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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Bin file itself as this is what i use to burn the Eproms but will wait to see eporm you think this will work the way it should before i attempt to complete the file. The Channel Change module runs on 12V DC fed from the rack supply and if i can use this to power the Logic probe would this give me the ground signal for the probe to check the status 27c4 the lines?
You can always tell a programmer by the way they count on their fingers then take their shoes off to eprrom on their toes as well! Last edited by tait ; 21st April at 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. Usually in this scenario, the bits are used to set the division ratio in a PLL controlled oscillator and hence the frequency it is tuned to.
Turn on power triac – proposed circuit analysis 0. 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.
Programming File for 27C64 Eprom Sorry for the late reply – I’ve had a minor accident and can’t sit upright at the moment! If that isn’t physically possible to do, with the power off, measure the resistance between the GND pin and nearby chassis to make sure they really are connected then use the chassis as the negative connection point.
This means only of the possible EPROM addresses are actually used and although not marked on the schematic, address lines A8 upward are all unused and tied to ground.
Bits 7, 6, 5 and 4 make the first character and bits 3, 2, 1 and 0 make the second character.
In other words anything higher than 2. How can the power consumption for computing be reduced for energy harvesting? What I meant by using a small micro was you can achieve the same result as using a ‘hardware’ EPROM look-up table by doing it in software. Remember it doesn’t hold a program, it’s just a look-up table so it wouldn’t use more addresses than there were things to look up. Dec 24 fprom, 8: I have the circuit below of the Channel Change module that describes how the 27c4 of the Two Pushbutton switches are latched and then feed the 27C64 inputs but i am unsure what input location to start from, I.
Apologies for the long first post but if anyone could point me the right direction as to how to create this file i would be most grateful before i wear out my UV Eraser or the Spare Eproms i have been using to test the files Regards.
27C64 – 27C64 64K EPROM Datasheet
Thanks again for your help, Regards. I will try 27c664 scan a copy of the Circuit Diagram from a hard copy i have.
For example if the input lines were the address is C and you wanted to output on the data lines the value to place in C would be 9B. Thanks again for your time, Regards, Chris S. Whether the output bits are correct or not depends on what they do later on in the radio. Thanks again for your help, Tait I am not fluent with Eprom programming and i have probably messed up the conversion from Binary to hex or placed it in the wrong location.
Thanks for your Help, Brian.
Last edited by tait ; 22nd April at This is exactly what is required, the Thumbwheel switches generate the line states from a Numerical setting 01,02,- 99, etc and the module displays these on the 7 seg Leds and switches epdom output lines to match, controlling the Radio Modules. The radio module Eprom is working correctly as i can manually select the Channels via the 8 pin Dip switch and they follow the Dip Switch codes eprpm the manual.
It that is the case, and if the radio is working at the moment, I suggest you note the voltages on the EPROM outputs for each channel number you select. If 27d64 is true would i be able to measure with a DVM on DC volts the output state of the data lines out of the Channel Change eprom to confirm i have the correct lines either epromm or low to replicate the Dip switch settings on the Radio Eprom Board?
Choosing IC with EN signal 2. The device is a Remote Channel Change module for a Repeater rack and allows remote selection of channels in the TX and Rx modules by pulling various data lines in the same chip installed in the modules either high or low depending on the channel selected.
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.
BTW – my back is much better thanks.
27C64 Datasheet pdf – 64K (8K x 8) CMOS EPROM – Microchip
Programming File for 27C64 Eprom Hello, Was wondering if someone that has had some experience in creating a BIN or HEX file suitable for a 27C64 Eprom could point me in the right direction re creating a file that would allow the above Eprom to control the output of its data lines D0 – D7 so that it will switch the lines either high or Low i.
If i wanted to select 01 on the Pushbutton switches how would that relate to the input states of the Eprom data lines? KRF4A 27c64 clone programming. The problem is knowing where to stop, not where to start!
There will be gaps in the contents of the EPROM so don’t worry if there are empty addresses you don’t use. It is very easy to convert the bit pattern from binary to hexadecimal.
You could replace the whole module with just a 72c64 of modern components, in fact you could replace the entire selector AND channel EPROM board with a simple micro and a display driver circuit.
Bin files i have seen before. ModelSim – How to force a struct type written in SystemVerilog?
It makes reading and writing a bit difficult. Measuring air gap of a magnetic 27c6 for home-wound inductors and flyback transformer 7. Programming File for 27C64 Eprom. 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.
I’ll respond as soon as I can. Measure the voltages on all the Address lines and write down whether they are high or low epgom a binary number, for example: Because of the strange way the EPROM address pins are connected, the input digits are reversed so if you want channel 10 you use address 01 instead.
Programming File for 27C64 Eprom Hello Brian, Hope you are feeling a bit better, Would you mind having a quick look at the attached Circuit diagram of the other end of this Combination and tell me if i can do a check of which Data output lines coming out of the Channel change module are either “High” or “Low” depending on which Channel is selected?
What is the function of TR1 in this circuit 3.