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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I am not sure what the other logic does on this pin as I only located a partial schematic. Anyone know why eproj would be? I checked the Cromemco Bytesaver schematics and there is a pull-down resistor on this pin. Dave, Thanks for the info, my current adapter is working.

Poi si deve collegare il pin Not Chip Select 20 ed il pin di programmazione 18 a massa. Professional tools that can do this task are really expensive.

Perhaps there are some which ignore this pin – or it is a “no connect” pin. I would suspect, therefore, that pin 18 is connected to ground by default logical ‘0’ when it is read mode.

We need to wait the correct 7208 for the data to be burned about 1 ms according to the datasheet and put back to ground the programming pin Please write us eprkm any error, missing part or comments!

I still don’t get how you expect one adapter to suit s and s?

Where would I connect these three pins on the or ? Every byte is separated by a space character. Bookmarks Bookmarks Digg del.

File EPROM installed in Cromemco – Wikimedia Commons

Forum Genres S eprom substitution, Isn’t that what the adapter plugs into? Q7 il dato letto.


I have a 2k monitor program in the top 1k of two ‘s, in two sockets each with an adapter, and the program runs as 2k of continuous memory. 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. As I said I will try Dave’s suggested wiring and post results I expect it will work better. I’m still not getting this: I appreciate the input and don’t get me wrong I accept what you guys are saying.

I’ve got an 8k Bytesaver card in my machine which I’ve loaded up with the 8k Basic bootloader. 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.

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 also loaded the Altair Rom written by John Garza which enables deposit and examine of memory from a terminal, as eprmo as the 4k Basic loader and a few other great features. 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 dprom.

We’ll assume you’re ok with this, but you can opt-out if you wish.

File:2708 EPROM installed in Cromemco Bytesaver.jpg

In my reasearch I’ve read that ‘s are pin compatible with ‘s so I figured I could use the same adapter with ‘s. This should, therefore, mean that you would need to program the “low half” of the ? The other confusing thing is that you say you program the “high half” epprom the – but pin 19 A10 is linked to ground. Epron Posted by daver2. Results 1 to 10 of Pinout is the same but the address bus, that is 9 bit instead of Either way – you may find some manufacturer’s devices may not work i.


I have to agree with everything Dave says. Facebook Twitter Google Email Print. So, the pin 22that in the is the 9th address line, in the is a ground. Page 1 of 3 1 2 3 Last Jump to page: Monday September 10th, Tuesday August 5th, admin. So it seems the adapter as I originally wired it only works for ‘s. PCB board layout and circuit schematics. The data bus is 8 bit, so we can directly connect the bus data to one port of the PIC.

2708 / 2704 EPROM reader / programmer

Originally Posted by MikeS. Pin 21 of the is Vpp which should be wired to pin 24 Vcc for normal operation. I can program the ‘s using the Top, that works fine, but when I use them in the Epom, the Altair doesn’t read them.

Originally Posted by kingchops. Moreover, we need a way to transmit data to a PC, so we need other two pin for a serial port.

I tried reading a in the adapter and that didn’t work.