuff is more important...that was just to see how fast interpolation and mixing/clipping will be...and it's quite fast ;) of course a polyphonic tb 303 would be possible...but it would have only one filter/vca...i guess that's quite senseless to include polyphony then...
|| i finished today the random generator...niceness... i recorded a bit of the stuff the 303 replayed during i was testing the random generator...did some bugfix too but mainly i tested the firmware today...works really nice so far ;) get the testtune here:
->dreh303.mp3 (3,3 mb)
it starts a bit boring...you will hear the standard 1/16 c pattern...but later it gets more and more complex...very good to hear the possibilities of the random generator...first i create slide...then accent ...up and down...and finally notes...and so on ...in the end i just generating all jumpled...this is only one pattern...at the moment i only can replay one pattern but that will be changed tomorrow
i love that kind of noises ;)
|| i finished today the time editor...and i changed the pitch mode again...now it shows previous current and next note...that's much better ...but i'm now able to edit an entire sequence on the tb 303 with my own firmware...that's a great and important step...;)
so i started to include the features of the edit menu... i included:
Init 1/16 C
and at the moment i'm working on the random pattern generator...hey that's crazy stuff which comes out of the generator...really funny to play with....nice half an hour i'm just pressing the randomize key and playing with the generated patterns...;) the random pattern generator is a bit more complex than normal ones... you can setup what should be randomized...means you can only let the generator ramdomize the notes...or only slide or accent and stuff or all...anyway how you need it...it's possible to randomize parts from the sequence...means for example when your randomized sequence is cool but the last 4 notes are crap...you just can generate 4 notes...
but great... all is working really good at the moment...no bigger problems...when it continues like this i guess i can do my very first song next week with the new firmware... but for this i finally have to include pattern reading and writing to the eeprom...at the moment i just use the internal memory from the cpu...but that's no big deal...
|| the problem with the swiches which were pressed by ghosthand is gone now...i just checked my idea i had yesterday night...and it was really the problem i thought of...so next will be the time mode...at work i was thinking about ...maybe it's an good idea to include the time mode itself but also a possibility to change the time in the pitchmode...for example by clicking the bar key and for example note on/off and stuff...that would make things a bit easier...i mean otherwise you always have to switch between the pitch and time mode...hm i will include both to see what is the better way to edit....
beside this i browsed a bit and searched for port i/o expansions via i2c bus...and hm seem i will change the in and out ports later to i2c bus ic's...the main reason for this is i can't do two layered pcb's or hm never did it until now...without i2c i have to do much of cables to connect and bla...that's time consuming to finish a pcb...
|| the pitch editor is working so far... even with editing of notes accent slide up and down...funny to play with... never could edit that part of a 303 sequence that comfortable...of course the online pc editor is more comfortable but anyway...but to edit the sequence on the 303 itself niceness... while testing the editor i recognised...it's better to display the current previous and next note...not the next two... esp. for slides and stuff it's more interesting to know what was the previous...but there is really a small problem...sometimes keys are pressed by ghosthand.. i but only during the sequence is running... but i already have an idea what the problem could be... i will check tomorrow.
heavy...the new firmware is already 16,3 kb long...i thought 8 kb will be surely enough...of course the menu texts blowed up all a bit...i mean 5 days ago it was 8 kb... hm so i have to use the more expensive cpu with 32 kb flash code memory...there are many of features missing...like the entire edit menu and stuff...but anyway the cpu costs 7 euro...instead of 1.93 euro ...so no real problem ;)
|| nearly all memory variables are now shifted to another memory position...and suprise all crashes are gone now...that's cool...so i could continue the internal editor today...
