john@wa3wbu.UUCP (John Gayman) (03/08/88)
I'm having a slight problem with a Prom burner that maybe one of you has already run across. The problem seems to be a failure when writing to the Prom. I work almost exclusively with 256K Prom's. What happens is I can read a Prom but then when I go to write that information onto a new Prom, it bombs out at address 4000. It always stops at 4000! I've tried lots of Proms including some new ones and strange enough a couple of the new ones worked but a lot of them failed the same way. Someone mentioned to be that maybe they aren't being erased fully. The status checker on the Prom burner indicates a blank Prom. Other people have indicated that its an interrupt conflict on the bus. I *did* try a few smaller Proms and they all worked fine. Any ideas ?? Things to check ? As usual, all input is appreciated. John -- John Gayman, WA3WBU | UUCP: uunet!wa3wbu!john 1869 Valley Rd. | ARPA: wa3wbu!john@uunet.UU.NET Marysville, PA 17053 | Packet: WA3WBU @ AK3P
jru@etn-rad.UUCP (John Unekis) (03/10/88)
In article <523@wa3wbu.UUCP> john@wa3wbu.UUCP (John Gayman) writes: > > I'm having a slight problem with a Prom burner that maybe one of you >has already run across. The problem seems to be a failure when writing >a new Prom, it bombs out at address 4000. It always stops at 4000! I've .... Check the amount of memory that is actually located in your prom burner. Most prom burners were designed back when a 4K prom was REALLY BIG. Address 4000 hex is 16K in decimal, thats about the total memory available on a lot of prom burners. If this proves to be the case with your machine, you will need to either add memory, or program the machine to burn the prom in several (like 16) passes. Pass 1 would read 16K starting at address 0, then write 16K at address 0, pass 2 would read 16K starting at address 4000, then write 16K at address 4000 (pass1 would go 0-3FFF, pass2 would go 4000-7FFF) etc. till you get to 3FFFF. This may seem like a royal pain, but it just goes to show that technology is advancing faster than it can propagate into the supporting structure of most companies. Just wait a couple of years until microprocessors hit the multiple 100 MIPS range, and circuit boards will start radiating microwaves. Imagine your PC locked in a lead box to protect you from harmful radiations. It wont be long!
markz@ssc.UUCP (Markz Zenier) (03/10/88)
In article <523@wa3wbu.UUCP>, john@wa3wbu.UUCP (John Gayman) writes: > > I'm having a slight problem with a Prom burner that maybe one of you > has already run across. The problem seems to be a failure when writing > to the Prom. I work almost exclusively with 256K Prom's. What happens is > I can read a Prom but then when I go to write that information onto > a new Prom, it bombs out at address 4000. It always stops at 4000! I've > ... Try putting a 'scope on the address pins of the prom, you may have a fried pin driver which is aliasing the addresses. Also the socket may be open, If the programmer has had a lot of use, and is a cheap one with 3M/Textool sockets (the blue green ones) soldered directly to the board. The AMP sales rep (a competitor) said that the pins on the bottom of a Textool socket flex a little when the zif lever is worked, causing metal fatigue in the solder.