Hi Hamish,



On 22 Jun 96  16:00:00, Hamish Moffatt wrote to Tom Przeor:



I've received your message just today - look at your date??



 HM> Thursday June 20 1996 09:10, Tom Przeor wrote to Hamish Moffatt:

 

 HM>> Maybe it's a [P]ROM, ie not erasable. 27 series is generally normal

 HM>> [EP]ROMs, while 28 series are EEPROMs, which are electrically

 HM>> erasable, hence "flashable."

 

 > Quite possible...but all 27 series I've dealt with were UV erasable

 > but this chip doesn't have a window. I'm lost now.



 HM> Someone said it was an OTP ("one time programmable"), which sounds

 HM> just like a PROM to me.



No difference from our point of view but PROM is programmed during

production and anyone with EPROM programmer can program an EPROM.

OTP saves money with cheap plastic package instead of ceramic with

quartz window. Once programmed they cannot be erased. That of course

doesn't mean they cannot be reprogrammed - as long as you want to

change "1" into "0" it can be done by programming again.



Cheers,

Tom             



--- Blue Wave/DOS v2.30 [NR]