"David Stinson" <[EMAIL PROTECTED]> made an utterance to the drakelist gang ----------------------------------------------------------------------
----- Original Message ----- From: <[EMAIL PROTECTED]> Subject: Re: [drakelist] U9003 DR-7 PROM Chip- Copy? > I wonder what Drake used. Was it Dos, CP/M, or what? > Also what is the data format? Im curious. No "operating system" per se; the chip works with a Binary Coded Decimal code provided by the bandswitch and DR-7 board itself. As one switches bands or pushes the "up/down" buttons, each 500 KC band segment presents a unique 8-bit word (an "address") to the input of the PROM. Each address is programmed to present a 4-bit word at PROM outputs Y1 to Y4. If you push the "down" button all the way to the bottom edge of a band, the 4-bit word programmed into U9003 sets Y2 output "low," which inhibits the "Up/Down" button- controlled ICs (U9001 and U9002) from stepping the BCD counters that set the frequency range any further in that direction until you change the bandswitch setting. "Up" stepping inhibit works the same way, using the Y1 output. Y3 is tied "HI" and is not used. Y4 goes low (IIRC) when the addressed 4-bit word corresponds to a "legal" ham band, enabling transmit (this goes to the base of a transistor and is the basis of the "cut the transistor leg for all-band TX" mod). For example (and I don't know if this is the right BCD address; I'm just using it for illustration): Let's say you've switched to 40 meters on the band switch. IIRK, you can only step "UP" when you first turn the bandswitch to 40 meters. The band switch will load this 8-bit BCD word into the band-setting counters, U9005 and U9006 respectively: 0100 1011, which equates to "4B" in Hex-code. This is presented to the 8-bit inputs of the PROM. The PROM is programmed so that, when it sees address "4B" on it's input, it presents Hex "A" or 1010 on the 4-bit output: Y1: HIGH - Step "UP" OK. Y2: LOW - Step "DOWN" inhibited. Y3: Not Used, tied "HIGH." Y4: LOW - Transmit OK. Each BCD address that is used by the TR-7's band switching will be programmed in the PROM with one of ten different 4-bit word outputs appropriate to the conditions specific to that 500 kc band. Given all that, we could, if need be, manually work out the programming required. 73 Dave S. ---------------------------------------------------------------------- Submissions: [email protected] Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost: [EMAIL PROTECTED] - help in body of message Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net ----------------------------------------------------------------------
