The restoration of computers like our SAGA FOX LS, containing an EPROM , gave us the necessity of reading, and so storing, the. , , , , , , 27C, , 27C, , 27C, 27C, , , EPROM series. EPROM and CMOS. The Bytesaver card only uses eproms, but I’ve managed to create a socket adapter to use ‘s instead. And I’ve used the Top

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eprom substitution, ,

I’m still not getting this: We must simply set the A1 digital port connected to pin 22 of the EPROM to zero, and read only the values between 0 and Monday September 10th, Tuesday August 5th, admin.

PCB board layout and circuit schematics. I still don’t get how you expect one adapter to suit s and s?

Sorry, your blog cannot share posts by email. I did the hack in a socket between the card and chip. I tried reading a in the adapter and that didn’t work. To read a eprom we need 10 output for the address bus, and 8 input for the data bus: I am still a bit confused by your pin Where would I connect these three pins on the or ?

Originally Posted by MikeS. What I also tried was to use eeproms. Pin 19 of both the and is address line A10 so you can wire this to ground pin 12 to use the first half of the device or pin 24 Vcc to use the second half of the device.

In my reasearch I’ve read that ‘s are pin compatible with ‘s so I figured I could use the same adapter with ‘s. I am not sure what the other logic does on this pin as I only located a partial schematic.

As I said I will try Dave’s suggested wiring and post results I expect it will work better. I think the key is pin 21 on thethis pin doesn’t affect reading on thebut the way I have it wired would stop reading on the And I’ve used the Top programmer to program the ‘s on the pc, this works fine. Facebook Twitter Google Email Print. Results 1 to 10 of At this point we have to simply write on the address bus A0…A9 the address of the location to program, in the data bus Q0….


I’ve got an 8k Bytesaver card in my machine which I’ve loaded up with the 8k Basic bootloader. The front panel switches are all still good and working, but I can tell some of the most used switches like examine next and deposit are starting to get a little worn out. Poi si deve collegare il pin Not Chip Select 20 ed il pin di programmazione 18 a massa. Pinout is the same but the address bus, that is 9 bit instead of I would suspect, therefore, that pin 18 is connected to ground by default logical ‘0’ when it is read mode.

Professional tools that can do this task are really expensive. Originally Posted by kingchops. Circuit To read a eprom we need 10 output for the address bus, and 8 input for the data bus: Perhaps there are some which ignore this pin – or it is a “no connect” pin. Whilst you say your adapter works and I am not disputing this the datasheet states that pin 21 VPP should be connected to VCC for correct read operation. So, the pin 22that in the is the 9th address line, in the is a ground.

Forum Genres S eprom substitution, But this didn’t seem to work. The time now is I should also mention that I don’t want to program the ‘s or ‘s when they are in the target system, just read is fine.

2708 / 2704 EPROM reader / programmer

Then I just program the top half of the ‘s and they act as ‘s on the card. Bookmarks Bookmarks Digg del. Page 1 of 3 1 2 3 Last Jump to page: It’s not what we’re saying, it’s what the respective datasheets specify.


Dave, Thanks for the info, my current adapter is working. Originally Posted by daver2. All this means is that your will not enter standby mode i. So it seems the adapter as I originally wired it only works for ‘s. Every byte is separated by a space character.

File:Intel 2708 EPROM.jpg

We need to wait the correct time for the data to be burned about 1 ms according to the datasheet and put back to ground the programming pin Hi, The other confusing thing is that you epprom you program the “high half” of the – but pin 19 A10 is linked to ground.

Data is trasmitted to the serial port as an ASCII sprom, representing the hexadecimal value that has been read. The other confusing thing is that you say you program the “high half” of the – but pin 19 A10 is linked to ground. Either way – you may find some manufacturer’s devices may not work i. I’ll make up and adapter with you suggestion and try it out. I’d put the ZIF socket on the Bytesaver; plug in aepdom the adapter with a in it.

Moreover, we need a way to transmit data to a PC, so we need other two pin for a serial port. I’ve also loaded the Altair Rom written by John Garza which enables deposit and examine of memory from a epeom, as well as the 4k Basic sprom and a few other great features.

Serial port to be used on the PC, speed and connection parameters, the number of readings and the file name to save the dump can be changed editing the header of the Python code.