i'm slowly getting an idea why the tb 303 internal editor is that cryptic...for example why you have to hold down the "next" button to edit accent slide up and down in the pitch editor...it's just because of the hardware...the problem is the leds are controlled via a matrix ...means for example when the c led is on and you try to switch slide on too...the down led with light too...because of the matrix...when you press down "next" there is never the note displayed...because of that...so i really have to change some things in editing...because i never liked that pressing "next" to edit the efx...with old switches it often jumped one or two note and bla...so the accent slide up and down led will not be used in my editor...i will display the current note and the up down slide and accent via the lcd display...beside of the current the next 2 notes with efx will displayed too... hm that makes editing a bit easier...of course not the real 303 editor...but anyway i think it's really the better way of doing this... but nice i already can browse thru the pattern...so tomorrow i can include the editing of the note...
and well...that idea of the vco replacement is getting more and more interesting...i already did some test and seems not to be that hard... if the vco replacement will be done with a second cpu...one cpu only for the vco... i'm planning to do 3 vco's with sub vco and stuff...that should be possible with 24 mhz... in the past i did already a bigger music programm with synthetic sound creation...that helps alot here ;) i already thought about to include a sid (c64 soundchip) as a vco...it has 3 independant voices...but hm an own vco cpu is of course more flexible...
|| i started today to shift the memory variables to another position to get more space for the stack... bah... really much work and esp. really annoying work...and all this stress just to save round about 60 bytes! for the stack area...hell i'm having 1 gb in my pc and have to fight here with 60 bytes... ;)
|| updated the site a bit esp. i uploaded the planned userinterface
i added today the memory to the test pcb and coded the routines for accessing the memory via i2c...works fine...;) unfortunately i only have a 24c16 here and of course on sunday all shops are closed...the 24c16 has only 2kb of memory...anyway should work for the first steps
so it's time now to create the resistant system prefs memory map...like midi channel and so on...
the user interface is slowly getting to work... i started to code today the internal editor...but i'm really slowly running into memory problems...i planned to use the first 128 bytes for stack and memory variables...but hm sometimes it crashes...the stack runs into the memory variables... that's bad...ARF
so i have to shift the memory variables to a different memory pos...that's in general a problem with the cpu i'm using...it has 512 bytes of memory...but you can't access them all with the same assembler commands...which means i have to recode some stuff to shift it to another memory position...shit... maybe i should have used another cpu...for sure ...the last project i'm doing with this cpu...
i already thought to change it...but i guess it's too late now already 1800 lines of code...maybe i can drop down the stack usage a bit...
|| i had some thoughts today which root menus and menu entries i will need and noted it down...what informations will be displayed and where...which swichtes will be used and stuff...means the entire look and feel...i decided not to add some additional switches to navigate thru the menusystem...it's not needed...ac and sl will be used to select the menu entry...up and down to change values...next to proceed a feature...back to return to the root menu...so nearly perfect...;) after all planning i started to code a the menusystem...and it's working already...
next will be to include the:
hm the entire firware is already over 8kb and 1400 lines of code...heavy...8kb assemblercode ;) i didn't expected it will be that long...anyway
|| the switchboard services routines are done...even run/stop ..pattern/mode select is working...nice
|| yesterday i studied a bit the i2c bus for the memory implementation...i think i know now how it works...beside this i discovered again a unique behavior of the old 303 sequencer...but didn't checked what it's excatly...
finally i could find the problem with the switchboard...puh... i had some sleepless nights because of that...but in the end... it was just a small bug...hell was that stupid ... anyway ...i started now to code the service routines for the switchboard switches...nearly finished ...
that was the last bigger problem...niceness...so i can start at weekend to implement the user interface for the 303 itself...
hm i had a new idea for a mod...while i was studying the schematics again...a vco mod...i thought myself why not to replace the vco too...ok it would be a digital vco then but anyway...that would open up totally new possibilities...of course the old vco would be still available...anyway just an idea ...we will see ;)
|| finally the problem in the sequencer is gone... now all sounds how it should...;) that's nice ...also continued the rebirth reader a bit and checked most of my old rebirth lines. if they sound correctly...and they do...
so it's time now to include the memory for the patterns...at the moment i use the cpu memory...that's of course not enough...
