[sdiy] Cheetah MS800 WAVE ROM craziness!

MTG grant at musictechnologiesgroup.com
Mon Jun 7 20:14:45 CEST 2021


Some of that stuff (the file path for instance), might just be in the 
memory block where the sample data was loaded. For instance if you start 
up an EPROM Programmer's software, it may not initialize the image 
buffer area. Normally you'd want that initialized to all 0xFF, but not 
all programmers do this by default. So you might be seeing, among other 
things, raw memory on the original user's machine. I've seen this happen 
before. May or may not be true in this case.

GB

On 6/7/2021 10:42 AM, Richie Burnett wrote:
> For those interested in a bit of vintage equipment "hacking" I've read 
> both EPROMS from the Cheetah MS800 to raw binary files.  The 8Kbyte PROG 
> one has 6502 machine code in it.  The 32Kbyte WAVE EPROM is very strange 
> though...
> 
> When loaded into Goldwave as 8-bit signed data the first part of it 
> contains the MS800 wavetable waveform data in delta encoded format.  
> This delta encoding is mentioned in the M114S datasheet, (the chip that 
> plays back the wave tables.)
> 
> Then there are some low-resolution *DRUM SAMPLES*, (cowbell, kick & 
> snare!) also delta encoded.  For example, the snare drum sample sounds 
> very TR-909 like when integrated and played back at 8kHz sample-rate!
> 
> I can't recall ever hearing my MS800 produce any drum sounds, but I 
> guess someone on the design team thought it was a good idea to put them 
> in there for some future or un-documented purpose.
> 
> The samples are then followed by a load of weird ASCII text in the 
> second half of the 32Kbyte address space.  Very strange considering the 
> MS800 only has a 2-digit 7-segment LED display!  Some of the ASCII text 
> follows...
> 
> 
>    »O 3%1b00   6912  ine45w.del  ('sin45w')
> $000d00   3328  rsine.del  ('rsine')
> $000e00   3584  amsine.del  ('amsine')
> $000f00   3840  amsine5w.del  ('amsine5w')
> $001000   4096  squ20.del  ('squ20')
> $001100   4352  noise.del  ('noise')
> $001200   4608  ntri.del  ('ntri')
> $001300   4864  chirp4.del  ('chirp4')
> $001400   5120  chirp16.del  ('chirp16')
> $001500   5376  part1w.del  ('part1w')
> $001600   5632  part4w.del  ('part4w')
> $001700   5888l    LVªJ–Oppó#Jª01¤O. LV 
> ª®O¦ª\Q
> ¸OتüRrQrQªÿÿüR2ÿ
> 
> ºQp JT    »QfQQ p Š    p  ‰     ‰ QQY
  Š 
> Šÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿl 
>   NXºZ6Qÿ   Π          >       @  `@ ²RfQppÀ%µ  F
> ~Q9 @ ` `@ `2üR  `òRR@   `²ÿÿ         €  º  snared   
> ÿÿÿÿÿÿÿÿÿÿÿ '   nare.del 
> ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ€ª€. 
> ²  Y üR6TSS S,S  C:\C\BIN\MAT2BIN.EXE -k24 chwave5.lst 
> chwave5.rom pø 
> COMSÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ 
> part3.del  ('part3')
> $001d00   7424  part4.del  ('part4')
> $001f00   7936  part5.del  ('part5x')
> $002100   8448  part6.del  ('part6x')
> $002300   8960  bass.del  ('bassd')
> $002700   9984  snare.del  ('snared')
> $002e80  11904  << end of last file loaded >>
> 
> End of list file found
>   chirp4.del  ('chirp4')
> $001400   5120  chirp16.del  ('chirp16')
> $001500   5376  part1w.del  ('part1w')
> $001600   5632  part4w.del  ('part4w')
> $001700   5888  part1.del  ('part1')
> $001900   6400  part2.del  ('part2')
> $001b00   6912   sine.del
> sine12w.del
> saw.del
> tri.del
> squ50.del
> delta.del
> sine15w.del
> sine17w.del
> sine125w.del
> sin1379w.del
> sine179w.del
> sine29w.del
> sine45w.del
> rsine.del
> amsine.del
> amsine5w.del
> squ20.del
> noise.del
> ntri.del
> chirp4.del
> chirp16.del
> part1w.del
> part4w.del
> part1.del
> part2.del
> part3.del
> part4.del
> part5.del
> part6.del
> bass.del
> snare.del
> art6.del
> bass.del
> snare.del
> 
> etc...
> 
> 


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