The Microchip Technology Inc. 27C64 is a CMOS 64K bit (electrically) Programmable Read Only Memory. The device is organized as 8K words. 27C64 64k (8k X 8) CMOS EPROM FEATURES. High speed performance ns access time available CMOS Technology for low power consumption 20 mA. 27C64 EPROM Datasheet, 27C64 64K EPROM Datasheet, buy 27C
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EPROM MEMORY 27C64 DIP
PV charger battery perom 4. Whether the output bits are correct or not depends on what they do later on in the radio. The on the third schematic is periodicaly pulsing the latch signal so the switches are read in. Dec 248: I would guess the data ends up in a PLL circuit elsewhere in the radio so the equal sized jumps in EPROM data would suggest that the same frequency spacing exists between each channel 10Khz, 25KHz or whatever. What we do is split the 8 bits into two 4 bit characters.
It makes reading and writing a bit difficult. I have printed out your reply and will study it tonight in detail when i can concentrate on it fully. Bin files i have seen before. Logic probes are usually designed to respond to very short pulses that a DVM would probably miss but in your radio the signals are DC anyway so they should give the same result.
Measure the voltages on all the Address lines and write down whether they are high or low as a binary number, for example: Bin file itself as this is what i use to burn the Eproms but will wait to see if you think this will work the way it should before i attempt to complete the file. What is the function of TR1 in this circuit 3.
You have cleared up a lot of my confusion over this and have given me a Good place to start, time to do some serious study. Will be in eprm when i have had a good look with my thinking cap on. Synthesized tuning, Part 2: Last edited by tait ; 21st April at The “External Interface” on the left Sprom top is where the Channel Change eprom output connects to directly and you can manually select any of the channels that have been previously programmed via the Tait Software into the radio’s own Eprom, via the 8 DIP switches.
It’s better to share your questions and answers on Edaboard so we can all benefit from each others experiences.
What you ask for is very easy to do, you need to think in hexadecimal though instead of decimal. Thanks again for your time, Regards, Chris S. The CD can only decode decimal numbers so I’m guessing the range you can select is from 00 to 99 and is BCD coded.
Equating complex number interms of the other 6. Programming File for 27C64 Eprom It’s a strange system, if if the date is difficult to read it was well into the era of microprocessors so using so much discrete logic seems a bit backwards.
I worded that badly, not sure now what info i need so fprom the Eprom can decide which output lines to pull low Ground Apologies. I would be very grateful for any further assistance you might be able to provide on the above.
27C64 – 27C64 64K EPROM Datasheet
Input port and input output port declaration in top module 2. Then for each input state, write the output state you need, this is what the EPROM should produce on it’s data lines. I have a circuit Diagram of the unit and the input to the Eprom is already there with the BCD switching done by a pair of chips.
Programming File for 27C64 Eprom 27cc64 them thanks.
27C64 Datasheet pdf – 64K (8K x 8) CMOS EPROM – Microchip
The problem is knowing where to stop, not where to start! I wouldn’t be too concerned about what other people find amusing, seeking Humour in other peoples misfortune normally indicates a low self image problem.
You might be able to use binary but it’s horribly tedious. The trouble is it has a fluorescent display and few modern processors can drive it directly. Thanks again for your help, Tait