|| i continued today the online editor...included the up and down feature and coded a small reader for rebirth songs...some time ago i converted some of my old rebirth lines to the tb 303 and recognised it sounds quite the same on the original...i mean from sequencer side...so i checked if my rebirth songs are sounding the same...but they don't...there seems to be a slight difference somewhere...but i didn't checked it until now...well that rebirth thing is a bit easier to test with...i mean i always need to plug in the old cpu...would be much easier to have a second 303...hm if it replays the rebirth songs correctly i will do some 100% tests...like replaying the same pattern with new firmware and with the old firmware and comparing the signals via the logic analyzer...
|| the logic analyzer works fine so far...and i started to analyse the internal signals... first pic a slide from one note to another...
first is the tempoclock...means 6 clocks are 1/16 note...
second the gate signal
third slide and dac strobe...
as you can see the gate is on the entire time...(of course) but slide is only hi on the second note...which means the 303 slide always starts on the second note...not on the first ! i recognised there is a small latency between the clock and the gate signal...on latency is round about 1.8-2.2 ms...off latency is 2.8-3.5 ms but that values are jumping a bit...dunno if this is the analyzer or the acid ghost ;)) so the devil fish's description is not 100% correct...the note off is on 3 and not on 3.5 with a small delay of 2.8-3.5 ms which is always fixed independent from the tempo...that's more logical...i mean to get a 3.5 timing is a bit hard to realize with a 6 clock...anyway next one is a simple patten which just replays two note without slide:
very good to see the dac data strobe...accent logging is not working at the moment hm dunno why... but to behonest the analysation didn't show something new... maybe i need to check patterns which are more complex... beside this i found out why the sequencer had a small bug...the accent signal has to be set before the dac strobe...because the dac strobe is also the strobe for the accent latch...otherwise the accent is shifted to the next note...uhh...
|| continued the online editor a bit today...but no big steps...anyway the sequencer still has a bug...hm and i really need to check the excat timing of gate slide accent and bla tomorrow i will do a small logic analyzer via the printer port...so maybe i can figure out what's the acid ghost in the 303's sequencer then...next will be a midi out... at the moment only midi in is included...but no big deal...
|| i could fix the sequnencer problem today...and uploaded the first sequence done with the new 303 firmware...;)
really the first without checking the real original behavior of the 303...i just coded how i gruess the 303 could work...so do not plain ;) later i will check it agains a logic analyzer...
the sequence is a bit hm well not the best one i know...it's done with a hex editor...;)
get it here: ->firstNoises.mp3 (850 kb)
beside this... i did today the midi interface hardware and coded a minimal implementation for note on and off...works ...nice and
wow ! i coded a small editor on pc and now i'm able to edit the internal sequences on a pc via midi great!
click to watch to it:
of course it's not 100% finished yet...but i can edit the notes already...slide accent and stuff is not working at the moment but i'll include it tomorrow...should be enough for today...it was a really productive day...!
|| i connected the lcd again today to the new pcb and i had to recode some stuff to get it to work...but works again... that's nice...now i can see what i'm doing ;) hm somehow the sequenzer has a bug...dunno have to do some investigations later...a bit stressy to compare the sequences with the original firmware...i always need to plug in the old cpu...hm...anyway i have now 4 days mini vacation... so i hope i can manage that sequencer problem soon...
|| service routines to drive the leds are finished now...beside this i did some source cleanup...next will be the service routines for the switches....
|| i started to implement the switch board...leds are running now... cool...switches from the panel are working now too...fine...but all big problems are now solved from hardware side...i thought the tempo knob is much harder to realize...anyway... next todo is:
1)some service routines for a better handling of the switches and leds
2)midi interface...that is no big problem...i already did it once for a another project...and even service routines are finished...
