27c256 | 4K81H | 68HC11A1 | 68HC11P1 | 68hc24 | 68HC711E9 | 68HC811 | 8255 | A2D | ADC | ADC12138 | Am85C30 | BRCLR | Buffalo | CMOS | EEPROM | EPROM | Ethernet | EVB | EVBU | HC11E1 | HC11E9 | HC711E9 | Horray | ImageCraft | IRQ | Keypad | LCD | MC68HC11D0FN | MC68HC11E1CFU3 | MC68HC11F1 | MC68HC711E9 | MC68HC711E9CFN2 | Microcore11 | Microstamp11 | Minikit | NVRAM | PSD | PSD8xx | PSD9xx | PT1000 | RS232 | RTS | RXD | SPI | SRAM | TXD | Watchdogs | XIRQ

Speaking of 27c256... has anyone else had a problem where their 27c256 can't be properly read by the HC11? Maybe this is the issue being discussed here, and I'm just not realizing it.... I have recently had 4 @ 27c256 fail. They program and verify in my needham electronics' programmer, but when I put them into the HC11 circuit, the device goes berzerk. Almost like there's no chip installed at all. The four parts in question used to work just fine. I'm not sure how many program/erase cycles they've been through, but it's certainly nowhere near the lifetime rating. Unfortunately, my four chips decided to die right at crunch time.....Murphy's Law, I guess. Fortunately i had some backups, but now one of those is also acting strange - and this one has been programmed and erased far fewer times than the four that died.... Any light that anyone can shed on this would be greatly appreciated. I'm using a 74-373 to latch the lower eight address bits. I have the three inputs of one gate of a 74-10 tied to AD15, and the output is tied to the chip enable of the 27c256. The R/W pine of the HC11 is tied to the input of one gate of a 74-14, and the output of the 74-14 is tied to the -OE pin of the 27c256. Pretty much "by the book" except for the 74-10 in place of a 74-14 or similar. Thank you, Brian --- ncnghtstkr <> wrote: > 27c256 > > --- In , Michael Bennett <michaelb3443@y...> > wrote: > > exactly what r u trying to program > > > > > > ncnghtstkr <ncnghtstkr@y...> wrote: > > What are you using to program the EPROM? Can you send me a copy of > > the corrected program? __________________________________

(You need to be a member of m68hc11 -- send a blank email to m68hc11-subscribe@yahoogroups.com )