[sdiy] Re: EPROM Burning Question

[Tim Curtis]

Okay, I just figured out part of the problem and will promptly strike 
myself repeatedly in the head...

We're talking about KiloBYTES for the ram buffer and KiloBITS for the 
EPROM.  My brain shut down...

Still, can anyone help me figure out the problem with the error at $4000 
on both EPROMs?  I'm still lost on that one.

Thanks,


Tim



Tim Curtis wrote:

> Hi Everyone -
>
> I'm stuck with what is probably a stupidly simple problem, but 
> apparently I'm more of an idiot today than I normally am...
>
> I've got an EPROM burner here on my PC - it's a "Modular Circuit 
> Technology MOD-MEP" - that I've been using with no problems whatsoever 
> thus far.
> According to the specs it will suport EPROMS up to the 271024.  Up 
> until now I've been using it with smaller devices, limited to the 2764 
> and smaller.
>
> This unit has software that runs under DOS and is rather archaic to be 
> honest.  It's software has you load a .bin file into a buffer before 
> programming the EPROM.  According to both the manual and the software 
> options, the buffer is selectable between 64K and 128K - obviously 
> smaller than some of the supported devices.
>
> I'm trying to program a couple of 27256's for a software upgrade for 
> my K150 and have run into a problem where every time I program an 
> EPROM  I get a bad checksum (always the same) and find that there is 
> an error on the programmed EPROM at $4000, again always the same - $40 
> instead of $46 as it should be.
>
> I've tried programming the 27264 in two sections ($0000 to $3FFF, 
> $4000 to $7FFF) and I've tried programming it in it's entirety, both 
> numerous times) and I keep coming up with the same problem.  I also 
> encounter the same problem programming the second EPROM for the K150 - 
> different hex but at the same address of $4000.
>
> Obviously this is the first address of the second 128K.
>
> I admit to being suprised that I can program it in one shot at all, 
> with the 128K buffer size.  This isn't exlained at all in the manual,
>
> Does anyone have any ideas or suggestions as to what I'm doing wrong?
>
> Thanks,
>
> Tim
>