|| couldn't sleep because if the tempo knob...and after some minutes of work and choosing a different way how to get the tempo...it works ...niceness ;)
|| bla...wasted nearly the entire weekend with a silly bug in the hardware...but finally the i found the bug...now i have enough in/outports to control the 303 fully... i coded today the sequenzer and well works fine so far... next will be the note table at the moment the sequenzer just plays the original dac values...i will upload in the next days the first lines...but before i have to create a good sounding line at the moment i have to create the lines with hex numbers in the source ;)
hm tempo knob is working...but not very accurate...hm i have to change this tomorrow...
|| did today a new pcb for cpu and added a bussystem to get more in/outports...to control all features of the 303...i think the in/out ports should run today...so i can start with the main development...
good news and bad news from the 303 project ...
first the bad... i gave up with the memory emulation somehow it don't work dunno why...i never got the "write" to work... anyway...that's life...
now the good news... but i desoldered the cpu today and replaced it with my own cpu...and well what should i say...i'm just hearing my very first pattern created with my own sequenzer... ok isn't a real pattern more or less a pattern created with counter and bla...but i didn't expected that it works after a few hours of work.. even accent and slide is working fine ...;)
but hell that is cool ;)
|| reading from memory seems to work now...but somehow writing does not work...hm wr is never on low...hmmhmm...anyway i've got today the 32kb memory chips now i can replace old the memory...before i had to use some of the old tb 303 memchips ...but to include the new memory some extra soldering is needed...bahhh i have that....
|| back to the tb 303 memory emulation...hm yesterday i finally had success...the tb 303 now reacts on stuff i send to the datalines...after searching nearly the entire night why it doesn't work... i found out it was just the signal level... the 303 cpu didn't recognised my data i sent to the datalines as hi...unfortunately it was too late to do some more tests...at the moment i just send a values which are incremented every chipselect to the datalines but the 303 reacts...that is cool! seems the internal memory format is very easy...
but i think this was the main problem... seems the cpu is fast enought to emulate the memory...i could figured out the chip select from the memory is round about 90 nop on low (means 90 nops counted with my 24 mhz cpu) so fast enought.. so next will be to reactivate the memory emulation again... i hope a write to memory will also work... but we will see... shit i have to work today...i want to go home to check the memory writing ;))
|| some days ago i had an idea for my tb 303... well one thing with a real tb303 is really annoying ...it always needs power not to forget the patterns...and you can't backup the stuff...303 editing is stressy... when you ever used the editor of the 303 you know what i'm talking about...;)
of course you can use midi...i added midi some time ago to my 303 but to be honest it isn't very impressive with midi...the originality of the 303 is gone without the internal sequenzer...
so my idea is just to replace the ram of the tb303 by a cpu (89c51rc)...so the cpu would emulate the ram of the tb303 and beside this it could be used to edit and backup the ram via midi... means i could do a editor of the 303 patterns on pc...the 303 is playing a pattern and i could edit it during it plays...sounds like a dream ;) so far i know the tb 303 chip is running with 455 khz...my cpu is running with 24mhz! so must be really fast enought to emulate the ram i think...
so i was very brave and desoldered the ram-chips of the tb 303 ;)...and connected it to the cpu... and well works a bit...but dunno somewhere is a bug in the software or connection...but bla at saturday i blow up my last 89c51rc... so i have to wait until the new arrives...
of course a new project...hm and i didn't wanted to start a new one...but this one i couldn't resist ;)
hm the best way would be a full cpu replacement...means desoldering the old cpu and replace it with my cpu...but that means the entire software had to be rewritten...i studied the schematics a bit in the last time esp. the implementation of the cpu and the ports and ram that should be possible... but that would open up impressive possibilities... the syncing could be done via time code for example...that means never syncing problems again...or vibrato to the vco ...midi implementation backup of the patterns maybe a editor on pc and a lcd display...but hm anyway mega interresting project but maybe some day i will do this...first the ram replacement should be enough...
hm but i didn't blow up the 303!...it's still working but doesn't but doesn't look like a 303 at the moment ;) that's great