Trilobit
209 posts

Trilobit
@relo999
Game designer, artist, modder, retrogamer, tabletop gamer. Why pay when you can build it?
Holland Katılım Temmuz 2010
190 Takip Edilen37 Takipçiler

@cyothevile I tried getting the full pinout of the CD interface connector on my Fresh, but no luck as they all go to some IC for which I can't find a datasheet (or a 74hc244 and then go to those IC's).
English

@cyothevile Might be useful information (specific to the FMT Fresh), the only other drive that uses the same drive mechanism uses a panasonic interface so the Fresh might just use a pinswapped Panasonic interface. The panasonic interface has been implemented in PiPico (PicoGus uses it).
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FM Towns CDROM drive mechanism recieves an 8 bit wide command/opcode from towns host to a custom fujitsu microcontroller on disc drive pcb. On Marty I think its two 4 bit MCU but on a computer it comes from bus master ASIC powered by 8086 core.
Drive MCU doesnt expose an interface to readout the flash ROM. Frustrating. Would be helpful to disassemble the opcodes and follow on command frame.
Fujitsu microcontroller RX opcode bytes and subsequent commands and sends configuration to cd drive LSI to begin reading the data output. This include cdda on tracks 2 to 99, data track 1 and sub registers. Im not sure if this is a bidirectional interface.
Disc drive has Q register out and I believe other subs are on another strobe bus with similar 75hz frame. There are two 75hz strobes which makes me suspect that sub P and Q are together on one bus, and R to W are on another.
Standard 44.1khz i2s that goes into an ASIC to perform audio mixing/dsp task. Also ty furrtekk for infinity patience when confirm drives usually go to 1x speed for cdda mode.
Cd data for track1 is sent by a serial interface with a frame I don't quite understand yet. But just two wires. Theoretically a faster clock with data rate can net a 4x drive etc. Depends if towns host accept it or not.
I now understand why Deunan for example recommended CCD format; less resource intense for MCU to just run pointer down SUB file as its aligned to data/cdda pointer. But then again regenerating sub Q and possible P should only take a few bytes and cycles to prefetch and align with other circular buffers.
I should have more equipment arrive on the weekend to really dig into the subcode interface and serial data frame. Thing to remember is town like all drives immediately looks at LBA0 to find an OS to boot. Something to keep in mind for when parsing bits on logic analyzer.
English

ゲームポケコン マルチカートは自分で組み立てられます。販売用のカートもいくつかありますが、オランダからの発送になります。もしかしたら、自作できるかもしれません。tinnedtrace.wordpress.com/2025/05/01/pok…
日本語

@relo999 自分は自作カートリッジのRAMとかの/OEには本体側のコネクタの/RDをいれてました
こちらのEnriさんのサイトを参考にしていたと思います
cmpslv3.stars.ne.jp/Scv/EnrScv.htm
日本語

@political @elonmusk It's hard to measure things accurately you don't have the ability to measure properly. Even assuming you're right, security perception is important. Both sides claim fraud and the election was illegitimate when they lose. Voter ID makes those claims harder to substantiate.
English

@RyuKaiser29 @CHSommers @SethAMandel It's an important note of the original and kinda lost when Disney touched the story but the point is that the queen was extremely vain and beautiful. It's not that she's ugly, it's that she doesn't want other women to be perceived as being possibly more beautiful than her.
English

@relo999 Dat is vervelend! Bij iDEAL is momenteel inderdaad een technische uitdaging aan de gang, maar PayPal zou wel moeten werken! Mocht dat nog niet zo zijn, dan ontvang ik graag een DM. Dan kijk ik met je mee! ^Davey
Nederlands

@thuisbezorgd Zowel de storing op Ideal en Paypal? Beide lukken niet.
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