On Tue, Jul 1, 2014 at 8:33 PM, Mike van Bokhoven <mike at fenz.net> wrote: The 68x09 (no E suffix) has an internal crystal oscillator circuit (pins 38 and 39) and generates the required quadrature clock (E and Q, pins 34 and 35). The 68x09E requires an external quadrature clock input (E and Q, pins 34 and 35), and uses pins 38 and 39 for other functions (LIC and TSC, respectively). Generally speaking, no.

On Jul 1, 2014, at 22:33, Mike van Bokhoven <mike at fenz.net> wrote: I believe it's a matter of whether the two-phase clock is generated internally or externally. The E requires it to be externally generated, and that's what I'm familiar with; unlike the 6502, it expects a 90 degree phase shift instead of 180 degrees. I don't think they're easily interchangeable; besides the fact that the E and Q pins are outputs on the non-E version, the LIC and TSC lines are taken up by the crystal oscillator pins and the DMA pin behaves differently (not all of this will matter in a pinball controller board, but at the very least you'll need to make an adaptor board. My advice, faced with a dwindling supply of pulls (you used to be able to buy 'em by the bushel from Jameco) is to consider making a drop-in replacement using one of the many VHDL/Verilog models now available and a cheap, tiny FPGA like the MAX II (which Altera likes to call a CPLD, even though it really isn't) mounted on a DIP carrier board. I wonder if there's a market in that for the arcade community... - Dave

This is becoming real problem. The remarked devices, of course, have no relation to what they claim to be, they can't possibly work. Heck, I once enqired about a replacement for an HP custom IC and was asked 'what package, and how many pins'. Given this device had only ever existed in one pacakge, with one particualr pin count, it wa obvious I was goign to get a fake. I do wonder why they botyher. They can't make that much money selling to hobyists, surely no commercial company wants such fakes. he difference is where hte clock circuitry is. The 6809 (normal and E_) need a pair of clocks in hase quadrature. The E clock (Enable) and the Q clock (Quadrature). FWIW, the 'clock rate' of the 6809 is specified as the frequency of these clocks The 6809 (on E) has an internal clock generator. It can be driven by a crystal of 4 tiems the CPU clock rate (soe a 68B09 can use an 8 MHz crystal). The E and Q pins o nthe chip are outputs The 6809E (E=External) has no internal clock generator. The E and Q pins are inputs, to be driven by an extgernal circuit that produces the approrpatie signals in phase quadrature. IIRC, i f you use the 6883 SAM (DRAM controller) you prettty much hace to use the 6809E. The SAM generates E and Q, and expsects to eb able to synchroinse the CPU to them. That depends on the circuitry around the CPU. However, if it sues the 6809E CPU, it's a fair bet it is goign to do oomething odd with E or Q (perhaps stretchign one of them when acessing slower memory or something). In which case, tryign to use the plain 6809 is goignt to be a lot of owrk. The 6809E was origianlyl chosen for a reason, after all (and I doubt it was cost, the cost of the external clock curcuit would outweight any difference in price of the 2 chips when new), so the reason is more likey that said clock circuit does soemthing extra that can't easily be done wit hthe plain 6809. -tony