Archived posting to the Leica Users Group, 2001/01/30
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Sure sounds like a Mitsubishi 7702. Very common, very cheap low-power processor for embedded applications. You find them doing things like controlling not-very-new cordless phones or VCRs. Now, if all you guys who have all this time to brag about writing machine code really want to show up the likes of Tom A in terms of camera customization, you should pop out your R8's 7702, read the ROM, and disassemble the code. You could, for example, find the differences in the code between the early and later R8's. What's more, there's a special development version of the 7702 (probably costs $2 instead of $0.15 or whatever) that has a one-time PROM instead of the ROM! So you can write new control code, hack around hardware deficiencies in the early R8's, do fun new things with the motor drive, etc. Maybe you could customize the bracketing or add new metering modes. There's only the small matter of unsoldering and resoldering 80 very tiny pins... Personally, I only use mechanical cameras. The very idea of using a camera that is running 13,000 lines of code makes me want to go out and buy another SL MOT. Come to think of it... No! Get thee behind me, Ebay! - -Patrick > From: Dennis Painter <dpainter@Bigfoot.com> > > Interesting, most especially the 80 pins, sounds like the cpu is not > embedded in an ASIC. Volumn considerations I would guess. > > Anyone have a schematic? ;) > > Pascal wrote: > > > > On 23-01-2001 15:45, Dennis Painter wrote: > > > > >Which CPU(s)? ;) and to be OT, anyone know what CPU is in the R8? > > > > The CPU is based upon a 16 bit Mitsubishi chip with 2K RAM and 60K ROM > > running at a clock frequency of 8 Mhz. The CPU is 80 pins, it has 8 > > timers, 2 UARTs, an 8 channel 10 bit ADC and a 2 channel 8 bit ADC. All > > data exchange with the camera's internal electronics are done via a > > serial interface. Power supply is 3.8 volts. > > > > The software to run the R8 requires more than 50K ROM. > > > > (source: J. Eastland's Leica R8 book) > > > > Pascal > NO ARCHIVE >