Syntor X - 2716 EPROMS?

[maxkelley_kc2spy]

Hi all,

I have a Syntor X VHF with a orange-label memory module, which has a Xicor X2816A EEPROM in it currently. With this EEPROM, it functions just fine!
I've tried numerous times now to program 2716 EEPROMS (even copying the same info from the 2816 to a 2716) and it doesn't seem to be working! Can you put 2716 uv-erasable EPROMS into the orange-label memory module? When I put a 2716 into the module and load it into the radio, the VCO unlock LED turns on and I hear the antenna relay clicking constantly.

Any insight? Anybody still know how to program one of these?

[Jim202]

Hi all,

I have a Syntor X VHF with a orange-label memory module, which has a Xicor X2816A EEPROM in it currently. With this EEPROM, it functions just fine!
I've tried numerous times now to program 2716 EEPROMS (even copying the same info from the 2816 to a 2716) and it doesn't seem to be working! Can you put 2716 uv-erasable EPROMS into the orange-label memory module? When I put a 2716 into the module and load it into the radio, the VCO unlock LED turns on and I hear the antenna relay clicking constantly.

Any insight? Anybody still know how to program one of these?

The 2716 and the 2816 are not the same animal. Go to Digi Key and get the right chip if you think you need them.

Jim

[Andy Brinkley]

Ditto what Jim says, why don't you just reprogram the 2816 eeprom?

A 2716 eprom can be made to work but you have to modify the memory module.

[maxkelley_kc2spy]

A 2816 is a EEPROM, a 2716 is an EPROM. I only have a EPROM burner, it won't do EEPROMs. I had heard of people using 2716s with success, so I figured I'd try and make do with what I had! I compared the pinouts of the two, and as far as data lines go, they're identical, the only difference being a few things related to the electrical erasability of the 2816.

[Andy Brinkley]

The I/O pins are the same but take a close look at pin 21. This pin function is not the same. There may be more that aren't but this one sticks out in my mind.

You will need to verify but if my memory is correct in the Syntor X memory module Pin 21 is tied to Vcc for the 2816.

In order to make a 2716 work you need to remove Vcc from this pin and pull it to ground.

[maxkelley_kc2spy]

The I/O pins are the same but take a close look at pin 21. This pin function is not the same. There may be more that aren't but this one sticks out in my mind.

You will need to verify but if my memory is correct in the Syntor X memory module Pin 21 is tied to Vcc for the 2816.

In order to make a 2716 work you need to remove Vcc from this pin and pull it to ground.

OK, just to test this, I bent the pin 21 on the EPROM out so it doesn't go into the socket, and attached a ground lead to the pin which I attached to the chassis. Still no difference.

Anything else you can remember about this?

[Andy Brinkley]

Sounds like your data may be flaky (wrong bandsplit, bad vco select bits, etc) or does not match the control head / radio configuration.

Send me your data and I will look at it.

[Astro Spectra]

First check the data in the two memory parts are the same.

If you're careful you can put the X2816A in your EPROM burner and read it, but you'll need to manually set the programmer to normal 2716 mode and whatever you do don't allow the burner to try and program the X2816A in 2716 mode otherwise it will be instantly destroyed. Do not set the programmer to Texas Instruments (TI) or CMOS 27C16 types. After reading the EEPROM data in pop in your 2716 EPROM and do a compare.

Next up check the exact type of 2716 you're using. There were some real flaky types in the early days, like CMOS parts that need Vcc above 5 volts or the TI parts that were just different. So avoid CMOS and TI style 2716 devices.

Pin 21 on the X2816A is /WE and must be at TTL logic high, 2.4 volts or above, to read.

Pin 21 on the 2716 is Vpp and must be at Vcc (+5V) to read. So check that there is +5 on this pin when inserted in the radio. You may find it's at logic high rather than at Vcc which is not good enough, in that case then use your 'bend the pin out' trick and jumper it to pin 24. Most 2716 types draw current during operation from Vpp.

[maxkelley_kc2spy]

Excellent! It worked perfectly! Thank you so much Astro Spectra, and Andy as well! I jumpered it to pin 24 and it worked.