GE Series One CPU 106B ROM

Ok so I've got this CPU with a TMS27C256-120JL Eprom (I belive it's and EEprom since there's no window. The three jumpers are in the "ROM" position.

I'm presuming that by moving the jumpers to "RAM" I should be able to overwite the existing program on this chip?? Right??

Thanks in advance, Mike

I don't think the Series One ever had a EEPROM option. The only non-volatile memory was EPROM. You had to use their PROM writer unit to copy the program from RAM to the EPROM. The EPROM mentioned in the manual for the Series One Plus was the 27256-25, which is similar to what you've got.

The jumper settings for an EPROM are A to B and D to E, and SW2 should be in the OFF position.

The CPU106 was the model with 3.7K memory, but I can't remember if all the memory was on a single chip. It's possible that the chip is additional RAM. The same socket was used for either EPROM or additional RAM in CPU101, CPU104 and CPU105 models.

Edit:
Sorry, I didn't clearly answer your question. If that chip is an EPROM, the only way to write to it is by using the PROM writer unit, part number IC610PER154.

Thanks for the reply Steve,

This is'nt my program, but the customer was looking to make a minor change. I'll have to look in the war chest for a prom writer..(it's been a long time).

Later..

I just checked my AD catalog. The CPU106 is almost the same as the D3-330. The catalog says that EEPROM is not an option for the D3-330.

It looks like your options are to locate the PROM writer or replace the CPU106 with D3-340 equipped with EEPROM. That would also involve converting the program from Logicmaster to DirectSoft since Logicmaster does not have any utility to store a program to EEPROM.

Steve Bailey said: That would also involve converting the program from Logicmaster to DirectSoft since Logicmaster does not have any utility to store a program to EEPROM.

Click to expand...

The good thing here is it should be a direct import into Directsoft.

The only things you have to be sure of when converting to a D3-340 are:

1) You cannot have a comparitive contact as the first item off of the power rail in a CNT or TMR rung.

2) MCR or MCS coils cannot 'OR' with another coil

Thanks for the tips guys,

If the program is compatable, and the customer want to pay for the time and CPU, then I'll go the 340 route.

Have a good one...

Mike.